1
|
Sen S, Woodhouse MR, Portwood JL, Andorf CM. Maize Feature Store: A centralized resource to manage and analyze curated maize multi-omics features for machine learning applications. Database (Oxford) 2023; 2023:baad078. [PMID: 37935586 PMCID: PMC10634621 DOI: 10.1093/database/baad078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2022] [Revised: 09/16/2023] [Accepted: 10/19/2023] [Indexed: 11/09/2023]
Abstract
The big-data analysis of complex data associated with maize genomes accelerates genetic research and improves agronomic traits. As a result, efforts have increased to integrate diverse datasets and extract meaning from these measurements. Machine learning models are a powerful tool for gaining knowledge from large and complex datasets. However, these models must be trained on high-quality features to succeed. Currently, there are no solutions to host maize multi-omics datasets with end-to-end solutions for evaluating and linking features to target gene annotations. Our work presents the Maize Feature Store (MFS), a versatile application that combines features built on complex data to facilitate exploration, modeling and analysis. Feature stores allow researchers to rapidly deploy machine learning applications by managing and providing access to frequently used features. We populated the MFS for the maize reference genome with over 14 000 gene-based features based on published genomic, transcriptomic, epigenomic, variomic and proteomics datasets. Using the MFS, we created an accurate pan-genome classification model with an AUC-ROC score of 0.87. The MFS is publicly available through the maize genetics and genomics database. Database URL https://mfs.maizegdb.org/.
Collapse
Affiliation(s)
- Shatabdi Sen
- Department of Plant Pathology & Microbiology, Iowa State University, 1344 Advanced Teaching & Research Bldg, 2213 Pammel Dr, Ames, IA 50011, USA
| | - Margaret R Woodhouse
- USDA-ARS, Corn Insects and Crop Genetics Research Unit, 819 Wallace Road, Ames, IA 50011, USA
| | - John L Portwood
- USDA-ARS, Corn Insects and Crop Genetics Research Unit, 819 Wallace Road, Ames, IA 50011, USA
| | - Carson M Andorf
- USDA-ARS, Corn Insects and Crop Genetics Research Unit, 819 Wallace Road, Ames, IA 50011, USA
- Department of Computer Science, Iowa State University, Atanasoff Hall, 2434 Osborn Dr, Ames, IA 50011, USA
| |
Collapse
|
2
|
Marcotrigiano AR, Carluccio AV, Unachukwu N, Adeoti SR, Abdulsalam T, Gedil M, Menkir A, Gisel A, Stavolone L. Hydroxamic acids: New players in the multifactorial mechanisms of maize resistance to Striga hermonthica. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2023; 204:108134. [PMID: 37883916 DOI: 10.1016/j.plaphy.2023.108134] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Revised: 09/25/2023] [Accepted: 10/21/2023] [Indexed: 10/28/2023]
Abstract
Striga hermonthica is the most widespread and destructive plant parasite infesting maize and other major crops in sub-Saharan Africa where it causes severe yield losses and threatens food security. Several tolerant maize lines supporting reduced S. hermonthica emergence have been deployed. However, the molecular bases of such resistance are yet poorly understood. Based on a time course comparative gene expression analysis between susceptible and resistant maize lines we have confirmed resistance mechanisms known to be activated upon plant parasite infestation and identified potential novel players worth further investigation e.g. iron homeostasis and mitochondrial respiration-related genes. Most intriguingly, we show a previously unknown strategy of maize post-attachment resistance based on DIMBOA accumulation in S. hermonthica-infested maize roots. S. hermonthica infestation triggers positive regulation of gene expression in the hydroxamic acid (HA) pathway culminating with an accumulation of benzoxazinoids (BX), known for their antifeedant, insecticidal, antimicrobial, and allelopathic activities. We demonstrate that HA root content is positively correlated with S. hermonthica resistance in the resistant parent and its progenies and in unrelated maize lines. Downregulation of HA genes causes increased susceptibility to S. hermonthica infestation in loss-of-function maize mutants. While the mechanism of BX action in parasitic plant resistance is yet to be uncovered, the potential of this discovery for developing effective control and breeding strategies is enormous.
Collapse
Affiliation(s)
- Angelo Raffaele Marcotrigiano
- International Institute of Tropical Agriculture, Ibadan, Nigeria; Department of Soil, Plant and Food Sciences, University of Bari, Italy
| | - Anna Vittoria Carluccio
- International Institute of Tropical Agriculture, Ibadan, Nigeria; Institute for Sustainable Plant Protection, CNR, Bari, Italy
| | - Nnanna Unachukwu
- International Institute of Tropical Agriculture, Ibadan, Nigeria
| | | | - Toyin Abdulsalam
- International Institute of Tropical Agriculture, Ibadan, Nigeria
| | - Melaku Gedil
- International Institute of Tropical Agriculture, Ibadan, Nigeria
| | - Abebe Menkir
- International Institute of Tropical Agriculture, Ibadan, Nigeria
| | - Andreas Gisel
- International Institute of Tropical Agriculture, Ibadan, Nigeria; Institute for Biomedical Technologies, CNR, Bari, Italy
| | - Livia Stavolone
- International Institute of Tropical Agriculture, Ibadan, Nigeria; Institute for Sustainable Plant Protection, CNR, Bari, Italy.
| |
Collapse
|
3
|
Ellison EL, Zhou P, Hermanson P, Chu YH, Read A, Hirsch CN, Grotewold E, Springer NM. Mutator transposon insertions within maize genes often provide a novel outward reading promoter. Genetics 2023; 225:iyad171. [PMID: 37815810 DOI: 10.1093/genetics/iyad171] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Accepted: 09/04/2023] [Indexed: 10/11/2023] Open
Abstract
The highly active family of Mutator (Mu) DNA transposons has been widely used for forward and reverse genetics in maize. There are examples of Mu-suppressible alleles that result in conditional phenotypic effects based on the activity of Mu. Phenotypes from these Mu-suppressible mutations are observed in Mu-active genetic backgrounds, but absent when Mu activity is lost. For some Mu-suppressible alleles, phenotypic suppression likely results from an outward-reading promoter within Mu that is only active when the autonomous Mu element is silenced or lost. We isolated 35 Mu alleles from the UniformMu population that represent insertions in 24 different genes. Most of these mutant alleles are due to insertions within gene coding sequences, but several 5' UTR and intron insertions were included. RNA-seq and de novo transcript assembly were utilized to document the transcripts produced from 33 of these Mu insertion alleles. For 20 of the 33 alleles, there was evidence of transcripts initiating within the Mu sequence reading through the gene. This outward-reading promoter activity was detected in multiple types of Mu elements and does not depend on the orientation of Mu. Expression analyses of Mu-initiated transcripts revealed the Mu promoter often provides gene expression levels and patterns that are similar to the wild-type gene. These results suggest the Mu promoter may represent a minimal promoter that can respond to gene cis-regulatory elements. Findings from this study have implications for maize researchers using the UniformMu population, and more broadly highlight a strategy for transposons to co-exist with their host.
Collapse
Affiliation(s)
- Erika L Ellison
- Department of Plant and Microbial Biology, University of Minnesota, Saint Paul, MN 55108, USA
| | - Peng Zhou
- Department of Plant and Microbial Biology, University of Minnesota, Saint Paul, MN 55108, USA
| | - Peter Hermanson
- Department of Plant and Microbial Biology, University of Minnesota, Saint Paul, MN 55108, USA
| | - Yi-Hsuan Chu
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824, USA
| | - Andrew Read
- Department of Plant and Microbial Biology, University of Minnesota, Saint Paul, MN 55108, USA
- Department of Agronomy and Plant Genetics, University of Minnesota, Saint Paul, MN 55108, USA
| | - Candice N Hirsch
- Department of Agronomy and Plant Genetics, University of Minnesota, Saint Paul, MN 55108, USA
| | - Erich Grotewold
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824, USA
| | - Nathan M Springer
- Department of Plant and Microbial Biology, University of Minnesota, Saint Paul, MN 55108, USA
| |
Collapse
|
4
|
Hunter CT, McCarty DR, Koch KE. Independent evolution of transposase and TIRs facilitated by recombination between Mutator transposons from divergent clades in maize. Proc Natl Acad Sci U S A 2023; 120:e2305298120. [PMID: 37490540 PMCID: PMC10401008 DOI: 10.1073/pnas.2305298120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Accepted: 05/25/2023] [Indexed: 07/27/2023] Open
Abstract
Nearly all eukaryotes carry DNA transposons of the Robertson's Mutator (Mu) superfamily, a widespread source of genome instability and genetic variation. Despite their pervasive impact on host genomes, much remains unknown about the evolution of these transposons. Transposase recognition of terminal inverted repeats (TIRs) is thought to drive and constrain coevolution of MuDR transposase genes and TIRs. To address the extent of this relationship and its impact, we compared separate phylogenies of TIRs and MuDR gene sequences from Mu elements in the maize genome. Five major clades were identified. As expected, most Mu elements were bound by highly similar TIRs from the same clade (homomorphic type). However, a subset of elements contained dissimilar TIRs derived from divergent clades. These "heteromorphs" typically occurred in multiple copies indicating active transposition in the genome. In addition, analysis of internal sequences showed that exchanges between elements having divergent TIRs produced new mudra and mudrb gene combinations. In several instances, TIR homomorphs had been regenerated within a heteromorph clade with retention of distinctive internal MuDR sequence combinations. Results reveal that recombination between divergent clades facilitates independent evolution of transposase (mudra), transposase-binding targets (TIRs), and capacity for insertion (mudrb) of active Mu elements. This mechanism would be enhanced by the preference of Mu insertions for recombination-rich regions near the 5' ends of genes. We suggest that cycles of recombination give rise to alternating homo- and heteromorph forms that enhance the diversity on which selection for Mu fitness can operate.
Collapse
Affiliation(s)
- Charles T. Hunter
- Chemistry Research Unit, Center for Medical, Agricultural and Veterinary Entomology, United States Department of Agriculture - Agricultural Research Service, Gainesville, FL32608
| | - Donald R. McCarty
- Horticultural Sciences Department, College of Agricultural and Life Sciences, University of Florida, Gainesville, FL32611
| | - Karen E. Koch
- Horticultural Sciences Department, College of Agricultural and Life Sciences, University of Florida, Gainesville, FL32611
| |
Collapse
|
5
|
Guan JC, Li C, Flint-Garcia S, Suzuki M, Wu S, Saunders JW, Dong L, Bouwmeester HJ, McCarty DR, Koch KE. Maize domestication phenotypes reveal strigolactone networks coordinating grain size evolution with kernel-bearing cupule architecture. THE PLANT CELL 2023; 35:1013-1037. [PMID: 36573016 PMCID: PMC10015167 DOI: 10.1093/plcell/koac370] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Accepted: 11/15/2022] [Indexed: 06/17/2023]
Abstract
The maize (Zea mays) ear represents one of the most striking domestication phenotypes in any crop species, with the cob conferring an exceptional yield advantage over the ancestral form of teosinte. Remodeling of the grain-bearing surface required profound developmental changes. However, the underlying mechanisms remain unclear and can only be partly attributed to the known domestication gene Teosinte glume architecture 1 (Tga1). Here we show that a more complete conversion involves strigolactones (SLs), and that these are prominent players not only in the Tga1 phenotype but also other domestication features of the ear and kernel. Genetic combinations of a teosinte tga1 allele with three SL-related mutants progressively enhanced ancestral morphologies. The SL mutants, in addition to modulating the tga1 phenotype, also reshaped kernel-bearing pedicels and cupules in a teosinte-like manner. Genetic and molecular evidence are consistent with SL regulation of TGA1, including direct interaction of TGA1 with components of the SL-signaling system shown here to mediate TGA1 availability by sequestration. Roles of the SL network extend to enhancing maize seed size and, importantly, coordinating increased kernel growth with remodeling of protective maternal tissues. Collectively, our data show that SLs have central roles in releasing kernels from restrictive maternal encasement and coordinating other factors that increase kernel size, physical support, and their exposure on the grain-bearing surface.
Collapse
Affiliation(s)
- Jiahn-Chou Guan
- Horticultural Sciences Department, University of Florida, Gainesville, Florida 32610, USA
- Plant Molecular and Cellular Biology Program, University of Florida, Gainesville, Florida 32610, USA
- Genetics Institute, University of Florida, Gainesville, Florida 32610, USA
| | - Changsheng Li
- Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam 100 BE, The Netherlands
| | - Sherry Flint-Garcia
- United States Department of Agriculture – Agricultural Research Service, Columbia, Missouri 65211, USA
| | - Masaharu Suzuki
- Horticultural Sciences Department, University of Florida, Gainesville, Florida 32610, USA
- Plant Molecular and Cellular Biology Program, University of Florida, Gainesville, Florida 32610, USA
- Genetics Institute, University of Florida, Gainesville, Florida 32610, USA
| | - Shan Wu
- Horticultural Sciences Department, University of Florida, Gainesville, Florida 32610, USA
| | - Jonathan W Saunders
- Horticultural Sciences Department, University of Florida, Gainesville, Florida 32610, USA
| | - Lemeng Dong
- Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam 100 BE, The Netherlands
| | - Harro J Bouwmeester
- Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam 100 BE, The Netherlands
| | - Donald R McCarty
- Horticultural Sciences Department, University of Florida, Gainesville, Florida 32610, USA
- Plant Molecular and Cellular Biology Program, University of Florida, Gainesville, Florida 32610, USA
- Genetics Institute, University of Florida, Gainesville, Florida 32610, USA
| | - Karen E Koch
- Horticultural Sciences Department, University of Florida, Gainesville, Florida 32610, USA
- Plant Molecular and Cellular Biology Program, University of Florida, Gainesville, Florida 32610, USA
- Genetics Institute, University of Florida, Gainesville, Florida 32610, USA
| |
Collapse
|
6
|
Wu H, Li G, Zhan J, Zhang S, Beall BD, Yadegari R, Becraft PW. Rearrangement with the nkd2 promoter contributed to allelic diversity of the r1 gene in maize (Zea mays). THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2022; 111:1701-1716. [PMID: 35876146 PMCID: PMC9546038 DOI: 10.1111/tpj.15918] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Revised: 06/13/2022] [Accepted: 07/15/2022] [Indexed: 06/15/2023]
Abstract
The maize red1 (r1) locus regulates anthocyanin accumulation and is a classic model for allelic diversity; changes in regulatory regions are responsible for most of the variation in gene expression patterns. Here, an intrachromosomal rearrangement between the distal upstream region of r1 and the region of naked endosperm 2 (nkd2) upstream to the third exon generated a nkd2 null allele lacking the first three exons, and the R1-st (stippled) allele with a novel r1 5' promoter region homologous to 5' regions from nkd2-B73. R1-sc:124 (an R1-st derivative) shows increased and earlier expression than a standard R1-g allele, as well as ectopic expression in the starchy endosperm compartment. Laser capture microdissection and RNA sequencing indicated that ectopic R1-sc:124 expression impacted expression of genes associated with RNA modification. The expression of R1-sc:124 resembled nkd2-W22 expression, suggesting that nkd2 regulatory sequences may influence the expression of R1-sc:124. The r1-sc:m3 allele is derived from R1-sc:124 by an insertion of a Ds6 transposon in intron 4. This insertion blocks anthocyanin regulation by causing mis-splicing that eliminates exon 5 from the mRNA. This allele serves as an important launch site for Ac/Ds mutagenesis studies, and two Ds6 insertions believed to be associated with nkd2 mutant alleles were actually located in the r1 5' region. Among annotated genomes of teosinte and maize varieties, the nkd2 and r1 loci showed conserved overall gene structures, similar to the B73 reference genome, suggesting that the nkd2-r1 rearrangement may be a recent event.
