1
|
Buss W, Ford BA, Foo E, Schnippenkoetter W, Borrill P, Brooks B, Ashton AR, Chandler PM, Spielmeyer W. Overgrowth mutants determine the causal role of gibberellin GA2oxidaseA13 in Rht12 dwarfism of wheat. J Exp Bot 2020; 71:7171-7178. [PMID: 32949136 DOI: 10.1093/jxb/eraa443] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2020] [Accepted: 09/16/2020] [Indexed: 06/11/2023]
Abstract
The induced dwarf mutant Rht12 was previously shown to have agronomic potential to replace the conventional DELLA mutants Rht-B1b/Rht-D1b in wheat. The Rht12 dwarfing gene is not associated with reduced coleoptile length (unlike the DELLA mutants) and it is dominant, characteristics which are shared with the previously characterized dwarfing genes Rht18 and Rht14. Using the Rht18/Rht14 model, a gibberellin (GA) 2-oxidase gene was identified in the Rht12 region on chromosome 5A. A screen for suppressor mutants in the Rht12 background identified tall overgrowth individuals that were shown to contain loss-of-function mutations in GA2oxidaseA13, demonstrating the role of this gene in the Rht12 dwarf phenotype. It was concluded that Rht12, Rht18, and Rht14 share the same height-reducing mechanism through the increased expression of GA 2-oxidase genes. Some of the overgrowth mutants generated in this study were semi-dwarf and taller than the original Rht12 dwarf, providing breeders with new sources of agronomically useful dwarfism.
Collapse
Affiliation(s)
- Wolfram Buss
- CSIRO Agriculture and Food, Canberra, ACT, Australia
| | - Brett A Ford
- CSIRO Agriculture and Food, Canberra, ACT, Australia
| | - Eloise Foo
- The School of Natural Sciences, University of Tasmania, Hobart, Tasmania, Australia
| | | | - Philippa Borrill
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham, UK
| | | | | | | | | |
Collapse
|
2
|
Grantham MA, Ford BA, Worley AC. Pollination and fruit set in two rewardless slipper orchids and their hybrids (Cypripedium, Orchidaceae): large yellow flowers outperform small white flowers in the northern tall grass prairie. Plant Biol (Stuttg) 2019; 21:997-1007. [PMID: 31276285 DOI: 10.1111/plb.13026] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Accepted: 07/01/2019] [Indexed: 06/09/2023]
Abstract
Species with rewardless flowers often have low fruit to flower ratios, although wide temporal and spatial variation in fruiting success can occur. We compared floral phenotypes, insect visitors and fruiting success in four populations of the small white (Cypripedium candidum) and yellow (C. parviflorum) lady's slipper orchids and their hybrids near the northern extent of North America's tall grass prairie. Flower and fruit numbers were observed for two seasons on marked individuals (n = 1811). Floral traits were measured on 82-140 individuals per taxon and analysed in relation to fruiting success. All insects found inside flowers were collected, inspected for pollen smears and measured for comparison to floral features. Among orchid taxa, C. candidum had the smallest flowers, lowest number and variety of insect visitors, and lowest fruit to flower ratios. These measures were intermediate in hybrids and highest in C. parviflorum, despite low flower numbers in the latter. Within orchid taxa, fruit number was positively related to flower number, but fruit to flower ratios decreased slightly, as would be expected if pollinators left unrewarding patches. Potential pollinators included the dipteran Odontomyia pubescens and hymenopterans Andrena spp., Apis mellifera and Lasioglossum zonulum. Cypripedium parviflorum had a reproductive advantage over C. candidum across multiple populations and years. Hybrids showed segregation for floral traits, and hybrid fruiting success increased with a deeper intensity of yellow pigment and larger escape routes for floral visitors. These same attributes likely contributed to the relatively high fruit set in C. parviflorum in the study region.