Collapse
Affiliation(s)
- Hao Wu
- Genetics, Development and Cell Biology DepartmentIowa State UniversityAmesIowaUSA
- Present address:
School of Integrative Plant ScienceCornell UniversityIthacaNew York14853USA
| | - Guosheng Li
- School of Plant SciencesUniversity of ArizonaTucsonArizona85721USA
| | - Junpeng Zhan
- School of Plant SciencesUniversity of ArizonaTucsonArizona85721USA
- Present address:
Donald Danforth Plant Science CenterSt. LouisMissouri63132USA
| | - Shanshan Zhang
- School of Plant SciencesUniversity of ArizonaTucsonArizona85721USA
| | - Brandon D. Beall
- Genetics, Development and Cell Biology DepartmentIowa State UniversityAmesIowaUSA
- Agronomy DepartmentIowa State UniversityAmesIowa50011USA
| | - Ramin Yadegari
- School of Plant SciencesUniversity of ArizonaTucsonArizona85721USA
| | - Philip W. Becraft
- Genetics, Development and Cell Biology DepartmentIowa State UniversityAmesIowaUSA
- Agronomy DepartmentIowa State UniversityAmesIowa50011USA
| |
Collapse
|
7
|
Wang D, Yu C, Zhang J, Peterson T. Excision and reinsertion of Ac macrotransposons in maize. Genetics 2022; 221:iyac067. [PMID: 35471241 PMCID: PMC9339288 DOI: 10.1093/genetics/iyac067] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Accepted: 04/18/2022] [Indexed: 11/13/2022] Open
Abstract
Eukaryotic Macrotransposons (MTns) can be formed by 2 nearby elements flanking a segment of host DNA. The maize Ac transposon can form Ac::MTns, but little is known about Ac::MTn transposition activities. Here, we studied 3 Ac::MTns at the maize p1 locus, each of which is composed of a segment of maize p1 genomic DNA (up to 15 kb) bounded by a fractured Ac element (fAc, 2039 bp), and a full-length Ac element in direct orientation. The resulting Ac::MTns are of 16, 16.5, and 22 kb total length. From these 3 Ac::MTns, we identified 10 independent cases of macrotransposition, and observed similar features of transposition between Ac::MTn and standard Ac/Ds, including characteristic excision footprints and insertion target site duplications. Nine out of the 10 Ac::MTn reinsertion targets were genetically linked to the donor sites, another similarity with Ac/Ds standard transposition. We also identified a MTn-like structure in the maize B73 reference genome and 5 NAM founder lines. The MTn in diverse lines is flanked by target site duplications, confirming the historic occurrence of MTn transposition during genome evolution. Our results show that Ac::MTns are capable of mobilizing segments of DNA long enough to include a typical full-length plant gene and in theory could erode gene colinearity in syntenic regions during plant genome evolution.
Collapse
Affiliation(s)
- Dafang Wang
- Division of Math and Sciences, Delta State University, Cleveland, MS 38733-0001, USA
| | - Chuanhe Yu
- The Hormel Institute, University of Minnesota, Austin, MN 55912, USA
| | - Jianbo Zhang
- Department of Horticultural Science, Mountain Horticultural Crops Research and Extension Center, North Carolina State University, Mills River, NC 28759, USA
| | - Thomas Peterson
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, IA 50011-3260, USA
- Department of Agronomy, Iowa State University, Ames, IA 50011-3260, USA
| |
Collapse
|
8
|
Liu Z, Abou-Elwafa SF, Xie J, Liu Y, Li S, Aljabri M, Zhang D, Gao F, Zhang L, Wang Z, Sun C, Zhu B, Bao M, Hu X, Chen Y, Ku L, Ren Z, Wei L. A Nucleoporin NUP58 modulates responses to drought and salt stress in maize (Zea mays L.). PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2022; 320:111296. [PMID: 35643613 DOI: 10.1016/j.plantsci.2022.111296] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Revised: 04/09/2022] [Accepted: 04/18/2022] [Indexed: 06/15/2023]
Abstract
Nuclear pore complex (NUP) is the main transport channel between cytoplasm and nucleoplasm, which plays an important role in stress response. The function of NUPs was widely reported in yeast and vertebrate but rarely in plants. Here, we identified a nuclear pore complex (ZmNUP58), that is tightly associated with drought and salt tolerance phenotype accompanied with phenotypic and physiological changes under drought and salt stress. The overexpression of ZmNUP58 in maize (Zea mays L.) significantly promotes both chlorophyll content and activities of antioxidant enzymes under drought- and salt-stressed conditions. RNA-Seq analysis showed that ZmNUP58 could regulate the expression of genes related to phytohormone synthesis and signaling, osmotic adjustment substances, antioxidant enzyme system, cell wall biosynthesis, glucose metabolism and aquaporin. The results provide novel insights into the regulatory role of ZmNUP58 in improving drought and salt tolerance through regulating phytohormone and other stress response genes in maize.
Collapse
Affiliation(s)
- Zhixue Liu
- Synergetic Innovation Center of Henan Grain Crops and National Key Laboratory of Wheat and Maize Crop Science, Henan Agricultural University, Zhengzhou, Henan, 450046, China
| | | | - Jiarong Xie
- Synergetic Innovation Center of Henan Grain Crops and National Key Laboratory of Wheat and Maize Crop Science, Henan Agricultural University, Zhengzhou, Henan, 450046, China
| | - Yajing Liu
- Synergetic Innovation Center of Henan Grain Crops and National Key Laboratory of Wheat and Maize Crop Science, Henan Agricultural University, Zhengzhou, Henan, 450046, China
| | - Siyuan Li
- Corn Breeding and Research, China Seeds International Seeds Co., Ltd, Zhengzhou, Henan, 450046, China
| | - Maha Aljabri
- Department of Biology, Faculty of Applied Science, Umm Al-Qura University, Makkah 21421, Saudi Arabia
| | - Dongling Zhang
- Synergetic Innovation Center of Henan Grain Crops and National Key Laboratory of Wheat and Maize Crop Science, Henan Agricultural University, Zhengzhou, Henan, 450046, China
| | - Fengran Gao
- Synergetic Innovation Center of Henan Grain Crops and National Key Laboratory of Wheat and Maize Crop Science, Henan Agricultural University, Zhengzhou, Henan, 450046, China
| | - Lili Zhang
- Synergetic Innovation Center of Henan Grain Crops and National Key Laboratory of Wheat and Maize Crop Science, Henan Agricultural University, Zhengzhou, Henan, 450046, China
| | - Zhiyong Wang
- Synergetic Innovation Center of Henan Grain Crops and National Key Laboratory of Wheat and Maize Crop Science, Henan Agricultural University, Zhengzhou, Henan, 450046, China
| | - Chongyu Sun
- Synergetic Innovation Center of Henan Grain Crops and National Key Laboratory of Wheat and Maize Crop Science, Henan Agricultural University, Zhengzhou, Henan, 450046, China
| | - Bingqi Zhu
- Synergetic Innovation Center of Henan Grain Crops and National Key Laboratory of Wheat and Maize Crop Science, Henan Agricultural University, Zhengzhou, Henan, 450046, China
| | - Miaomiao Bao
- Synergetic Innovation Center of Henan Grain Crops and National Key Laboratory of Wheat and Maize Crop Science, Henan Agricultural University, Zhengzhou, Henan, 450046, China
| | - Xiaomeng Hu
- Synergetic Innovation Center of Henan Grain Crops and National Key Laboratory of Wheat and Maize Crop Science, Henan Agricultural University, Zhengzhou, Henan, 450046, China
| | - Yanhui Chen
- Synergetic Innovation Center of Henan Grain Crops and National Key Laboratory of Wheat and Maize Crop Science, Henan Agricultural University, Zhengzhou, Henan, 450046, China
| | - Lixia Ku
- Synergetic Innovation Center of Henan Grain Crops and National Key Laboratory of Wheat and Maize Crop Science, Henan Agricultural University, Zhengzhou, Henan, 450046, China
| | - Zhenzhen Ren
- Synergetic Innovation Center of Henan Grain Crops and National Key Laboratory of Wheat and Maize Crop Science, Henan Agricultural University, Zhengzhou, Henan, 450046, China.
| | - Li Wei
- Synergetic Innovation Center of Henan Grain Crops and National Key Laboratory of Wheat and Maize Crop Science, Henan Agricultural University, Zhengzhou, Henan, 450046, China.
| |
Collapse
|
9
|
Chen P, Michel AH, Zhang J. Transposon insertional mutagenesis of diverse yeast strains suggests coordinated gene essentiality polymorphisms. Nat Commun 2022; 13:1490. [PMID: 35314699 PMCID: PMC8938418 DOI: 10.1038/s41467-022-29228-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Accepted: 03/01/2022] [Indexed: 12/18/2022] Open
Abstract
Due to epistasis, the same mutation can have drastically different phenotypic consequences in different individuals. This phenomenon is pertinent to precision medicine as well as antimicrobial drug development, but its general characteristics are largely unknown. We approach this question by genome-wide assessment of gene essentiality polymorphism in 16 Saccharomyces cerevisiae strains using transposon insertional mutagenesis. Essentiality polymorphism is observed for 9.8% of genes, most of which have had repeated essentiality switches in evolution. Genes exhibiting essentiality polymorphism lean toward having intermediate numbers of genetic and protein interactions. Gene essentiality changes tend to occur concordantly among components of the same protein complex or metabolic pathway and among a group of over 100 mitochondrial proteins, revealing molecular machines or functional modules as units of gene essentiality variation. Most essential genes tolerate transposon insertions consistently among strains in one or more coding segments, delineating nonessential regions within essential genes.
Collapse
Affiliation(s)
- Piaopiao Chen
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Agnès H Michel
- Department of Biochemistry, University of Oxford, Oxford, OX1 3QU, UK
| | - Jianzhi Zhang
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI, 48109, USA.
| |
Collapse
|
10
|
Wang Z, Zhao X, Ren Z, Abou-Elwafa SF, Pu X, Zhu Y, Dou D, Su H, Cheng H, Liu Z, Chen Y, Wang E, Shao R, Ku L. ZmERF21 directly regulates hormone signaling and stress-responsive gene expression to influence drought tolerance in maize seedlings. PLANT, CELL & ENVIRONMENT 2022; 45:312-328. [PMID: 34873716 DOI: 10.1111/pce.14243] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Revised: 11/27/2021] [Accepted: 11/30/2021] [Indexed: 06/13/2023]
Abstract
Drought stress adversely impacts crop development and yield. Maize frequently encounters drought stress during its life cycle. Improvement of drought tolerance is a priority of maize breeding programs. Here, we identified a novel transcription factor encoding gene, APETALA2 (AP2)/Ethylene response factor (ERF), which is tightly associated with drought tolerance in maize seedlings. ZmERF21 is mainly expressed in the root and leaf and it can be highly induced by polyethylene glycol treatment. Genetic analysis showed that the zmerf21 mutant plants displayed a reduced drought tolerance phenotype, accompanied by phenotypical and physiological changes that are commonly observed in drought conditions. Overexpression of ZmERF21 in maize significantly increased the chlorophyll content and activities of antioxidant enzymes under drought conditions. RNA-Seq and DNA affinity purification sequencing analysis further revealed that ZmERF21 may directly regulate the expression of genes related to hormone (ethylene, abscisic acid) and Ca signaling as well as other stress-response genes through binding to the promoters of potential target genes. Our results thereby provided molecular evidence of ZmERF21 is involved in the drought stress response of maize.
Collapse
Affiliation(s)
- Zhiyong Wang
- National Key Laboratory of Wheat and Maize Crop Science, Laboratory of Regulating and Controlling Crop Growth and Development Ministry of Education, Henan Agricultural University, Zhengzhou, Henan, China
| | - Xiang Zhao
- State Key Laboratory of Crop Stress Adaptation and Improvement, State Key Laboratory of Cotton Biology, School of Life Sciences, Henan University, Kaifeng, China
| | - Zhenzhen Ren
- National Key Laboratory of Wheat and Maize Crop Science, Laboratory of Regulating and Controlling Crop Growth and Development Ministry of Education, Henan Agricultural University, Zhengzhou, Henan, China
| | | | - Xiaoyu Pu
- National Key Laboratory of Wheat and Maize Crop Science, Laboratory of Regulating and Controlling Crop Growth and Development Ministry of Education, Henan Agricultural University, Zhengzhou, Henan, China
| | - Yingfang Zhu
- State Key Laboratory of Crop Stress Adaptation and Improvement, State Key Laboratory of Cotton Biology, School of Life Sciences, Henan University, Kaifeng, China
| | - Dandan Dou
- National Key Laboratory of Wheat and Maize Crop Science, Laboratory of Regulating and Controlling Crop Growth and Development Ministry of Education, Henan Agricultural University, Zhengzhou, Henan, China
| | - Huihui Su
- National Key Laboratory of Wheat and Maize Crop Science, Laboratory of Regulating and Controlling Crop Growth and Development Ministry of Education, Henan Agricultural University, Zhengzhou, Henan, China
| | - Haiyang Cheng
- National Key Laboratory of Wheat and Maize Crop Science, Laboratory of Regulating and Controlling Crop Growth and Development Ministry of Education, Henan Agricultural University, Zhengzhou, Henan, China
| | - Zhixue Liu
- National Key Laboratory of Wheat and Maize Crop Science, Laboratory of Regulating and Controlling Crop Growth and Development Ministry of Education, Henan Agricultural University, Zhengzhou, Henan, China
| | - Yanhui Chen
- National Key Laboratory of Wheat and Maize Crop Science, Laboratory of Regulating and Controlling Crop Growth and Development Ministry of Education, Henan Agricultural University, Zhengzhou, Henan, China
| | - Ertao Wang
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Ruixin Shao
- National Key Laboratory of Wheat and Maize Crop Science, Laboratory of Regulating and Controlling Crop Growth and Development Ministry of Education, Henan Agricultural University, Zhengzhou, Henan, China
| | - Lixia Ku
- National Key Laboratory of Wheat and Maize Crop Science, Laboratory of Regulating and Controlling Crop Growth and Development Ministry of Education, Henan Agricultural University, Zhengzhou, Henan, China
| |
Collapse
|
11
|
Riggs P, Blundell-Hunter G, Hagelberger J, Ren G, Ettwiller L, Berkmen M. Insertion Specificity of the hATx-6 Transposase of Hydra magnipapillata. Front Mol Biosci 2022; 8:734154. [PMID: 34988112 DOI: 10.3389/fmolb.2021.734154] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Accepted: 11/10/2021] [Indexed: 01/22/2023] Open
Abstract
Transposable elements (TE) are mobile genetic elements, present in all domains of life. They commonly encode a single transposase enzyme, that performs the excision and reintegration reactions, and these enzymes have been used in mutagenesis and creation of next-generation sequencing libraries. All transposases have some bias in the DNA sequence they bind to when reintegrating the TE DNA. We sought to identify a transposase that showed minimal sequence bias and could be produced recombinantly, using information from the literature and a novel bioinformatic analysis, resulting in the selection of the hATx-6 transposase from Hydra vulgaris (aka Hydra magnipapillata) for further study. This transposase was tested and shown to be active both in vitro and in vivo, and we were able to demonstrate very low sequence bias in its integration preference. This transposase could be an excellent candidate for use in biotechnology, such as the creation of next-generation sequencing libraries.
Collapse
Affiliation(s)
- Paul Riggs
- New England Biolabs, Ipswich, MA, United States
| | | | | | - Guoping Ren
- New England Biolabs, Ipswich, MA, United States
| | | | | |
Collapse
|
12
|
Lyu M, Liu H, Waititu JK, Sun Y, Wang H, Fu J, Chen Y, Liu J, Ku L, Cheng X. TEAseq-based identification of 35,696 Dissociation insertional mutations facilitates functional genomic studies in maize. J Genet Genomics 2021; 48:961-971. [PMID: 34654681 DOI: 10.1016/j.jgg.2021.07.010] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 07/11/2021] [Accepted: 07/17/2021] [Indexed: 11/26/2022]
Abstract
In plants, transposable element (TE)-triggered mutants are important resources for functional genomic studies. However, conventional approaches for genome-wide identification of TE insertion sites are costly and laborious. This study developed a novel, rapid, and high-throughput TE insertion site identification workflow based on next-generation sequencing and named it Transposable Element Amplicon Sequencing (TEAseq). Using TEAseq, we systemically profiled the Dissociation (Ds) insertion sites in 1606 independent Ds insertional mutants in advanced backcross generation using K17 as background. The Ac-containing individuals were excluded for getting rid of the potential somatic insertions. We characterized 35,696 germinal Ds insertions tagging 10,323 genes, representing approximately 23.3% of the total genes in the maize genome. The insertion sites were presented in chromosomal hotspots around the ancestral Ds loci, and insertions occurred preferentially in gene body regions. Furthermore, we mapped a loss-of-function AGL2 gene using bulked segregant RNA-sequencing assay and proved that AGL2 is essential for seed development. We additionally established an open-access database named MEILAM for easy access to Ds insertional mutations. Overall, our results have provided an efficient workflow for TE insertion identification and rich sequence-indexed mutant resources for maize functional genomic studies.
Collapse
Affiliation(s)
- Mingjie Lyu
- Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Huafeng Liu
- College of Agronomy, Collaborative Innovation Center of Henan Grain Crops and National Key Laboratory of Wheat and Maize Crop Science, Henan Agricultural University, Zhengzhou, Henan 450002, China
| | - Joram Kiriga Waititu
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Ying Sun
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Huan Wang
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Junjie Fu
- Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Yanhui Chen
- College of Agronomy, Collaborative Innovation Center of Henan Grain Crops and National Key Laboratory of Wheat and Maize Crop Science, Henan Agricultural University, Zhengzhou, Henan 450002, China
| | - Jun Liu
- Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
| | - Lixia Ku
- College of Agronomy, Collaborative Innovation Center of Henan Grain Crops and National Key Laboratory of Wheat and Maize Crop Science, Henan Agricultural University, Zhengzhou, Henan 450002, China.
| | - Xiliu Cheng
- Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
| |
Collapse
|
13
|
Zakharenko LP. Phenotypically Unstable Mutations as Markers of Chromosomal Rearrangements Involving DNA Transposons. RUSS J GENET+ 2021. [DOI: 10.1134/s1022795421110156] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|
14
|
Noshay JM, Marand AP, Anderson SN, Zhou P, Mejia Guerra MK, Lu Z, O'Connor CH, Crisp PA, Hirsch CN, Schmitz RJ, Springer NM. Assessing the regulatory potential of transposable elements using chromatin accessibility profiles of maize transposons. Genetics 2021; 217:1-13. [PMID: 33683350 DOI: 10.1093/genetics/iyaa003] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Accepted: 11/02/2020] [Indexed: 11/14/2022] Open
Abstract
Transposable elements (TEs) have the potential to create regulatory variation both through the disruption of existing DNA regulatory elements and through the creation of novel DNA regulatory elements. In a species with a large genome, such as maize, many TEs interspersed with genes create opportunities for significant allelic variation due to TE presence/absence polymorphisms among individuals. We used information on putative regulatory elements in combination with knowledge about TE polymorphisms in maize to identify TE insertions that interrupt existing accessible chromatin regions (ACRs) in B73 as well as examples of polymorphic TEs that contain ACRs among four inbred lines of maize including B73, Mo17, W22, and PH207. The TE insertions in three other assembled maize genomes (Mo17, W22, or PH207) that interrupt ACRs that are present in the B73 genome can trigger changes to the chromatin, suggesting the potential for both genetic and epigenetic influences of these insertions. Nearly 20% of the ACRs located over 2 kb from the nearest gene are located within an annotated TE. These are regions of unmethylated DNA that show evidence for functional importance similar to ACRs that are not present within TEs. Using a large panel of maize genotypes, we tested if there is an association between the presence of TE insertions that interrupt, or carry, an ACR and the expression of nearby genes. While most TE polymorphisms are not associated with expression for nearby genes, the TEs that carry ACRs exhibit enrichment for being associated with higher expression of nearby genes, suggesting that these TEs may contribute novel regulatory elements. These analyses highlight the potential for a subset of TEs to rewire transcriptional responses in eukaryotic genomes.
Collapse
Affiliation(s)
- Jaclyn M Noshay
- Department of Plant and Microbial Biology, University of Minnesota, 140 Gortner Laboratory, 1479 Gortner Avenue, St. Paul, MN 55108, USA
| | - Alexandre P Marand
- Department of Genetics, University of Georgia, 120 W Green St, Athens, GA 30602, USA
| | - Sarah N Anderson
- Department of Genetics, Development, and Cell Biology, Iowa State University, 2437 Pammel Dr, Ames, IA 50011, USA
| | - Peng Zhou
- Department of Plant and Microbial Biology, University of Minnesota, 140 Gortner Laboratory, 1479 Gortner Avenue, St. Paul, MN 55108, USA
| | | | - Zefu Lu
- Department of Genetics, University of Georgia, 120 W Green St, Athens, GA 30602, USA
| | - Christine H O'Connor
- Department of Agronomy and Plant Genetics, University of Minnesota, 1994 Upper Buford Circle, 411 Borlaug Hall, St. Paul, MN 55108, USA
| | - Peter A Crisp
- School of Agriculture and Food Sciences, The University of Queensland, Harley Teakle Building, Keyhold Rd, St Lucia QLD 4067, Australia
| | - Candice N Hirsch
- Department of Agronomy and Plant Genetics, University of Minnesota, 1994 Upper Buford Circle, 411 Borlaug Hall, St. Paul, MN 55108, USA
| | - Robert J Schmitz
- Department of Genetics, University of Georgia, 120 W Green St, Athens, GA 30602, USA
| | - Nathan M Springer
- Department of Plant and Microbial Biology, University of Minnesota, 140 Gortner Laboratory, 1479 Gortner Avenue, St. Paul, MN 55108, USA
| |
Collapse
|
15
|
Sharma SP, Zuo T, Peterson T. Transposon-induced inversions activate gene expression in the maize pericarp. Genetics 2021; 218:iyab062. [PMID: 33905489 PMCID: PMC8225341 DOI: 10.1093/genetics/iyab062] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Accepted: 04/09/2021] [Indexed: 11/28/2022] Open
Abstract
Chromosomal inversions can have considerable biological and agronomic impacts including disrupted gene function, change in gene expression, and inhibited recombination. Here, we describe the molecular structure and functional impact of six inversions caused by Alternative Transpositions between p1 and p2 genes responsible for floral pigmentation in maize. In maize line p1-wwB54, the p1 gene is null and the p2 gene is expressed in anther and silk but not in pericarp, making the kernels white. By screening for kernels with red pericarp, we identified inversions in this region caused by transposition of Ac and fractured Ac (fAc) transposable elements. We hypothesize that these inversions place the p2 gene promoter near a p1 gene enhancer, thereby activating p2 expression in kernel pericarp. To our knowledge, this is the first report of multiple recurrent inversions that change the position of a gene promoter relative to an enhancer to induce ectopic expression in a eukaryote.
Collapse
Affiliation(s)
- Sharu Paul Sharma
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, IA 50011, USA
| | - Tao Zuo
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, IA 50011, USA
| | - Thomas Peterson
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, IA 50011, USA
- Department of Agronomy, Iowa State University, Ames, IA 50011, USA
| |
Collapse
|
16
|
Sikder MM, Vestergård M, Kyndt T, Fomsgaard IS, Kudjordjie EN, Nicolaisen M. Benzoxazinoids selectively affect maize root-associated nematode taxa. JOURNAL OF EXPERIMENTAL BOTANY 2021; 72:3835-3845. [PMID: 33712814 DOI: 10.1093/jxb/erab104] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Accepted: 03/03/2021] [Indexed: 06/12/2023]
Abstract
Although the effects of plant secondary metabolites on plant defence have been studied for decades, the exact roles of secondary metabolites in shaping plant-associated microbial and nematode communities remain elusive. We evaluated the effects of benzoxazinoids, a group of secondary metabolites present in several cereals, on root-associated nematodes. We employed 18S rRNA metabarcoding to compare maize root-associated nematode communities in a bx1 knockout maize line impaired in benzoxazinoid synthesis and in its parental wild type. Both genotype and plant age affected the composition of the nematode community in the roots, and the effects of benzoxazinoids on nematode communities were stronger in the roots than in the rhizosphere. Differential abundance analysis and quantitative PCR showed that the root lesion nematode Pratylenchus neglectus was enriched in the bx1 mutant line, while another root lesion nematode, Pratylenchus crenatus, was reduced. Correlation analysis showed that benzoxazinoid concentrations in maize roots mostly correlated negatively with the relative abundance of nematode sequence reads. However, positive correlations between benzoxazinoids and nematode taxa, including several plant-parasitic nematodes, were also identified. Our detailed nematode community analysis suggests differential and selective effects of benzoxazinoids on soil nematodes depending on both the nematode species and the benzoxazinoid compound.
Collapse
Affiliation(s)
- Md Maniruzzaman Sikder
- Department of Agroecology, Faculty of Technical Sciences, Aarhus University, 4200 Slagelse, Denmark
- Department of Botany, Faculty of Biological Sciences, Jahangirnagar University, 1342 Savar, Dhaka, Bangladesh
| | - Mette Vestergård
- Department of Agroecology, Faculty of Technical Sciences, Aarhus University, 4200 Slagelse, Denmark
| | - Tina Kyndt
- Department of Biotechnology, Faculty of Bioscience Engineering, Ghent University, 9000 Gent, Belgium
| | - Inge S Fomsgaard
- Department of Agroecology, Faculty of Technical Sciences, Aarhus University, 4200 Slagelse, Denmark
| | - Enoch Narh Kudjordjie
- Department of Agroecology, Faculty of Technical Sciences, Aarhus University, 4200 Slagelse, Denmark
| | - Mogens Nicolaisen
- Department of Agroecology, Faculty of Technical Sciences, Aarhus University, 4200 Slagelse, Denmark
| |
Collapse
|
17
|
Schrevens S, Sanglard D. Hijacking Transposable Elements for Saturation Mutagenesis in Fungi. FRONTIERS IN FUNGAL BIOLOGY 2021; 2:633876. [PMID: 37744130 PMCID: PMC10512250 DOI: 10.3389/ffunb.2021.633876] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Accepted: 03/15/2021] [Indexed: 09/26/2023]
Abstract
Transposable elements are present in almost all known genomes, these endogenous transposons have recently been referred to as the mobilome. They are now increasingly used in research in order to make extensive mutant libraries in different organisms. Fungi are an essential part of our lives on earth, they influence the availability of our food and they live inside our own bodies both as commensals and pathogenic organisms. Only few fungal species have been studied extensively, mainly due to the lack of appropriate molecular genetic tools. The use of transposon insertion libraries can however help to rapidly advance our knowledge of (conditional) essential genes, compensatory mutations and drug target identification in fungi. Here we give an overview of some recent developments in the use of different transposons for saturation mutagenesis in different fungi.
Collapse
Affiliation(s)
| | - Dominique Sanglard
- Institute of Microbiology, University of Lausanne and Lausanne University Hospital, Lausanne, Switzerland
| |
Collapse
|
18
|
Johnson A, Mcassey E, Diaz S, Reagin J, Redd PS, Parrilla DR, Nguyen H, Stec A, McDaniel LAL, Clemente TE, Stupar RM, Parrott WA, Hancock CN. Development of mPing-based activation tags for crop insertional mutagenesis. PLANT DIRECT 2021; 5:e00300. [PMID: 33506165 PMCID: PMC7814626 DOI: 10.1002/pld3.300] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Revised: 11/13/2020] [Accepted: 12/07/2020] [Indexed: 06/12/2023]
Abstract
Modern plant breeding increasingly relies on genomic information to guide crop improvement. Although some genes are characterized, additional tools are needed to effectively identify and characterize genes associated with crop traits. To address this need, the mPing element from rice was modified to serve as an activation tag to induce expression of nearby genes. Embedding promoter sequences in mPing resulted in a decrease in overall transposition rate; however, this effect was negated by using a hyperactive version of mPing called mmPing20. Transgenic soybean events carrying mPing-based activation tags and the appropriate transposase expression cassettes showed evidence of transposition. Expression analysis of a line that contained a heritable insertion of the mmPing20F activation tag indicated that the activation tag induced overexpression of the nearby soybean genes. This represents a significant advance in gene discovery technology as activation tags have the potential to induce more phenotypes than the original mPing element, improving the overall effectiveness of the mutagenesis system.
Collapse
Affiliation(s)
- Alexander Johnson
- Institute of Plant Breeding, Genetics & Genomics/Center for Applied Genetic TechnologiesUniversity of GeorgiaAthensGAUSA
| | - Edward Mcassey
- Institute of Plant Breeding, Genetics & Genomics/Center for Applied Genetic TechnologiesUniversity of GeorgiaAthensGAUSA
- Present address:
School of Life SciencesUniversity of Hawaiʻi at MānoaHonoluluHIUSA
| | - Stephanie Diaz
- Department of Biology and GeologyUniversity of South Carolina AikenAikenSCUSA
- Present address:
Department of BiochemistryPurdue UniversityWest LafayetteINUSA
| | - Jacob Reagin
- Department of Biology and GeologyUniversity of South Carolina AikenAikenSCUSA
| | - Priscilla S. Redd
- Department of Biology and GeologyUniversity of South Carolina AikenAikenSCUSA
| | - Daymond R. Parrilla
- Department of Biology and GeologyUniversity of South Carolina AikenAikenSCUSA
- Present address:
Department of Molecular and Comparative PathobiologyJohns Hopkins School of MedicineBaltimoreMDUSA
| | - Hanh Nguyen
- Department of Agronomy and Horticulture/Center for Plant Science InnovationUniversity of NebraskaLincolnNEUSA
| | - Adrian Stec
- Department of Agronomy and Plant GeneticsUniversity of MinnesotaSt. PaulMNUSA
| | - Lauren A. L. McDaniel
- Institute of Plant Breeding, Genetics & Genomics/Center for Applied Genetic TechnologiesUniversity of GeorgiaAthensGAUSA
| | - Thomas E. Clemente
- Department of Agronomy and Horticulture/Center for Plant Science InnovationUniversity of NebraskaLincolnNEUSA
| | - Robert M. Stupar
- Department of Agronomy and Plant GeneticsUniversity of MinnesotaSt. PaulMNUSA
| | - Wayne A. Parrott
- Institute of Plant Breeding, Genetics & Genomics/Center for Applied Genetic TechnologiesUniversity of GeorgiaAthensGAUSA
| | - C. Nathan Hancock
- Department of Biology and GeologyUniversity of South Carolina AikenAikenSCUSA
| |
Collapse
|
19
|
Dai D, Ma Z, Song R. Maize kernel development. MOLECULAR BREEDING : NEW STRATEGIES IN PLANT IMPROVEMENT 2021; 41:2. [PMID: 37309525 PMCID: PMC10231577 DOI: 10.1007/s11032-020-01195-9] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Accepted: 12/03/2020] [Indexed: 06/14/2023]
Abstract
Maize (Zea mays) is a leading cereal crop in the world. The maize kernel is the storage organ and the harvest portion of this crop and is closely related to its yield and quality. The development of maize kernel is initiated by the double fertilization event, leading to the formation of a diploid embryo and a triploid endosperm. The embryo and endosperm are then undergone independent developmental programs, resulting in a mature maize kernel which is comprised of a persistent endosperm, a large embryo, and a maternal pericarp. Due to the well-characterized morphogenesis and powerful genetics, maize kernel has long been an excellent model for the study of cereal kernel development. In recent years, with the release of the maize reference genome and the development of new genomic technologies, there has been an explosive expansion of new knowledge for maize kernel development. In this review, we overviewed recent progress in the study of maize kernel development, with an emphasis on genetic mapping of kernel traits, transcriptome analysis during kernel development, functional gene cloning of kernel mutants, and genetic engineering of kernel traits.