Collapse
Affiliation(s)
- M A Grantham
- Department of Biological Sciences, University of Manitoba, Winnipeg, MB, R3T 2N2, Canada
| | - B A Ford
- Department of Biological Sciences, University of Manitoba, Winnipeg, MB, R3T 2N2, Canada
| | - A C Worley
- Department of Biological Sciences, University of Manitoba, Winnipeg, MB, R3T 2N2, Canada
| |
Collapse
|
3
|
Bovill WD, Hyles J, Zwart AB, Ford BA, Perera G, Phongkham T, Brooks BJ, Rebetzke GJ, Hayden MJ, Hunt JR, Spielmeyer W. Increase in coleoptile length and establishment by Lcol-A1, a genetic locus with major effect in wheat. BMC Plant Biol 2019; 19:332. [PMID: 31357930 PMCID: PMC6664495 DOI: 10.1186/s12870-019-1919-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Accepted: 07/02/2019] [Indexed: 05/23/2023]
Abstract
BACKGROUND Good establishment is important for rapid leaf area development in wheat crops. Poor establishment results in fewer, later-emerging plants, reduced leaf area and tiller number. In addition, poorly established crops suffer from increased soil moisture loss through evaporation and greater competition from weeds while fewer spikes are produced which can reduce grain yield. By protecting the emerging first leaf, the coleoptile is critical for achieving good establishment, and its length and interaction with soil physical properties determine the ability of a cultivar to emerge from depth. RESULTS Here we characterise a locus on chromosome 1AS, that increases coleoptile length in wheat, which we designate as Lcol-A1. We identified Lcol-A1 by bulked-segregant analysis and used a Halberd-derived population to fine map the gene to a 2 cM region, equivalent to 7 Mb on the IWGSC genome reference sequence of Chinese Spring (RefSeqv1.0). By sowing recently released cultivars and near-isogenic lines in the field at both conventional and deep sowing depths, we confirmed that Locl-A1 was associated with increased emergence from depth in the presence and absence of conventional dwarfing genes. Flanking markers IWB58229 and IWA710 were developed to assist breeders to select for long coleoptile wheats. CONCLUSIONS Increased coleoptile length is sought in many global wheat production areas to improve crop emergence. The identification of the gene Lcol-A1, together with tools to allow wheat breeders to track the gene, will enable improvements to be made for this important trait.
Collapse
Affiliation(s)
- William D. Bovill
- CSIRO Agriculture and Food, P.O. Box 1700, Canberra, ACT 2601 Australia
| | - Jessica Hyles
- CSIRO Agriculture and Food, P.O. Box 1700, Canberra, ACT 2601 Australia
| | | | - Brett A. Ford
- CSIRO Agriculture and Food, P.O. Box 1700, Canberra, ACT 2601 Australia
| | - Geetha Perera
- CSIRO Agriculture and Food, P.O. Box 1700, Canberra, ACT 2601 Australia
| | - Tanya Phongkham
- CSIRO Agriculture and Food, P.O. Box 1700, Canberra, ACT 2601 Australia
| | - Brenton J. Brooks
- CSIRO Agriculture and Food, P.O. Box 1700, Canberra, ACT 2601 Australia
| | | | - Matthew J. Hayden
- Agriculture Victoria Research, AgriBio Centre for AgriBiosciences, Bundoora, VIC 3086 Australia
| | - James R. Hunt
- Department of Animal, Plant and Soil Sciences, AgriBio Centre for AgriBiosciences, La Trobe University, Bundoora, VIC 3086 Australia
| | | |
Collapse
|
4
|
Ford BA, Foo E, Sharwood R, Karafiatova M, Vrána J, MacMillan C, Nichols DS, Steuernagel B, Uauy C, Doležel J, Chandler PM, Spielmeyer W. Rht18 Semidwarfism in Wheat Is Due to Increased GA 2-oxidaseA9 Expression and Reduced GA Content. Plant Physiol 2018; 177:168-180. [PMID: 29545269 PMCID: PMC5933146 DOI: 10.1104/pp.18.00023] [Citation(s) in RCA: 73] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Accepted: 03/04/2018] [Indexed: 05/04/2023]
Abstract
Semidwarfing genes have improved crop yield by reducing height, improving lodging resistance, and allowing plants to allocate more assimilates to grain growth. In wheat (Triticum aestivum), the Rht18 semidwarfing gene was identified and deployed in durum wheat before it was transferred into bread wheat, where it was shown to have agronomic potential. Rht18, a dominant and gibberellin (GA) responsive mutant, is genetically and functionally distinct from the widely used GA-insensitive semidwarfing genes Rht-B1b and Rht-D1b In this study, the Rht18 gene was identified by mutagenizing the semidwarf durum cultivar Icaro (Rht18) and generating mutants with a range of tall phenotypes. Isolating and sequencing chromosome 6A of these "overgrowth" mutants showed that they contained independent mutations in the coding region of GA2oxA9GA2oxA9 is predicted to encode a GA 2-oxidase that metabolizes GA biosynthetic intermediates into inactive products, effectively reducing the amount of bioactive GA (GA1). Functional analysis of the GA2oxA9 protein demonstrated that GA2oxA9 converts the intermediate GA12 to the inactive metabolite GA110 Furthermore, Rht18 showed higher expression of GA2oxA9 and lower GA content compared with its tall parent. These data indicate that the increased expression of GA2oxA9 in Rht18 results in a reduction of both bioactive GA content and plant height. This study describes a height-reducing mechanism that can generate new genetic diversity for semidwarfism in wheat by combining increased expression with mutations of specific amino acid residues in GA2oxA9.