Collapse
Affiliation(s)
- Dawei Dai
- State Key Laboratory of Plant Physiology and Biochemistry, National Maize Improvement Center, Beijing Key Laboratory of Crop Genetic Improvement, Joint International Research Laboratory of Crop Molecular Breeding, College of Agronomy and Biotechnology, China Agricultural University, Beijing, 100193 China
- Shanghai Key Laboratory of Bio-Energy Crops, Plant Science Center, School of Life Sciences, Shanghai University, Shanghai, 200444 China
| | - Zeyang Ma
- State Key Laboratory of Plant Physiology and Biochemistry, National Maize Improvement Center, Beijing Key Laboratory of Crop Genetic Improvement, Joint International Research Laboratory of Crop Molecular Breeding, College of Agronomy and Biotechnology, China Agricultural University, Beijing, 100193 China
| | - Rentao Song
- State Key Laboratory of Plant Physiology and Biochemistry, National Maize Improvement Center, Beijing Key Laboratory of Crop Genetic Improvement, Joint International Research Laboratory of Crop Molecular Breeding, College of Agronomy and Biotechnology, China Agricultural University, Beijing, 100193 China
| |
Collapse
|
20
|
Su W, Zuo T, Peterson T. Ectopic Expression of a Maize Gene Is Induced by Composite Insertions Generated Through Alternative Transposition. Genetics 2020; 216:1039-1049. [PMID: 32988986 PMCID: PMC7768264 DOI: 10.1534/genetics.120.303592] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2020] [Accepted: 09/23/2020] [Indexed: 12/25/2022] Open
Abstract
Transposable elements (TEs) are DNA sequences that can mobilize and proliferate throughout eukaryotic genomes. Previous studies have shown that in plant genomes, TEs can influence gene expression in various ways, such as inserting in introns or exons to alter transcript structure and content, and providing novel promoters and regulatory elements to generate new regulatory patterns. Furthermore, TEs can also regulate gene expression at the epigenetic level by modifying chromatin structure, changing DNA methylation status, and generating small RNAs. In this study, we demonstrated that Ac/fractured Ac (fAc) TEs are able to induce ectopic gene expression by duplicating and shuffling enhancer elements. Ac/fAc elements belong to the hAT family of class II TEs. They can undergo standard transposition events, which involve the two termini of a single transposon, or alternative transposition events that involve the termini of two different nearby elements. Our previous studies have shown that alternative transposition can generate various genome rearrangements such as deletions, duplications, inversions, translocations, and composite insertions (CIs). We identified >50 independent cases of CIs generated by Ac/fAc alternative transposition and analyzed 10 of them in detail. We show that these CIs induced ectopic expression of the maize pericarp color 2 (p2) gene, which encodes a Myb-related protein. All the CIs analyzed contain sequences including a transcriptional enhancer derived from the nearby p1 gene, suggesting that the CI-induced activation of p2 is affected by mobilization of the p1 enhancer. This is further supported by analysis of a mutant in which the CI is excised and p2 expression is lost. These results show that alternative transposition events are not only able to induce genome rearrangements, but also generate CIs that can control gene expression.
Collapse
Affiliation(s)
- Weijia Su
- Department of Genetics, Development, and Cell Biology, Iowa State University, Ames, Iowa 50011-3260
| | - Tao Zuo
- Department of Genetics, Development, and Cell Biology, Iowa State University, Ames, Iowa 50011-3260
| | - Thomas Peterson
- Department of Genetics, Development, and Cell Biology, Iowa State University, Ames, Iowa 50011-3260
- Department of Agronomy, Iowa State University, Ames, Iowa 50011-3260
| |
Collapse
|
21
|
Wang D, Zhang J, Zuo T, Zhao M, Lisch D, Peterson T. Small RNA-Mediated De Novo Silencing of Ac/Ds Transposons Is Initiated by Alternative Transposition in Maize. Genetics 2020; 215:393-406. [PMID: 32317287 PMCID: PMC7268987 DOI: 10.1534/genetics.120.303264] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2019] [Accepted: 04/15/2020] [Indexed: 12/26/2022] Open
Abstract
Although transposable elements (TEs) comprise a major fraction of many higher eukaryotic genomes, most TEs are silenced by host defense mechanisms. The means by which otherwise active TEs are recognized and silenced remains poorly understood. Here we analyzed two independent cases of spontaneous silencing of the active maize Ac/Ds transposon system. This silencing is initiated by alternative transposition, a type of aberrant transposition event that engages the termini of two nearby separate TEs. Alternative transposition during DNA replication can generate Composite Insertions that contain inverted duplications of the transposon sequences. We show that the inverted duplications of two Composite Insertions are transcribed to produce double-stranded RNAs that trigger the production of two distinct classes of small interfering RNAs: a 24-nt class complementary to the TE terminal inverted repeats and noncoding subterminal regions, and a 21- to 22-nt class corresponding to the TE transcribed regions. Plants containing these small interfering RNA-generating Composite Insertions exhibit decreased levels of Ac transcript and heritable repression of Ac/Ds transposition. Further, we demonstrate that Composite Insertions can heritably silence otherwise active elements in trans This study documents the first case of transposon silencing induced by alternative transposition and may represent a general initiating mechanism for silencing of DNA transposons.
Collapse
Affiliation(s)
- Dafang Wang
- Division of Math and Sciences, Delta State University, Cleveland, Mississippi 38733-0001
| | - Jianbo Zhang
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, Iowa 50011-3260
| | - Tao Zuo
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, Iowa 50011-3260
| | - Meixia Zhao
- Department of Biology, Miami University, Oxford, Ohio 45056
| | - Damon Lisch
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, Indiana 47907
| | - Thomas Peterson
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, Iowa 50011-3260
- Department of Agronomy, Iowa State University, Ames, Iowa 50011-3260
| |
Collapse
|
22
|
Liu HJ, Jian L, Xu J, Zhang Q, Zhang M, Jin M, Peng Y, Yan J, Han B, Liu J, Gao F, Liu X, Huang L, Wei W, Ding Y, Yang X, Li Z, Zhang M, Sun J, Bai M, Song W, Chen H, Sun X, Li W, Lu Y, Liu Y, Zhao J, Qian Y, Jackson D, Fernie AR, Yan J. High-Throughput CRISPR/Cas9 Mutagenesis Streamlines Trait Gene Identification in Maize. THE PLANT CELL 2020; 32:1397-1413. [PMID: 32102844 PMCID: PMC7203946 DOI: 10.1105/tpc.19.00934] [Citation(s) in RCA: 118] [Impact Index Per Article: 29.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Revised: 02/06/2020] [Accepted: 02/21/2020] [Indexed: 05/19/2023]
Abstract
Maize (Zea mays) is one of the most important crops in the world. However, few agronomically important maize genes have been cloned and used for trait improvement, due to its complex genome and genetic architecture. Here, we integrated multiplexed CRISPR/Cas9-based high-throughput targeted mutagenesis with genetic mapping and genomic approaches to successfully target 743 candidate genes corresponding to traits relevant for agronomy and nutrition. After low-cost barcode-based deep sequencing, 412 edited sequences covering 118 genes were precisely identified from individuals showing clear phenotypic changes. The profiles of the associated gene-editing events were similar to those identified in human cell lines and consequently are predictable using an existing algorithm originally designed for human studies. We observed unexpected but frequent homology-directed repair through endogenous templates that was likely caused by spatial contact between distinct chromosomes. Based on the characterization and interpretation of gene function from several examples, we demonstrate that the integration of forward and reverse genetics via a targeted mutagenesis library promises rapid validation of important agronomic genes for crops with complex genomes. Beyond specific findings, this study also guides further optimization of high-throughput CRISPR experiments in plants.
Collapse
Affiliation(s)
- Hai-Jun Liu
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, China
| | - Liumei Jian
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, China
| | - Jieting Xu
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, China
- WIMI Biotechnology Co., Ltd., Changzhou 213000, China
| | - Qinghua Zhang
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, China
| | - Maolin Zhang
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, China
| | - Minliang Jin
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, China
| | - Yong Peng
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, China
| | - Jiali Yan
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, China
| | - Baozhu Han
- WIMI Biotechnology Co., Ltd., Changzhou 213000, China
| | - Jie Liu
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, China
| | - Fan Gao
- Xishuangbanna Institute of Agricultural Science, Yunnan Academy of Agricultural Sciences, Kunming 650205, China
| | - Xiangguo Liu
- Jilin Provincial Key Laboratory of Agricultural Biotechnology, Agro-Biotechnology Institute, Jilin Academy of Agricultural Sciences, Changchun 130033, China
| | - Lei Huang
- WIMI Biotechnology Co., Ltd., Changzhou 213000, China
| | - Wenjie Wei
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, China
| | - Yunxiu Ding
- Xishuangbanna Institute of Agricultural Science, Yunnan Academy of Agricultural Sciences, Kunming 650205, China
| | - Xiaofeng Yang
- WIMI Biotechnology Co., Ltd., Changzhou 213000, China
| | - Zhenxian Li
- Xishuangbanna Institute of Agricultural Science, Yunnan Academy of Agricultural Sciences, Kunming 650205, China
| | - Mingliang Zhang
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, China
| | - Jiamin Sun
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, China
| | - Minji Bai
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, China
| | - Wenhao Song
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, China
| | - Hanmo Chen
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, China
| | - Xi'ang Sun
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, China
| | - Wenqiang Li
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, China
| | - Yuming Lu
- Biogle Genome Editing Center, Changzhou 213125, China
| | - Ya Liu
- Beijing Key Laboratory of Maize DNA Fingerprinting and Molecular Breeding, Beijing Academy of Agriculture & Forestry Sciences, Beijing 100097, China
| | - Jiuran Zhao
- Beijing Key Laboratory of Maize DNA Fingerprinting and Molecular Breeding, Beijing Academy of Agriculture & Forestry Sciences, Beijing 100097, China
| | - Yangwen Qian
- WIMI Biotechnology Co., Ltd., Changzhou 213000, China
| | - David Jackson
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, China
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724
| | - Alisdair R Fernie
- Max Planck Institute of Molecular Plant Physiology, Potsdam-Golm 14476, Germany
| | - Jianbing Yan
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, China
| |
Collapse
|
23
|
Espinas NA, Tu LN, Furci L, Shimajiri Y, Harukawa Y, Miura S, Takuno S, Saze H. Transcriptional regulation of genes bearing intronic heterochromatin in the rice genome. PLoS Genet 2020; 16:e1008637. [PMID: 32187179 PMCID: PMC7145194 DOI: 10.1371/journal.pgen.1008637] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Revised: 04/09/2020] [Accepted: 01/28/2020] [Indexed: 11/18/2022] Open
Abstract
Intronic regions of eukaryotic genomes accumulate many Transposable Elements (TEs). Intronic TEs often trigger the formation of transcriptionally repressive heterochromatin, even within transcription-permissive chromatin environments. Although TE-bearing introns are widely observed in eukaryotic genomes, their epigenetic states, impacts on gene regulation and function, and their contributions to genetic diversity and evolution, remain poorly understood. In this study, we investigated the genome-wide distribution of intronic TEs and their epigenetic states in the Oryza sativa genome, where TEs comprise 35% of the genome. We found that over 10% of rice genes contain intronic heterochromatin, most of which are associated with TEs and repetitive sequences. These heterochromatic introns are longer and highly enriched in promoter-proximal positions. On the other hand, introns also accumulate hypomethylated short TEs. Genes with heterochromatic introns are implicated in various biological functions. Transcription of genes bearing intronic heterochromatin is regulated by an epigenetic mechanism involving the conserved factor OsIBM2, mutation of which results in severe developmental and reproductive defects. Furthermore, we found that heterochromatic introns evolve rapidly compared to non-heterochromatic introns. Our study demonstrates that heterochromatin is a common epigenetic feature associated with actively transcribed genes in the rice genome.
Collapse
Affiliation(s)
- Nino A. Espinas
- Plant Epigenetics Unit, Okinawa Institute of Science and Technology Graduate University, Onna-son, Okinawa, Japan
- Plant Immunity Research Group, RIKEN Center for Sustainable Resource Science (CSRS), Yokohama city, Kanagawa, Japan
| | - Le Ngoc Tu
- Plant Epigenetics Unit, Okinawa Institute of Science and Technology Graduate University, Onna-son, Okinawa, Japan
| | - Leonardo Furci
- Plant Epigenetics Unit, Okinawa Institute of Science and Technology Graduate University, Onna-son, Okinawa, Japan
| | - Yasuka Shimajiri
- Plant Epigenetics Unit, Okinawa Institute of Science and Technology Graduate University, Onna-son, Okinawa, Japan
- EditForce, Fukuoka, Japan
| | - Yoshiko Harukawa
- Plant Epigenetics Unit, Okinawa Institute of Science and Technology Graduate University, Onna-son, Okinawa, Japan
| | - Saori Miura
- Plant Epigenetics Unit, Okinawa Institute of Science and Technology Graduate University, Onna-son, Okinawa, Japan
| | - Shohei Takuno
- Department of Evolutionary Studies of Biosystems, SOKENDAI (The Graduate University for Advanced Studies), Hayama, Kanagawa, Japan
| | - Hidetoshi Saze
- Plant Epigenetics Unit, Okinawa Institute of Science and Technology Graduate University, Onna-son, Okinawa, Japan
| |
Collapse
|
24
|
Renny-Byfield S, Baumgarten A. Repetitive DNA content in the maize genome is uncoupled from population stratification at SNP loci. BMC Genomics 2020; 21:98. [PMID: 32000670 PMCID: PMC6993463 DOI: 10.1186/s12864-020-6517-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Accepted: 01/20/2020] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND Repetitive DNA is a major component of plant genomes and is thought to be a driver of evolutionary novelty. Describing variation in repeat content among individuals and between populations is key to elucidating the evolutionary significance of repetitive DNA. However, the cost of producing references genomes has limited large-scale intraspecific comparisons to a handful of model organisms where multiple reference genomes are available. RESULTS We examine repeat content variation in the genomes of 94 elite inbred maize lines using graph-based repeat clustering, a reference-free and rapid assay of repeat content. We examine population structure using genome-wide repeat profiles, and demonstrate the stiff-stalk and non-stiff-stalk heterotic populations are homogenous with regard to global repeat content. In contrast, and similar to previously reported results, the same individuals show clear differentiation, and aggregate into two populations when examining population structure using genome-wide SNPs. Additionally, we develop a novel kmer based technique to examine the chromosomal distribution of repeat clusters in silico and show a cluster dependent association with gene density. CONCLUSION Our results indicate global repeat content variation in the heterotic populations of maize has not diverged, and is uncoupled from population stratification at SNP loci. We show that repeat families exhibit divergent patterns with regard to chromosomal distribution, some repeat clusters accumulate in regions of high gene density, whereas others aggregate in regions of low gene density.
Collapse
|
25
|
Shamimuzzaman M, Gardiner JM, Walsh AT, Triant DA, Le Tourneau JJ, Tayal A, Unni DR, Nguyen HN, Portwood JL, Cannon EKS, Andorf CM, Elsik CG. MaizeMine: A Data Mining Warehouse for the Maize Genetics and Genomics Database. FRONTIERS IN PLANT SCIENCE 2020; 11:592730. [PMID: 33193550 PMCID: PMC7642280 DOI: 10.3389/fpls.2020.592730] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Accepted: 10/01/2020] [Indexed: 05/11/2023]
Abstract
MaizeMine is the data mining resource of the Maize Genetics and Genome Database (MaizeGDB; http://maizemine.maizegdb.org). It enables researchers to create and export customized annotation datasets that can be merged with their own research data for use in downstream analyses. MaizeMine uses the InterMine data warehousing system to integrate genomic sequences and gene annotations from the Zea mays B73 RefGen_v3 and B73 RefGen_v4 genome assemblies, Gene Ontology annotations, single nucleotide polymorphisms, protein annotations, homologs, pathways, and precomputed gene expression levels based on RNA-seq data from the Z. mays B73 Gene Expression Atlas. MaizeMine also provides database cross references between genes of alternative gene sets from Gramene and NCBI RefSeq. MaizeMine includes several search tools, including a keyword search, built-in template queries with intuitive search menus, and a QueryBuilder tool for creating custom queries. The Genomic Regions search tool executes queries based on lists of genome coordinates, and supports both the B73 RefGen_v3 and B73 RefGen_v4 assemblies. The List tool allows you to upload identifiers to create custom lists, perform set operations such as unions and intersections, and execute template queries with lists. When used with gene identifiers, the List tool automatically provides gene set enrichment for Gene Ontology (GO) and pathways, with a choice of statistical parameters and background gene sets. With the ability to save query outputs as lists that can be input to new queries, MaizeMine provides limitless possibilities for data integration and meta-analysis.
Collapse
Affiliation(s)
- Md Shamimuzzaman
- Division of Animal Sciences, University of Missouri, Columbia, MO, United States
| | - Jack M. Gardiner
- Division of Animal Sciences, University of Missouri, Columbia, MO, United States
| | - Amy T. Walsh
- Division of Animal Sciences, University of Missouri, Columbia, MO, United States
| | - Deborah A. Triant
- Division of Animal Sciences, University of Missouri, Columbia, MO, United States
| | | | - Aditi Tayal
- Division of Animal Sciences, University of Missouri, Columbia, MO, United States
| | - Deepak R. Unni
- Division of Environmental Genomics and Systems Biology, Lawrence Berkeley National Laboratory, Berkeley, CA, United States
| | - Hung N. Nguyen
- Division of Animal Sciences, University of Missouri, Columbia, MO, United States
| | - John L. Portwood
- USDA-ARS Corn Insects and Crop Genetics Research Unit, Iowa State University, Ames, IA, United States
| | - Ethalinda K. S. Cannon
- USDA-ARS Corn Insects and Crop Genetics Research Unit, Iowa State University, Ames, IA, United States
| | - Carson M. Andorf
- USDA-ARS Corn Insects and Crop Genetics Research Unit, Iowa State University, Ames, IA, United States
| | - Christine G. Elsik
- Division of Animal Sciences, University of Missouri, Columbia, MO, United States
- Division of Plant Sciences, University of Missouri, Columbia, MO, United States
- MU Institute for Data Science and Informatics, University of Missouri, Columbia, MO, United States
- *Correspondence: Christine G. Elsik,
| |
Collapse
|
26
|
Anderson SN, Stitzer MC, Brohammer AB, Zhou P, Noshay JM, O'Connor CH, Hirsch CD, Ross-Ibarra J, Hirsch CN, Springer NM. Transposable elements contribute to dynamic genome content in maize. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2019; 100:1052-1065. [PMID: 31381222 DOI: 10.1111/tpj.14489] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Revised: 07/15/2019] [Accepted: 07/26/2019] [Indexed: 05/05/2023]
Abstract
Transposable elements (TEs) are ubiquitous components of eukaryotic genomes and can create variation in genome organization and content. Most maize genomes are composed of TEs. We developed an approach to define shared and variable TE insertions across genome assemblies and applied this method to four maize genomes (B73, W22, Mo17 and PH207) with uniform structural annotations of TEs. Among these genomes we identified approximately 400 000 TEs that are polymorphic, encompassing 1.6 Gb of variable TE sequence. These polymorphic TEs include a combination of recent transposition events as well as deletions of older TEs. There are examples of polymorphic TEs within each of the superfamilies of TEs and they are found distributed across the genome, including in regions of recent shared ancestry among individuals. There are many examples of polymorphic TEs within or near maize genes. In addition, there are 2380 gene annotations in the B73 genome that are located within variable TEs, providing evidence for the role of TEs in contributing to the substantial differences in annotated gene content among these genotypes. TEs are highly variable in our survey of four temperate maize genomes, highlighting the major contribution of TEs in driving variation in genome organization and gene content. OPEN RESEARCH BADGES: This article has earned an Open Data Badge for making publicly available the digitally-shareable data necessary to reproduce the reported results. The data is available at https://github.com/SNAnderson/maizeTE_variation; https://mcstitzer.github.io/maize_TEs.
Collapse
Affiliation(s)
- Sarah N Anderson
- Department of Plant and Microbial Biology, University of Minnesota, St. Paul, MN, 55108, USA
| | - Michelle C Stitzer
- Department of Plant Sciences and Center for Population Biology, University of California, Davis, CA, 95616, USA
| | - Alex B Brohammer
- Department of Agronomy and Plant Genetics, University of Minnesota, St. Paul, MN, 55108, USA
| | - Peng Zhou
- Department of Plant and Microbial Biology, University of Minnesota, St. Paul, MN, 55108, USA
| | - Jaclyn M Noshay
- Department of Plant and Microbial Biology, University of Minnesota, St. Paul, MN, 55108, USA
| | - Christine H O'Connor
- Department of Agronomy and Plant Genetics, University of Minnesota, St. Paul, MN, 55108, USA
| | - Cory D Hirsch
- Department of Plant Pathology, University of Minnesota, St. Paul, MN, 55108, USA
| | - Jeffrey Ross-Ibarra
- Department of Plant Sciences and Center for Population Biology, University of California, Davis, CA, 95616, USA
- Genome Center, University of California, Davis, CA, 95616, USA
| | - Candice N Hirsch
- Department of Agronomy and Plant Genetics, University of Minnesota, St. Paul, MN, 55108, USA
| | - Nathan M Springer
- Department of Plant and Microbial Biology, University of Minnesota, St. Paul, MN, 55108, USA
| |
Collapse
|
27
|
Noshay JM, Anderson SN, Zhou P, Ji L, Ricci W, Lu Z, Stitzer MC, Crisp PA, Hirsch CN, Zhang X, Schmitz RJ, Springer NM. Monitoring the interplay between transposable element families and DNA methylation in maize. PLoS Genet 2019; 15:e1008291. [PMID: 31498837 PMCID: PMC6752859 DOI: 10.1371/journal.pgen.1008291] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Revised: 09/19/2019] [Accepted: 07/05/2019] [Indexed: 12/15/2022] Open
Abstract
DNA methylation and epigenetic silencing play important roles in the regulation of transposable elements (TEs) in many eukaryotic genomes. A majority of the maize genome is derived from TEs that can be classified into different orders and families based on their mechanism of transposition and sequence similarity, respectively. TEs themselves are highly methylated and it can be tempting to view them as a single uniform group. However, the analysis of DNA methylation profiles in flanking regions provides evidence for distinct groups of chromatin properties at different TE families. These differences among TE families are reproducible in different tissues and different inbred lines. TE families with varying levels of DNA methylation in flanking regions also show distinct patterns of chromatin accessibility and modifications within the TEs. The differences in the patterns of DNA methylation flanking TE families arise from a combination of non-random insertion preferences of TE families, changes in DNA methylation triggered by the insertion of the TE and subsequent selection pressure. A set of nearly 70,000 TE polymorphisms among four assembled maize genomes were used to monitor the level of DNA methylation at haplotypes with and without the TE insertions. In many cases, TE families with high levels of DNA methylation in flanking sequence are enriched for insertions into highly methylated regions. The majority of the >2,500 TE insertions into unmethylated regions result in changes in DNA methylation in haplotypes with the TE, suggesting the widespread potential for TE insertions to condition altered methylation in conserved regions of the genome. This study highlights the interplay between TEs and the methylome of a major crop species.
Collapse
Affiliation(s)
- Jaclyn M. Noshay
- Department of Plant and Microbial Biology, University of Minnesota, St. Paul MN, United States of America
| | - Sarah N. Anderson
- Department of Plant and Microbial Biology, University of Minnesota, St. Paul MN, United States of America
| | - Peng Zhou
- Department of Plant and Microbial Biology, University of Minnesota, St. Paul MN, United States of America
| | - Lexiang Ji
- Institute of Bioinformatics, University of Georgia, Athens GA, United States of America
| | - William Ricci
- Department of Plant Biology, University of Georgia, Athens GA, United States of America
| | - Zefu Lu
- Department of Genetics, University of Georgia, Athens GA, United States of America
| | - Michelle C. Stitzer
- Department of Plant Sciences, University of California Davis, Davis CA, United States of America
| | - Peter A. Crisp
- Department of Plant and Microbial Biology, University of Minnesota, St. Paul MN, United States of America
| | - Candice N. Hirsch
- Department of Agronomy and Plant Genetics, University of Minnesota, St. Paul MN, United States of America
| | - Xiaoyu Zhang
- Department of Plant Biology, University of Georgia, Athens GA, United States of America
| | - Robert J. Schmitz
- Department of Genetics, University of Georgia, Athens GA, United States of America
| | - Nathan M. Springer
- Department of Plant and Microbial Biology, University of Minnesota, St. Paul MN, United States of America
| |
Collapse
|
28
|
Borlini G, Rovera C, Landoni M, Cassani E, Pilu R. lpa1-5525: A New lpa1 Mutant Isolated in a Mutagenized Population by a Novel Non-Disrupting Screening Method. PLANTS 2019; 8:plants8070209. [PMID: 31284582 PMCID: PMC6681281 DOI: 10.3390/plants8070209] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/15/2019] [Revised: 06/29/2019] [Accepted: 07/04/2019] [Indexed: 11/16/2022]
Abstract
Phytic acid, or myo-inositol 1,2,3,4,5,6-hexakisphosphate, is the main storage form of phosphorus in plants. It is localized in seeds, deposited as mixed salts of mineral cations in protein storage vacuoles; during germination, it is hydrolyzed by phytases to make available P together with all the other cations needed for seed germination. When seeds are used as food or feed, phytic acid and the bound cations are poorly bioavailable for human and monogastric livestock due to their lack of phytase activity. Therefore, reducing the amount of phytic acid is one strategy in breeding programs aimed to improve the nutritional properties of major crops. In this work, we present data on the isolation of a new maize (Zea mays L.) low phytic acid 1 (lpa1) mutant allele obtained by transposon tagging mutagenesis with the Ac element. We describe the generation of the mutagenized population and the screening to isolate new lpa1 mutants. In particular, we developed a fast, cheap and non-disrupting screening method based on the different density of lpa1 seed compared to the wild type. This assay allowed the isolation of the lpa1-5525 mutant characterized by a new mutation in the lpa1 locus associated with a lower amount of phytic phosphorus in the seeds in comparison with the wild type.
Collapse
Affiliation(s)
- Giulia Borlini
- Department of Agricultural and Environmental Sciences-Production, Landscape, Agroenergy-Università degli Studi di Milano, Via Celoria 2, 20133 Milan, Italy
| | - Cesare Rovera
- Department of Agricultural and Environmental Sciences-Production, Landscape, Agroenergy-Università degli Studi di Milano, Via Celoria 2, 20133 Milan, Italy
| | - Michela Landoni
- Department of Biosciences-Università degli Studi di Milano, Via Celoria 26, 20133 Milan, Italy
| | - Elena Cassani
- Department of Agricultural and Environmental Sciences-Production, Landscape, Agroenergy-Università degli Studi di Milano, Via Celoria 2, 20133 Milan, Italy
| | - Roberto Pilu
- Department of Agricultural and Environmental Sciences-Production, Landscape, Agroenergy-Università degli Studi di Milano, Via Celoria 2, 20133 Milan, Italy.
| |
Collapse
|
29
|
Wu H, Xue X, Qin C, Xu Y, Guo Y, Li X, Lv W, Li Q, Mao C, Li L, Zhao S, Qi X, An H. An Efficient System for Ds Transposon Tagging in Brachypodium distachyon. PLANT PHYSIOLOGY 2019; 180:56-65. [PMID: 30867334 PMCID: PMC6501085 DOI: 10.1104/pp.18.00875] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Accepted: 03/02/2019] [Indexed: 06/09/2023]
Abstract
Transposon tagging is a powerful tool that has been widely applied in several species for insertional mutagenesis in plants. Several efforts have aimed to create transfer-DNA (T-DNA) insertional mutant populations in Brachypodium distachyon, a monocot plant used as a model system to study temperate cereals, but there has been a lack of research aimed at using transposon strategies. Here, we describe the application of a maize (Zea mays) Dissociation (Ds) transposon tagging system in B distachyon The 35S::AcTPase cassette and Ds element were constructed within the same T-DNA and transformed into B distachyon plants. The Ds element was readily transposed to other chromosomes or to the same chromosome under the function of Activator (Ac) transposase. Through homologous chromosome synapsis, recombination, and segregation, the Ds element separated from the Ac element. We selected stable Ds-only plants using G418 and GFP assays and analyzed 241 T0 lines, some of which were highly efficient at producing Ds-only progeny. Through thermal asymmetric interlaced PCR, we isolated 710 independent Ds flanking sequences from Ds-only plants. Furthermore, we identified a large collection of mutants with visible developmental phenotypes via this transposon tagging system. The system is relatively simple and rapid in comparison to traditional T-DNA insertion strategies, because once efficiency lines are obtained they can be reused to generate more lines from nontransposed plants without the use of time-consuming tissue culture steps.
Collapse
Affiliation(s)
- Hongyu Wu
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Shandong 271018, China
| | - Xiaodong Xue
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Shandong 271018, China
| | - Caihua Qin
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Shandong 271018, China
| | - Yi Xu
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Shandong 271018, China
| | - Yuyu Guo
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Shandong 271018, China
| | - Xiang Li
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Shandong 271018, China
| | - Wei Lv
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Shandong 271018, China
| | - Qinxia Li
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Shandong 271018, China
| | - Chuangxue Mao
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Shandong 271018, China
| | - Luzhao Li
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Shandong 271018, China
| | - Suzhen Zhao
- The Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
| | - Xiaoquan Qi
- The Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
| | - Hailong An
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Shandong 271018, China
| |
Collapse
|
30
|
Kudjordjie EN, Sapkota R, Steffensen SK, Fomsgaard IS, Nicolaisen M. Maize synthesized benzoxazinoids affect the host associated microbiome. MICROBIOME 2019; 7:59. [PMID: 30975184 DOI: 10.1186/s40168-019-0677-677] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Accepted: 03/28/2019] [Indexed: 05/28/2023]
Abstract
BACKGROUND Plants actively shape their associated microbial communities by synthesizing bio-active substances. Plant secondary metabolites are known for their signaling and plant defense functions, yet little is known about their overall effect on the plant microbiome. In this work, we studied the effects of benzoxazinoids (BXs), a group of secondary metabolites present in maize, on the host-associated microbial structure. Using BX knock-out mutants and their W22 parental lines, we employed 16S and ITS2 rRNA gene amplicon analysis to characterize the maize microbiome at early growth stages. RESULTS Rhizo-box experiment showed that BXs affected microbial communities not only in roots and shoots, but also in the rhizosphere. Fungal richness in roots was more affected by BXs than root bacterial richness. Maize genotype (BX mutants and their parental lines) as well as plant age explained both fungal and bacterial community structure. Genotypic effect on microbial communities was stronger in roots than in rhizosphere. Diverse, but specific, microbial taxa were affected by BX in both roots and shoots, for instance, many plant pathogens were negatively correlated to BX content. In addition, a co-occurrence analysis of the root microbiome revealed that BXs affected specific groups of the microbiome. CONCLUSIONS This study provides insights into the role of BXs for microbial community assembly in the rhizosphere and in roots and shoots. Coupling the quantification of BX metabolites with bacterial and fungal communities, we were able to suggest a gatekeeper role of BX by showing its correlation with specific microbial taxa and thus providing insights into effects on specific fungal and bacterial taxa in maize roots and shoots. Root microbial co-occurrence networks revealed that BXs affect specific microbial clusters.
Collapse
Affiliation(s)
- Enoch Narh Kudjordjie
- Faculty of Science and Technology, Department of Agroecology, Aarhus University, Forsøgsvej 1, 4200, Slagelse, Denmark
| | - Rumakanta Sapkota
- Faculty of Science and Technology, Department of Agroecology, Aarhus University, Forsøgsvej 1, 4200, Slagelse, Denmark
| | - Stine K Steffensen
- Faculty of Science and Technology, Department of Agroecology, Aarhus University, Forsøgsvej 1, 4200, Slagelse, Denmark
| | - Inge S Fomsgaard
- Faculty of Science and Technology, Department of Agroecology, Aarhus University, Forsøgsvej 1, 4200, Slagelse, Denmark
| | - Mogens Nicolaisen
- Faculty of Science and Technology, Department of Agroecology, Aarhus University, Forsøgsvej 1, 4200, Slagelse, Denmark.
| |
Collapse
|
31
|
Kudjordjie EN, Sapkota R, Steffensen SK, Fomsgaard IS, Nicolaisen M. Maize synthesized benzoxazinoids affect the host associated microbiome. MICROBIOME 2019; 7:59. [PMID: 30975184 PMCID: PMC6460791 DOI: 10.1186/s40168-019-0677-7] [Citation(s) in RCA: 135] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Accepted: 03/28/2019] [Indexed: 05/18/2023]
Abstract
BACKGROUND Plants actively shape their associated microbial communities by synthesizing bio-active substances. Plant secondary metabolites are known for their signaling and plant defense functions, yet little is known about their overall effect on the plant microbiome. In this work, we studied the effects of benzoxazinoids (BXs), a group of secondary metabolites present in maize, on the host-associated microbial structure. Using BX knock-out mutants and their W22 parental lines, we employed 16S and ITS2 rRNA gene amplicon analysis to characterize the maize microbiome at early growth stages. RESULTS Rhizo-box experiment showed that BXs affected microbial communities not only in roots and shoots, but also in the rhizosphere. Fungal richness in roots was more affected by BXs than root bacterial richness. Maize genotype (BX mutants and their parental lines) as well as plant age explained both fungal and bacterial community structure. Genotypic effect on microbial communities was stronger in roots than in rhizosphere. Diverse, but specific, microbial taxa were affected by BX in both roots and shoots, for instance, many plant pathogens were negatively correlated to BX content. In addition, a co-occurrence analysis of the root microbiome revealed that BXs affected specific groups of the microbiome. CONCLUSIONS This study provides insights into the role of BXs for microbial community assembly in the rhizosphere and in roots and shoots. Coupling the quantification of BX metabolites with bacterial and fungal communities, we were able to suggest a gatekeeper role of BX by showing its correlation with specific microbial taxa and thus providing insights into effects on specific fungal and bacterial taxa in maize roots and shoots. Root microbial co-occurrence networks revealed that BXs affect specific microbial clusters.
Collapse
Affiliation(s)
- Enoch Narh Kudjordjie
- Faculty of Science and Technology, Department of Agroecology, Aarhus University, Forsøgsvej 1, 4200 Slagelse, Denmark
| | - Rumakanta Sapkota
- Faculty of Science and Technology, Department of Agroecology, Aarhus University, Forsøgsvej 1, 4200 Slagelse, Denmark
| | - Stine K. Steffensen
- Faculty of Science and Technology, Department of Agroecology, Aarhus University, Forsøgsvej 1, 4200 Slagelse, Denmark
| | - Inge S. Fomsgaard
- Faculty of Science and Technology, Department of Agroecology, Aarhus University, Forsøgsvej 1, 4200 Slagelse, Denmark
| | - Mogens Nicolaisen
- Faculty of Science and Technology, Department of Agroecology, Aarhus University, Forsøgsvej 1, 4200 Slagelse, Denmark
| |
Collapse
|
32
|
Doll NM, Gilles LM, Gérentes MF, Richard C, Just J, Fierlej Y, Borrelli VMG, Gendrot G, Ingram GC, Rogowsky PM, Widiez T. Single and multiple gene knockouts by CRISPR-Cas9 in maize. PLANT CELL REPORTS 2019; 38:487-501. [PMID: 30684023 DOI: 10.1007/s00299-019-02378-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Accepted: 01/07/2019] [Indexed: 05/20/2023]
Abstract
The analysis of 93 mutant alleles in 18 genes demonstrated that CRISPR-Cas9 is a robust tool for targeted mutagenesis in maize, permitting efficient generation of single and multiple knockouts. CRISPR-Cas9 technology is a simple and efficient tool for targeted mutagenesis of the genome. It has been implemented in many plant species, including crops such as maize. Here we report single- and multiple-gene mutagenesis via stably transformed maize plants. Two different CRISPR-Cas9 vectors were used allowing the expression of multiple guide RNAs and different strategies to knockout either independent or paralogous genes. A total of 12 plasmids, representing 28 different single guide RNAs (sgRNAs), were generated to target 20 genes. For 18 of these genes, at least one mutant allele was obtained, while two genes were recalcitrant to sequence editing. 19% (16/83) of mutant plants showed biallelic mutations. Small insertions or deletions of less than ten nucleotides were most frequently observed, regardless of whether the gene was targeted by one or more sgRNAs. Deletions of defined regions located between the target sites of two guide RNAs were also reported although the exact deletion size was variable. Double and triple mutants were created in a single step, which is especially valuable for functional analysis of genes with strong genetic linkage. Off-target effects were theoretically limited due to rigorous sgRNA design and random experimental checks at three potential off-target sites did not reveal any editing. Sanger chromatograms allowed to unambiguously class the primary transformants; the majority (85%) were fully edited plants transmitting systematically all detected mutations to the next generation, generally following Mendelian segregation.
Collapse
Affiliation(s)
- Nicolas M Doll
- Laboratoire Reproduction et Développement des Plantes, Univ Lyon, ENS de Lyon, UCB Lyon 1, CNRS, INRA, 69342, Lyon, France
| | - Laurine M Gilles
- Laboratoire Reproduction et Développement des Plantes, Univ Lyon, ENS de Lyon, UCB Lyon 1, CNRS, INRA, 69342, Lyon, France
- Limagrain Europe SAS, Research Centre, 63720, Chappes, France
| | - Marie-France Gérentes
- Laboratoire Reproduction et Développement des Plantes, Univ Lyon, ENS de Lyon, UCB Lyon 1, CNRS, INRA, 69342, Lyon, France
| | - Christelle Richard
- Laboratoire Reproduction et Développement des Plantes, Univ Lyon, ENS de Lyon, UCB Lyon 1, CNRS, INRA, 69342, Lyon, France
| | - Jeremy Just
- Laboratoire Reproduction et Développement des Plantes, Univ Lyon, ENS de Lyon, UCB Lyon 1, CNRS, INRA, 69342, Lyon, France
| | - Yannick Fierlej
- Laboratoire Reproduction et Développement des Plantes, Univ Lyon, ENS de Lyon, UCB Lyon 1, CNRS, INRA, 69342, Lyon, France
- MAS Seeds, Route de Saint-Sever, 40280, Haut-Mauco, France
| | - Virginia M G Borrelli
- Department of Sustainable Crop Production, Università Cattolica del Sacro Cuore, Piacenza, Italy
| | - Ghislaine Gendrot
- Laboratoire Reproduction et Développement des Plantes, Univ Lyon, ENS de Lyon, UCB Lyon 1, CNRS, INRA, 69342, Lyon, France
| | - Gwyneth C Ingram
- Laboratoire Reproduction et Développement des Plantes, Univ Lyon, ENS de Lyon, UCB Lyon 1, CNRS, INRA, 69342, Lyon, France
| | - Peter M Rogowsky
- Laboratoire Reproduction et Développement des Plantes, Univ Lyon, ENS de Lyon, UCB Lyon 1, CNRS, INRA, 69342, Lyon, France
| | - Thomas Widiez
- Laboratoire Reproduction et Développement des Plantes, Univ Lyon, ENS de Lyon, UCB Lyon 1, CNRS, INRA, 69342, Lyon, France.
| |
Collapse
|
33
|
Yao H, Skirpan A, Wardell B, Matthes MS, Best NB, McCubbin T, Durbak A, Smith T, Malcomber S, McSteen P. The barren stalk2 Gene Is Required for Axillary Meristem Development in Maize. MOLECULAR PLANT 2019; 12:374-389. [PMID: 30690173 DOI: 10.1016/j.molp.2018.12.024] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Revised: 12/08/2018] [Accepted: 12/21/2018] [Indexed: 06/09/2023]
Abstract
The diversity of plant architecture is determined by axillary meristems (AMs). AMs are produced from small groups of stem cells in the axils of leaf primordia and generate vegetative branches and reproductive inflorescences. Previous studies identified genes critical for AM development that function in auxin biosynthesis, transport, and signaling. barren stalk1 (ba1), a basic helix-loop-helix transcription factor, acts downstream of auxin to control AM formation. Here, we report the cloning and characterization of barren stalk2 (ba2), a mutant that fails to produce ears and has fewer branches and spikelets in the tassel, indicating that ba2 functions in reproductive AM development. Furthermore, the ba2 mutation suppresses tiller growth in the teosinte branched1 mutant, indicating that ba2 also plays an essential role in vegetative AM development. The ba2 gene encodes a protein that co-localizes and heterodimerizes with BA1 in the nucleus. Characterization of the genetic interaction between ba2 and ba1 demonstrates that ba1 shows a gene dosage effect in ba2 mutants, providing further evidence that BA1 and BA2 act together in the same pathway. Characterization of the molecular and genetic interaction between ba2 and additional genes required for the regulation of ba1 further supports this finding. The ba1 and ba2 genes are orthologs of rice genes, LAX PANICLE1 (LAX1) and LAX2, respectively, hence providing insights into pathways controlling AMs development in grasses.
Collapse
Affiliation(s)
- Hong Yao
- Division of Biological Sciences, Interdisciplinary Plant Group, Bond Life Sciences Center, University of Missouri, Columbia, MO 65211, USA
| | - Andrea Skirpan
- Department of Biology, Penn State University, University Park, PA 16802, USA
| | - Brian Wardell
- Department of Biological Sciences, California State University, Long Beach, CA 90840, USA
| | - Michaela S Matthes
- Division of Biological Sciences, Interdisciplinary Plant Group, Bond Life Sciences Center, University of Missouri, Columbia, MO 65211, USA
| | - Norman B Best
- Division of Biological Sciences, Interdisciplinary Plant Group, Bond Life Sciences Center, University of Missouri, Columbia, MO 65211, USA
| | - Tyler McCubbin
- Division of Biological Sciences, Interdisciplinary Plant Group, Columbia, MO 65211, USA
| | - Amanda Durbak
- Division of Biological Sciences, Interdisciplinary Plant Group, Bond Life Sciences Center, University of Missouri, Columbia, MO 65211, USA
| | - Taylor Smith
- Division of Biological Sciences, Interdisciplinary Plant Group, Bond Life Sciences Center, University of Missouri, Columbia, MO 65211, USA
| | - Simon Malcomber
- Department of Biological Sciences, California State University, Long Beach, CA 90840, USA
| | - Paula McSteen
- Division of Biological Sciences, Interdisciplinary Plant Group, Bond Life Sciences Center, University of Missouri, Columbia, MO 65211, USA.
| |
Collapse
|
34
|
Bettgenhaeuser J, Krattinger SG. Rapid gene cloning in cereals. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2019; 132:699-711. [PMID: 30341495 DOI: 10.1007/s00122-018-3210-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Accepted: 10/12/2018] [Indexed: 05/03/2023]
Abstract
The large and complex genomes of many cereals hindered cloning efforts in the past. Advances in genomics now allow the rapid cloning of genes from humanity's most valuable crops. The past two decades were characterized by a genomics revolution that entailed profound changes to crop research, plant breeding, and agriculture. Today, high-quality reference sequences are available for all major cereal crop species. Large resequencing and pan-genome projects start to reveal a more comprehensive picture of the genetic makeup and the diversity among domesticated cereals and their wild relatives. These technological advancements will have a dramatic effect on dissecting genotype-phenotype associations and on gene cloning. In this review, we will highlight the status of the genomic resources available for various cereal crops and we will discuss their implications for gene cloning. A particular focus will be given to the cereal species barley and wheat, which are characterized by very large and complex genomes that have been inaccessible to rapid gene cloning until recently. With the advancements in genomics and the development of several rapid gene-cloning methods, it has now become feasible to tackle the cloning of most agriculturally important genes, even in wheat and barley.
Collapse
Affiliation(s)
- Jan Bettgenhaeuser
- Biological and Environmental Science and Engineering Division (BESE), King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia
| | - Simon G Krattinger
- Biological and Environmental Science and Engineering Division (BESE), King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia.
| |
Collapse
|
35
|
Andorf C, Beavis WD, Hufford M, Smith S, Suza WP, Wang K, Woodhouse M, Yu J, Lübberstedt T. Technological advances in maize breeding: past, present and future. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2019; 132:817-849. [PMID: 30798332 DOI: 10.1007/s00122-019-03306-3] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Accepted: 02/05/2019] [Indexed: 05/18/2023]
Abstract
Maize has for many decades been both one of the most important crops worldwide and one of the primary genetic model organisms. More recently, maize breeding has been impacted by rapid technological advances in sequencing and genotyping technology, transformation including genome editing, doubled haploid technology, parallelled by progress in data sciences and the development of novel breeding approaches utilizing genomic information. Herein, we report on past, current and future developments relevant for maize breeding with regard to (1) genome analysis, (2) germplasm diversity characterization and utilization, (3) manipulation of genetic diversity by transformation and genome editing, (4) inbred line development and hybrid seed production, (5) understanding and prediction of hybrid performance, (6) breeding methodology and (7) synthesis of opportunities and challenges for future maize breeding.
Collapse
Affiliation(s)
| | - William D Beavis
- Department of Agronomy, Iowa State University, Agronomy Hall, Ames, IA, 50011-1010, USA
| | - Matthew Hufford
- Department of Ecology, Evolution and Organismal Biology, Iowa State University, Ames, IA, 50011-1010, USA
| | - Stephen Smith
- Department of Agronomy, Iowa State University, Agronomy Hall, Ames, IA, 50011-1010, USA
| | - Walter P Suza
- Department of Agronomy, Iowa State University, Agronomy Hall, Ames, IA, 50011-1010, USA
| | - Kan Wang
- Department of Agronomy, Iowa State University, Agronomy Hall, Ames, IA, 50011-1010, USA
| | | | - Jianming Yu
- Department of Agronomy, Iowa State University, Agronomy Hall, Ames, IA, 50011-1010, USA
| | - Thomas Lübberstedt
- Department of Agronomy, Iowa State University, Agronomy Hall, Ames, IA, 50011-1010, USA.
| |
Collapse
|
36
|
Yang P, Praz C, Li B, Singla J, Robert CAM, Kessel B, Scheuermann D, Lüthi L, Ouzunova M, Erb M, Krattinger SG, Keller B. Fungal resistance mediated by maize wall-associated kinase ZmWAK-RLK1 correlates with reduced benzoxazinoid content. THE NEW PHYTOLOGIST 2019; 221:976-987. [PMID: 30178602 DOI: 10.1111/nph.15419] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Accepted: 07/30/2018] [Indexed: 05/20/2023]
Abstract
Wall-associated kinases (WAKs) have recently been identified as major components of fungal and bacterial disease resistance in several cereal crop species. However, the molecular mechanisms of WAK-mediated resistance remain largely unknown. Here, we investigated the function of the maize gene ZmWAK-RLK1 (Htn1) that confers quantitative resistance to northern corn leaf blight (NCLB) caused by the hemibiotrophic fungal pathogen Exserohilum turcicum. ZmWAK-RLK1 was found to localize to the plasma membrane and its presence resulted in a modification of the infection process by reducing pathogen penetration into host tissues. A large-scale transcriptome analysis of near-isogenic lines (NILs) differing for ZmWAK-RLK1 revealed that several differentially expressed genes are involved in the biosynthesis of the secondary metabolites benzoxazinoids (BXs). The contents of several BXs including DIM2 BOA-Glc were significantly lower when ZmWAK-RLK1 is present. DIM2 BOA-Glc concentration was significantly elevated in ZmWAK-RLK1 mutants with compromised NCLB resistance. Maize mutants that were affected in overall BXs biosynthesis or content of DIM2 BOA-Glc showed increased NCLB resistance. We conclude that Htn1-mediated NCLB resistance is associated with a reduction of BX secondary metabolites. These findings suggest a link between WAK-mediated quantitative disease resistance and changes in biochemical fluxes starting with indole-3-glycerol phosphate.
Collapse
Affiliation(s)
- Ping Yang
- Department of Plant and Microbial Biology, University of Zurich, Zollikerstrasse 107, CH-8008, Zurich, Switzerland
- Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, 100081, Beijing, China
| | - Coraline Praz
- Department of Plant and Microbial Biology, University of Zurich, Zollikerstrasse 107, CH-8008, Zurich, Switzerland
| | - Beibei Li
- Institute of Plant Sciences, University of Bern, CH-3013, Bern, Switzerland
| | - Jyoti Singla
- Department of Plant and Microbial Biology, University of Zurich, Zollikerstrasse 107, CH-8008, Zurich, Switzerland
| | | | | | | | - Linda Lüthi
- Department of Plant and Microbial Biology, University of Zurich, Zollikerstrasse 107, CH-8008, Zurich, Switzerland
| | | | - Matthias Erb
- Institute of Plant Sciences, University of Bern, CH-3013, Bern, Switzerland
| | - Simon G Krattinger
- Department of Plant and Microbial Biology, University of Zurich, Zollikerstrasse 107, CH-8008, Zurich, Switzerland
- King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Beat Keller
- Department of Plant and Microbial Biology, University of Zurich, Zollikerstrasse 107, CH-8008, Zurich, Switzerland
| |
Collapse
|
37
|
Gene Essentiality Analyzed by In Vivo Transposon Mutagenesis and Machine Learning in a Stable Haploid Isolate of Candida albicans. mBio 2018; 9:mBio.02048-18. [PMID: 30377286 PMCID: PMC6212825 DOI: 10.1128/mbio.02048-18] [Citation(s) in RCA: 83] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Comprehensive understanding of an organism requires that we understand the contributions of most, if not all, of its genes. Classical genetic approaches to this issue have involved systematic deletion of each gene in the genome, with comprehensive sets of mutants available only for very-well-studied model organisms. We took a different approach, harnessing the power of in vivo transposition coupled with deep sequencing to identify >500,000 different mutations, one per cell, in the prevalent human fungal pathogen Candida albicans and to map their positions across the genome. The transposition approach is efficient and less labor-intensive than classic approaches. Here, we describe the production and analysis (aided by machine learning) of a large collection of mutants and the comprehensive identification of 1,610 C. albicans genes that are essential for growth under standard laboratory conditions. Among these C. albicans essential genes, we identify those that are also essential in two distantly related model yeasts as well as those that are conserved in all four major human fungal pathogens and that are not conserved in the human genome. This list of genes with functions important for the survival of the pathogen provides a good starting point for the development of new antifungal drugs, which are greatly needed because of the emergence of fungal pathogens with elevated resistance and/or tolerance of the currently limited set of available antifungal drugs. Knowing the full set of essential genes for a given organism provides important information about ways to promote, and to limit, its growth and survival. For many non-model organisms, the lack of a stable haploid state and low transformation efficiencies impede the use of conventional approaches to generate a genome-wide comprehensive set of mutant strains and the identification of the genes essential for growth. Here we report on the isolation and utilization of a highly stable haploid derivative of the human pathogenic fungus Candida albicans, together with a modified heterologous transposon and machine learning (ML) analysis method, to predict the degree to which all of the open reading frames are required for growth under standard laboratory conditions. We identified 1,610 C. albicans essential genes, including 1,195 with high “essentiality confidence” scores, thereby increasing the number of essential genes (currently 66 in the Candida Genome Database) by >20-fold and providing an unbiased approach to determine the degree of confidence in the determination of essentiality. Among the genes essential in C. albicans were 602 genes also essential in the model budding and fission yeasts analyzed by both deletion and transposon mutagenesis. We also identified essential genes conserved among the four major human pathogens C. albicans, Aspergillus fumigatus, Cryptococcus neoformans, and Histoplasma capsulatum and highlight those that lack homologs in humans and that thus could serve as potential targets for the design of antifungal therapies.
Collapse
|
38
|
The maize W22 genome provides a foundation for functional genomics and transposon biology. Nat Genet 2018; 50:1282-1288. [PMID: 30061736 DOI: 10.1038/s41588-018-0158-0] [Citation(s) in RCA: 114] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Accepted: 05/17/2018] [Indexed: 11/08/2022]
Abstract
The maize W22 inbred has served as a platform for maize genetics since the mid twentieth century. To streamline maize genome analyses, we have sequenced and de novo assembled a W22 reference genome using short-read sequencing technologies. We show that significant structural heterogeneity exists in comparison to the B73 reference genome at multiple scales, from transposon composition and copy number variation to single-nucleotide polymorphisms. The generation of this reference genome enables accurate placement of thousands of Mutator (Mu) and Dissociation (Ds) transposable element insertions for reverse and forward genetics studies. Annotation of the genome has been achieved using RNA-seq analysis, differential nuclease sensitivity profiling and bisulfite sequencing to map open reading frames, open chromatin sites and DNA methylation profiles, respectively. Collectively, the resources developed here integrate W22 as a community reference genome for functional genomics and provide a foundation for the maize pan-genome.
Collapse
|
39
|
Mielich K, Shtifman-Segal E, Golz JC, Zeng G, Wang Y, Berman J, Kunze R. Maize Transposable Elements Ac/ Ds as Insertion Mutagenesis Tools in Candida albicans. G3 (BETHESDA, MD.) 2018; 8:1139-1145. [PMID: 29378819 PMCID: PMC5873905 DOI: 10.1534/g3.117.300388] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Accepted: 01/26/2018] [Indexed: 12/23/2022]
Abstract
In nonmodel systems, genetic research is often limited by the lack of techniques for the generation and identification of gene mutations. One approach to overcome this bottleneck is the application of transposons for gene tagging. We have established a two-element transposon tagging system, based on the transposable elements Activator (Ac)/Dissociation (Ds) from maize, for in vivo insertion mutagenesis in the fungal human pathogen Candida albicans A nonautonomous Ds transposon carrying a selectable marker was constructed into the ADE2 promoter on chromosome 3 and a codon usage-adapted Ac transposase gene was inserted into the neutral NEUT5L locus on chromosome 5. In C. albicans cells expressing the transposase, the Ds element efficiently excised and reintegrated elsewhere in the genome, which makes the Ac/Ds transposons promising tools for saturating insertion mutagenesis in clinical strains of C. albicans.
Collapse
Affiliation(s)
- Kevin Mielich
- Institute of Biology, Dahlem Centre of Plant Sciences, Free University pf Berlin, 14195, Germany
| | - Ella Shtifman-Segal
- Department of Molecular Microbiology and Biotechnology, George Wise Faculty of Life Sciences, Tel Aviv University, Ramat Aviv 69978, Israel
| | - Julia C Golz
- Institute of Biology, Dahlem Centre of Plant Sciences, Free University pf Berlin, 14195, Germany
| | - Guisheng Zeng
- Institute of Molecular and Cell Biology, Agency for Science, Technology and Research, 138673, Singapore
| | - Yue Wang
- Institute of Molecular and Cell Biology, Agency for Science, Technology and Research, 138673, Singapore
| | - Judith Berman
- Department of Molecular Microbiology and Biotechnology, George Wise Faculty of Life Sciences, Tel Aviv University, Ramat Aviv 69978, Israel
| | - Reinhard Kunze
- Institute of Biology, Dahlem Centre of Plant Sciences, Free University pf Berlin, 14195, Germany
| |
Collapse
|
40
|
Lu X, Liu J, Ren W, Yang Q, Chai Z, Chen R, Wang L, Zhao J, Lang Z, Wang H, Fan Y, Zhao J, Zhang C. Gene-Indexed Mutations in Maize. MOLECULAR PLANT 2018; 11:496-504. [PMID: 29223623 DOI: 10.1016/j.molp.2017.11.013] [Citation(s) in RCA: 127] [Impact Index Per Article: 21.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Revised: 11/20/2017] [Accepted: 11/28/2017] [Indexed: 05/19/2023]
Abstract
The availability of the B73 inbred reference genome sets the stage for high-throughput functional characterization of maize genes on a whole-genome scale. Among the 39 324 protein-coding genes predicted, the vast majority are untapped due to the lack of suitable high-throughput reverse genetic resources. We have generated a gene-indexed maize mutant collection through ethyl methanesulfonate mutagenesis and detected the mutations by combining exome capture and next-generation sequencing. A total of 1086 mutated M1 plants were sequenced, and 195 268 CG>TA-type point mutations, including stop gain/loss, missplice, start gain/loss, and various non-synonymous protein mutations as well as 4610 InDel mutations, were identified. These mutations were distributed on 32 069 genes, representing 82% of the predicted protein-coding genes in the maize genome. We detected an average of 180 mutations per mutant line and 6.1 mutations per gene. As many as 27 214 mutations of start codons, stop codons, or missplice sites were identified in 14 101 genes, among which 6232 individual genes harbored more than two such mutations. Application of this mutant collection is exemplified by the identification of the ent-kaurene synthase gene, which encodes a key enzyme in the gibberellin biosynthesis pathway. This gene-indexed genome-wide mutation collection provides an important resource for functional analysis of maize genes and may bring desirable allelic variants for genetic breeding in maize.
Collapse
Affiliation(s)
- Xiaoduo Lu
- Institute of Molecular Breeding for Maize, Qilu Normal University, Jinan 250200, China; Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Jisheng Liu
- Institute of Molecular Breeding for Maize, Qilu Normal University, Jinan 250200, China
| | - Wen Ren
- Maize Research Center, Beijing Academy of Agriculture & Forestry Sciences, Beijing Key Laboratory of Maize DNA Fingerprinting and Molecular Breeding, Beijing 100097, China
| | - Qun Yang
- Institute of Molecular Breeding for Maize, Qilu Normal University, Jinan 250200, China
| | - Zhenguang Chai
- Institute of Molecular Breeding for Maize, Qilu Normal University, Jinan 250200, China
| | - Rumei Chen
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Lei Wang
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Jun Zhao
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Zhihong Lang
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Haiyang Wang
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Yunliu Fan
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Jiuran Zhao
- Maize Research Center, Beijing Academy of Agriculture & Forestry Sciences, Beijing Key Laboratory of Maize DNA Fingerprinting and Molecular Breeding, Beijing 100097, China.
| | - Chunyi Zhang
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
| |
Collapse
|
41
|
Woldemariam MG, Ahern K, Jander G, Tzin V. A role for 9-lipoxygenases in maize defense against insect herbivory. PLANT SIGNALING & BEHAVIOR 2018; 13:e1422462. [PMID: 29293391 PMCID: PMC5790410 DOI: 10.1080/15592324.2017.1422462] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Revised: 12/06/2017] [Accepted: 12/08/2017] [Indexed: 05/22/2023]
Abstract
Feeding by Spodoptera exigua (beet armyworm) larvae on Zea mays (maize) induces expression of 9-lipoxygenases to a greater extent than 13-lipoxygenases. Whereas 13-lipoxygenases have an established role in the synthesis of jasmonates that serve as defense signaling molecules in many plant species, relatively little is known about the role of 9-lipoxygenases in herbivore defense. Phylogenetic analysis of lipoxygenases from maize inbred lines B73 and W22 shows that, although most Lox genes are present in both lines, Lox12, a 9-lipoxygenase that has been implicated in fungal defense, is truncated and unlikely to encode a functional protein in W22. Two independent Mutator transposon insertions in another 9-lipoxygenase, Lox4, caused improved S. exigua growth on the mutant lines relative to wildtype W22. This observation suggests a function in herbivore defense for metabolic products downstream of maize Lox4, either through direct toxicity or a perhaps an as yet unknown signaling function.
Collapse
Affiliation(s)
- Melkamu G. Woldemariam
- Biology Department, School of Science, The College of New Jersey, Ewing Township, NJ, USA
| | | | | | - Vered Tzin
- Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede Boqer, Israel
| |
Collapse
|
42
|
Jia S, Li A, Zhang C, Holding D. Deletion Mutagenesis and Identification of Causative Mutations in Maize. Methods Mol Biol 2018; 1676:97-108. [PMID: 28986905 DOI: 10.1007/978-1-4939-7315-6_5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
We describe a method for gamma-irradiation of mature maize seeds to generate mutants with opaque endosperm and reduced kernel fill phenotypes. We also describe methods for mapping mutants and identifying causal gene mutations. Using this method, a population of 1788M2 families and 47 Mo17 × F2s showing stable, segregating, and viable kernel phenotypes was developed. For molecular characterization of the mutants, we utilized a novel functional genomics platform that combines separate Bulked Segregant RNA and exome sequencing data sets (BSREx-seq) to map causative mutations and identify candidate genes within mapping intervals. We also describe the use of exome capture sequencing of F2 mutant and normal pools to perform mapping and candidate gene identification without the need for separate RNA-seq (BSEx-seq). To exemplify the utility of the deletion mutants for functional genomics and provide proof-of-concept for the bioinformatics platform, we summarize the identification of the causative deletion in two mutants. Mutant 937, which was characterized by BSREx-seq, harbors a 6203-bp in-frame deletion covering six exons within the Opaque-1 gene on chromosome 4. Preliminary investigation of opaque mutant 1486 with BSEx-seq shows a tight mapping interval and associated deletion on chromosome 10.
Collapse
Affiliation(s)
- Shangang Jia
- Department of Agronomy and Horticulture, Center for Plant Science Innovation, Beadle Center for Biotechnology, University of Nebraska - Lincoln, 1901 Vine Street, P.O. Box 880665, Lincoln, NE, 68588-0665, USA
| | - Aixia Li
- Department of Agronomy and Horticulture, Center for Plant Science Innovation, Beadle Center for Biotechnology, University of Nebraska - Lincoln, 1901 Vine Street, P.O. Box 880665, Lincoln, NE, 68588-0665, USA
| | - Chi Zhang
- School of Biological Sciences, Center for Plant Science and Innovation, Beadle Center for Biotechnology, University of Nebraska - Lincoln, 1901 Vine Street, P.O. Box 880665, Lincoln, NE, 68588-0665, USA
| | - David Holding
- Department of Agronomy and Horticulture, Center for Plant Science Innovation, Beadle Center for Biotechnology, University of Nebraska - Lincoln, 1901 Vine Street, P.O. Box 880665, Lincoln, NE, 68588-0665, USA.
| |
Collapse
|
43
|
Tzin V, Hojo Y, Strickler SR, Bartsch LJ, Archer CM, Ahern KR, Zhou S, Christensen SA, Galis I, Mueller LA, Jander G. Rapid defense responses in maize leaves induced by Spodoptera exigua caterpillar feeding. JOURNAL OF EXPERIMENTAL BOTANY 2017; 68:4709-4723. [PMID: 28981781 PMCID: PMC5853842 DOI: 10.1093/jxb/erx274] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2017] [Accepted: 07/13/2017] [Indexed: 05/20/2023]
Abstract
Insects such as the beet armyworm (Spodoptera exigua) cause extensive damage to maize (Zea mays). Maize plants respond by triggering defense signaling, changes in gene expression, and biosynthesis of specialized metabolites. Leaves of maize inbred line B73, which has an available genome sequence, were infested with S. exigua for 1 to 24 h, followed by comparisons of the transcript and metabolite profiles with those of uninfested controls. The most extensive gene expression responses occurred rapidly, within 4-6 h after caterpillar infestation. However, both gene expression and metabolite profiles were altered within 1 h and continued to change during the entire 24 h experiment. The defensive functions of three caterpillar-induced genes were examined using available Dissociation transposon insertions in maize inbred line W22. Whereas mutations in the benzoxazinoid biosynthesis pathway (Bx1 and Bx2) significantly improved caterpillar growth, the knockout of a 13-lipoxygenase (Lox8) involved in jasmonic acid biosynthesis did not. Interestingly, 9-lipoxygenases, which lead to the production of maize death acids, were more strongly induced by caterpillar feeding than 13-lipoxygenases, suggesting an as yet unknown function in maize defense against herbivory. Together, these results provide a comprehensive view of the dynamic transcriptomic and metabolomic responses of maize leaves to caterpillar feeding.
Collapse
Affiliation(s)
- Vered Tzin
- Boyce Thompson Institute for Plant Research, Tower Rd, Ithaca, NY, USA
- Correspondence:
| | - Yuko Hojo
- Okayama University, Institute of Plant Science and Resources, Kurashiki, Okayama, Japan
| | - Susan R Strickler
- Boyce Thompson Institute for Plant Research, Tower Rd, Ithaca, NY, USA
| | - Lee J Bartsch
- Boyce Thompson Institute for Plant Research, Tower Rd, Ithaca, NY, USA
| | - Cairo M Archer
- Boyce Thompson Institute for Plant Research, Tower Rd, Ithaca, NY, USA
| | - Kevin R Ahern
- Boyce Thompson Institute for Plant Research, Tower Rd, Ithaca, NY, USA
| | - Shaoqun Zhou
- Boyce Thompson Institute for Plant Research, Tower Rd, Ithaca, NY, USA
| | - Shawn A Christensen
- USDA-ARS Chemistry Unit, Center for Medical, Agricultural, and Veterinary Entomology, Gainesville, FL, USA
| | - Ivan Galis
- Okayama University, Institute of Plant Science and Resources, Kurashiki, Okayama, Japan
| | - Lukas A Mueller
- Boyce Thompson Institute for Plant Research, Tower Rd, Ithaca, NY, USA
| | - Georg Jander
- Boyce Thompson Institute for Plant Research, Tower Rd, Ithaca, NY, USA
| |
Collapse
|
44
|
Strable J, Wallace JG, Unger-Wallace E, Briggs S, Bradbury PJ, Buckler ES, Vollbrecht E. Maize YABBY Genes drooping leaf1 and drooping leaf2 Regulate Plant Architecture. THE PLANT CELL 2017; 29:1622-1641. [PMID: 28698237 PMCID: PMC5559738 DOI: 10.1105/tpc.16.00477] [Citation(s) in RCA: 90] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Revised: 06/12/2017] [Accepted: 07/07/2017] [Indexed: 05/19/2023]
Abstract
Leaf architecture directly influences canopy structure, consequentially affecting yield. We discovered a maize (Zea mays) mutant with aberrant leaf architecture, which we named drooping leaf1 (drl1). Pleiotropic mutations in drl1 affect leaf length and width, leaf angle, and internode length and diameter. These phenotypes are enhanced by natural variation at the drl2 enhancer locus, including reduced expression of the drl2-Mo17 allele in the Mo17 inbred. A second drl2 allele, produced by transposon mutagenesis, interacted synergistically with drl1 mutants and reduced drl2 transcript levels. The drl genes are required for proper leaf patterning, development and cell proliferation of leaf support tissues, and for restricting auricle expansion at the midrib. The paralogous loci encode maize CRABS CLAW co-orthologs in the YABBY family of transcriptional regulators. The drl genes are coexpressed in incipient and emergent leaf primordia at the shoot apex, but not in the vegetative meristem or stem. Genome-wide association studies using maize NAM-RIL (nested association mapping-recombinant inbred line) populations indicated that the drl loci reside within quantitative trait locus regions for leaf angle, leaf width, and internode length and identified rare single nucleotide polymorphisms with large phenotypic effects for the latter two traits. This study demonstrates that drl genes control the development of key agronomic traits in maize.
Collapse
Affiliation(s)
- Josh Strable
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, Iowa 50011
- Interdepartmental Plant Biology, Iowa State University, Ames, Iowa 50011
| | - Jason G Wallace
- Department of Crop and Soil Sciences, The University of Georgia, Athens, Georgia 30602
| | - Erica Unger-Wallace
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, Iowa 50011
| | - Sarah Briggs
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, Iowa 50011
| | - Peter J Bradbury
- U.S. Department of Agriculture-Agriculture Research Service, Ithaca, New York 14853
| | - Edward S Buckler
- U.S. Department of Agriculture-Agriculture Research Service, Ithaca, New York 14853
- Department of Plant Breeding and Genetics, Cornell University, Ithaca, New York 14853
| | - Erik Vollbrecht
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, Iowa 50011
- Interdepartmental Plant Biology, Iowa State University, Ames, Iowa 50011
| |
Collapse
|
45
|
Nadal M, Sawers R, Naseem S, Bassin B, Kulicke C, Sharman A, An G, An K, Ahern KR, Romag A, Brutnell TP, Gutjahr C, Geldner N, Roux C, Martinoia E, Konopka JB, Paszkowski U. An N-acetylglucosamine transporter required for arbuscular mycorrhizal symbioses in rice and maize. NATURE PLANTS 2017; 3:17073. [PMID: 28548655 PMCID: PMC5685555 DOI: 10.1038/nplants.2017.73] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2016] [Accepted: 04/25/2017] [Indexed: 05/20/2023]
Abstract
Most terrestrial plants, including crops, engage in beneficial interactions with arbuscular mycorrhizal fungi. Vital to the association is mutual recognition involving the release of diffusible signals into the rhizosphere. Previously, we identified the maize no perception 1 (nope1) mutant to be defective in early signalling. Here, we report cloning of ZmNope1 on the basis of synteny with rice. NOPE1 encodes a functional homologue of the Candida albicans N-acetylglucosamine (GlcNAc) transporter NGT1, and represents the first plasma membrane GlcNAc transporter identified from plants. In C. albicans, exposure to GlcNAc activates cell signalling and virulence. Similarly, in Rhizophagus irregularis treatment with rice wild-type but not nope1 root exudates induced transcriptome changes associated with signalling function, suggesting a requirement of NOPE1 function for presymbiotic fungal reprogramming.
Collapse
Affiliation(s)
- Marina Nadal
- Department of Plant Sciences, University of Cambridge, Cambridge, CB2 3EA, UK
- Department of Plant Molecular Biology, University of Lausanne, 1015 Lausanne, Switzerland
| | - Ruairidh Sawers
- Department of Plant Molecular Biology, University of Lausanne, 1015 Lausanne, Switzerland
| | - Shamoon Naseem
- Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, NY 11794-5222, USA
| | - Barbara Bassin
- Institute of Plant Biology, University of Zurich, 8008 Zurich, Switzerland
| | - Corinna Kulicke
- Department of Plant Sciences, University of Cambridge, Cambridge, CB2 3EA, UK
| | - Abigail Sharman
- Department of Plant Sciences, University of Cambridge, Cambridge, CB2 3EA, UK
| | - Gynheung An
- Crop Biotech Institute and Graduate School of Biotechnology, Kyung Hee University, Yongin 17104, Korea
| | - Kyungsook An
- Crop Biotech Institute and Graduate School of Biotechnology, Kyung Hee University, Yongin 17104, Korea
| | - Kevin R. Ahern
- Boyce Thompson Institute for Plant Research, Ithaca, New York 14853, USA
| | - Amanda Romag
- Boyce Thompson Institute for Plant Research, Ithaca, New York 14853, USA
| | - Thomas P. Brutnell
- Boyce Thompson Institute for Plant Research, Ithaca, New York 14853, USA
| | - Caroline Gutjahr
- Department of Plant Molecular Biology, University of Lausanne, 1015 Lausanne, Switzerland
| | - Niko Geldner
- Department of Plant Molecular Biology, University of Lausanne, 1015 Lausanne, Switzerland
| | - Christophe Roux
- Université de Toulouse, UPS, UMR5546, Laboratoire de recherche en Sciences Végétales, BP 42617, F-31326 Castanet-Tolosan CEDEX, France
| | - Enrico Martinoia
- Institute of Plant Biology, University of Zurich, 8008 Zurich, Switzerland
| | - James B. Konopka
- Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, NY 11794-5222, USA
| | - Uta Paszkowski
- Department of Plant Sciences, University of Cambridge, Cambridge, CB2 3EA, UK
- Department of Plant Molecular Biology, University of Lausanne, 1015 Lausanne, Switzerland
- to whom correspondence should be addressed: Uta Paszkowski,
| |
Collapse
|
46
|
Michel AH, Hatakeyama R, Kimmig P, Arter M, Peter M, Matos J, De Virgilio C, Kornmann B. Functional mapping of yeast genomes by saturated transposition. eLife 2017; 6. [PMID: 28481201 PMCID: PMC5466422 DOI: 10.7554/elife.23570] [Citation(s) in RCA: 89] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Accepted: 05/06/2017] [Indexed: 12/17/2022] Open
Abstract
Yeast is a powerful model for systems genetics. We present a versatile, time- and labor-efficient method to functionally explore the Saccharomyces cerevisiae genome using saturated transposon mutagenesis coupled to high-throughput sequencing. SAturated Transposon Analysis in Yeast (SATAY) allows one-step mapping of all genetic loci in which transposons can insert without disrupting essential functions. SATAY is particularly suited to discover loci important for growth under various conditions. SATAY (1) reveals positive and negative genetic interactions in single and multiple mutant strains, (2) can identify drug targets, (3) detects not only essential genes, but also essential protein domains, (4) generates both null and other informative alleles. In a SATAY screen for rapamycin-resistant mutants, we identify Pib2 (PhosphoInositide-Binding 2) as a master regulator of TORC1. We describe two antagonistic TORC1-activating and -inhibiting activities located on opposite ends of Pib2. Thus, SATAY allows to easily explore the yeast genome at unprecedented resolution and throughput. DOI:http://dx.doi.org/10.7554/eLife.23570.001 Genes are stretches of DNA that carry the instructions to build and maintain cells. Many studies in genetics involve inactivating one or more genes and observing the consequences. If the loss of a gene kills the cell, that gene is likely to be vital for life. If it does not, the gene may not be essential, or a similar gene may be able to take over its role. Baker’s yeast is a simple organism that shares many characteristics with human cells. Many yeast genes have a counterpart among human genes, and so studying baker’s yeast can reveal clues about our own genetics. Michel et al. report an adaptation for baker’s yeast of a technique called “Transposon sequencing”, which had been used in other single-celled organisms to study the effects of interrupting genes. Briefly, a virus-like piece of DNA, called a transposon, inserts randomly into the genetic material and switches off individual genes. The DNA is then sequenced to reveal every gene that can be disrupted without killing the cell, and remaining genes are inferred to be essential for life. The approach, named SATAY (which is short for “saturated transposon analysis in yeast”), uses this strategy to create millions of baker’s yeast cells, each with a different gene switched off. Because the number of cells generated this way vastly exceeds the number of genes, every gene will be switched off by several independent transposons. Therefore the technique allows all yeast genes to be inactivated several times in one single experiment. The cells can be grown in varying conditions during the experiment, revealing the genes needed for survival in different situations. Non-essential genes can also be inactivated beforehand to uncover if any genes might be compensating for their absence. In the future, this technique may be used to better understand human diseases, such as cancer, since many disease-causing genes in humans have counterparts in yeast. DOI:http://dx.doi.org/10.7554/eLife.23570.002
Collapse
Affiliation(s)
- Agnès H Michel
- Institute of Biochemistry, ETH Zurich, Zurich, Switzerland
| | - Riko Hatakeyama
- Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Philipp Kimmig
- Institute of Biochemistry, ETH Zurich, Zurich, Switzerland
| | - Meret Arter
- Institute of Biochemistry, ETH Zurich, Zurich, Switzerland
| | - Matthias Peter
- Institute of Biochemistry, ETH Zurich, Zurich, Switzerland
| | - Joao Matos
- Institute of Biochemistry, ETH Zurich, Zurich, Switzerland
| | | | | |
Collapse
|
47
|
Negi P, Rai AN, Suprasanna P. Moving through the Stressed Genome: Emerging Regulatory Roles for Transposons in Plant Stress Response. FRONTIERS IN PLANT SCIENCE 2016; 7:1448. [PMID: 27777577 PMCID: PMC5056178 DOI: 10.3389/fpls.2016.01448] [Citation(s) in RCA: 81] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2016] [Accepted: 09/12/2016] [Indexed: 05/02/2023]
Abstract
The recognition of a positive correlation between organism genome size with its transposable element (TE) content, represents a key discovery of the field of genome biology. Considerable evidence accumulated since then suggests the involvement of TEs in genome structure, evolution and function. The global genome reorganization brought about by transposon activity might play an adaptive/regulatory role in the host response to environmental challenges, reminiscent of McClintock's original 'Controlling Element' hypothesis. This regulatory aspect of TEs is also garnering support in light of the recent evidences, which project TEs as "distributed genomic control modules." According to this view, TEs are capable of actively reprogramming host genes circuits and ultimately fine-tuning the host response to specific environmental stimuli. Moreover, the stress-induced changes in epigenetic status of TE activity may allow TEs to propagate their stress responsive elements to host genes; the resulting genome fluidity can permit phenotypic plasticity and adaptation to stress. Given their predominating presence in the plant genomes, nested organization in the genic regions and potential regulatory role in stress response, TEs hold unexplored potential for crop improvement programs. This review intends to present the current information about the roles played by TEs in plant genome organization, evolution, and function and highlight the regulatory mechanisms in plant stress responses. We will also briefly discuss the connection between TE activity, host epigenetic response and phenotypic plasticity as a critical link for traversing the translational bridge from a purely basic study of TEs, to the applied field of stress adaptation and crop improvement.
Collapse
Affiliation(s)
| | | | - Penna Suprasanna
- Plant Stress Physiology and Biotechnology Section, Nuclear Agriculture and Biotechnology Division, Bhabha Atomic Research CentreTrombay, India
| |
Collapse
|
48
|
Salazar-Vidal MN, Acosta-Segovia E, Sánchez-León N, Ahern KR, Brutnell TP, Sawers RJH. Characterization and Transposon Mutagenesis of the Maize (Zea mays) Pho1 Gene Family. PLoS One 2016; 11:e0161882. [PMID: 27648940 PMCID: PMC5029887 DOI: 10.1371/journal.pone.0161882] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Accepted: 08/12/2016] [Indexed: 12/25/2022] Open
Abstract
Phosphorus is an essential nutrient for all plants, but also one of the least mobile, and consequently least available, in the soil. Plants have evolved a series of molecular, metabolic and developmental adaptations to increase the acquisition of phosphorus and to maximize the efficiency of use within the plant. In Arabidopsis (Arabidopsis thaliana), the AtPHO1 protein regulates and facilitates the distribution of phosphorus. To investigate the role of PHO1 proteins in maize (Zea mays), the B73 reference genome was searched for homologous sequences, and four genes identified that were designated ZmPho1;1, ZmPho1;2a, ZmPho1;2b and ZmPho1;3. ZmPho1;2a and ZmPho1;2b are the most similar to AtPHO1, and represent candidate co-orthologs that we hypothesize to have been retained following whole genome duplication. Evidence was obtained for the production of natural anti-sense transcripts associated with both ZmPho1;2a and ZmPho1;2b, suggesting the possibility of regulatory crosstalk between paralogs. To characterize functional divergence between ZmPho1;2a and ZmPho1;2b, a program of transposon mutagenesis was initiated using the Ac/Ds system, and, here, we report the generation of novel alleles of ZmPho1;2a and ZmPho1;2b.
Collapse
Affiliation(s)
- M. Nancy Salazar-Vidal
- Laboratorio Nacional de Genómica para la Biodiversidad (LANGEBIO), Unidad de Genómica Avanzada, Centro de Investigaciones y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), Irapuato C.P. 36821, Guanajuato, México
| | - Edith Acosta-Segovia
- Laboratorio Nacional de Genómica para la Biodiversidad (LANGEBIO), Unidad de Genómica Avanzada, Centro de Investigaciones y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), Irapuato C.P. 36821, Guanajuato, México
| | - Nidia Sánchez-León
- Laboratorio Nacional de Genómica para la Biodiversidad (LANGEBIO), Unidad de Genómica Avanzada, Centro de Investigaciones y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), Irapuato C.P. 36821, Guanajuato, México
| | - Kevin R. Ahern
- Boyce Thompson Institute for Plant Research, Ithaca, New York 14853-1801, United States of America
| | - Thomas P. Brutnell
- Donald Danforth Plant Science Center, St. Louis, Missouri 63132, United States of America
| | - Ruairidh J. H. Sawers
- Laboratorio Nacional de Genómica para la Biodiversidad (LANGEBIO), Unidad de Genómica Avanzada, Centro de Investigaciones y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), Irapuato C.P. 36821, Guanajuato, México
- * E-mail:
| |
Collapse
|
49
|
Liu P, McCarty DR, Koch KE. Transposon Mutagenesis and Analysis of Mutants in UniformMu Maize (
Zea mays
). ACTA ACUST UNITED AC 2016; 1:451-465. [DOI: 10.1002/cppb.20029] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Peng Liu
- Horticultural Sciences Department and Plant Molecular and Cellular Biology Program, University of Florida Gainesville Florida
| | - Donald R. McCarty
- Horticultural Sciences Department and Plant Molecular and Cellular Biology Program, University of Florida Gainesville Florida
| | - Karen E. Koch
- Horticultural Sciences Department and Plant Molecular and Cellular Biology Program, University of Florida Gainesville Florida
| |
Collapse
|
50
|
A Population of Deletion Mutants and an Integrated Mapping and Exome-seq Pipeline for Gene Discovery in Maize. G3-GENES GENOMES GENETICS 2016; 6:2385-95. [PMID: 27261000 PMCID: PMC4978893 DOI: 10.1534/g3.116.030528] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
To better understand maize endosperm filling and maturation, we used γ-irradiation of the B73 maize reference line to generate mutants with opaque endosperm and reduced kernel fill phenotypes, and created a population of 1788 lines including 39 Mo17 × F2s showing stable, segregating, and viable kernel phenotypes. For molecular characterization of the mutants, we developed a novel functional genomics platform that combined bulked segregant RNA and exome sequencing (BSREx-seq) to map causative mutations and identify candidate genes within mapping intervals. To exemplify the utility of the mutants and provide proof-of-concept for the bioinformatics platform, we present detailed characterization of line 937, an opaque mutant harboring a 6203 bp in-frame deletion covering six exons within the Opaque-1 gene. In addition, we describe mutant line 146 which contains a 4.8 kb intragene deletion within the Sugary-1 gene and line 916 in which an 8.6 kb deletion knocks out a Cyclin A2 gene. The publically available algorithm developed in this work improves the identification of causative deletions and its corresponding gaps within mapping peaks. This study demonstrates the utility of γ-irradiation for forward genetics in large nondense genomes such as maize since deletions often affect single genes. Furthermore, we show how this classical mutagenesis method becomes applicable for functional genomics when combined with state-of-the-art genomics tools.
Collapse
|