Collapse
Affiliation(s)
- Brett A Ford
- CSIRO Agriculture and Food, Canberra, ACT 2601, Australia
| | - Eloise Foo
- The School of Natural Sciences, University of Tasmania, Hobart, Tasmania 7001, Australia
| | - Robert Sharwood
- Research School of Biology, The Australian National University, Canberra, ACT 0200, Australia
| | - Miroslava Karafiatova
- Institute of Experimental Botany, Centre of the Region Haná for Biotechnological and Agricultural Research, CZ-78371 Olomouc, Czech Republic
| | - Jan Vrána
- Institute of Experimental Botany, Centre of the Region Haná for Biotechnological and Agricultural Research, CZ-78371 Olomouc, Czech Republic
| | | | - David S Nichols
- Central Science Laboratories, University of Tasmania, Hobart, Tasmania 7001, Australia
| | | | | | - Jaroslav Doležel
- Institute of Experimental Botany, Centre of the Region Haná for Biotechnological and Agricultural Research, CZ-78371 Olomouc, Czech Republic
| | | | | |
Collapse
|
5
|
Ashnest JR, Huynh DL, Dragwidge JM, Ford BA, Gendall AR. Arabidopsis Intracellular NHX-Type Sodium-Proton Antiporters are Required for Seed Storage Protein Processing. Plant Cell Physiol 2015; 56:2220-33. [PMID: 26416852 DOI: 10.1093/pcp/pcv138] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Accepted: 09/18/2015] [Indexed: 05/26/2023]
Abstract
The Arabidopsis intracellular sodium-proton exchanger (NHX) proteins AtNHX5 and AtNHX6 have a well-documented role in plant development, and have been used to improve salt tolerance in a variety of species. Despite evidence that intracellular NHX proteins are important in vacuolar trafficking, the mechanism of this role is poorly understood. Here we show that NHX5 and NHX6 are necessary for processing of the predominant seed storage proteins, and also influence the processing and activity of a vacuolar processing enzyme. Furthermore, we show by yeast two-hybrid and bimolecular fluorescence complementation (BiFC) technology that the C-terminal tail of NHX6 interacts with a component of Retromer, another component of the cell sorting machinery, and that this tail is critical for NHX6 activity. These findings demonstrate that NHX5 and NHX6 are important in processing and activity of vacuolar cargo, and suggest a mechanism by which NHX intracellular (IC)-II antiporters may be involved in subcellular trafficking.
Collapse
Affiliation(s)
- Joanne R Ashnest
- Department of Animal, Plant and Soil Sciences, AgriBio, Centre for AgriBiosciences, 5 Ring Road, La Trobe University, Bundoora, VIC 3086, Australia
| | - Dung L Huynh
- Department of Animal, Plant and Soil Sciences, AgriBio, Centre for AgriBiosciences, 5 Ring Road, La Trobe University, Bundoora, VIC 3086, Australia
| | - Jonathan M Dragwidge
- Department of Animal, Plant and Soil Sciences, AgriBio, Centre for AgriBiosciences, 5 Ring Road, La Trobe University, Bundoora, VIC 3086, Australia
| | - Brett A Ford
- Department of Animal, Plant and Soil Sciences, AgriBio, Centre for AgriBiosciences, 5 Ring Road, La Trobe University, Bundoora, VIC 3086, Australia Present address: Commonwealth Scientific and Industrial Research Organization Agriculture Flagship, Clunies Ross Street, Acton, ACT 2601, Australia
| | - Anthony R Gendall
- Department of Animal, Plant and Soil Sciences, AgriBio, Centre for AgriBiosciences, 5 Ring Road, La Trobe University, Bundoora, VIC 3086, Australia
| |
Collapse
|
6
|
Ford BA, Ernest JR, Gendall AR. Identification and characterization of orthologs of AtNHX5 and AtNHX6 in Brassica napus. Front Plant Sci 2012; 3:208. [PMID: 22973287 PMCID: PMC3438465 DOI: 10.3389/fpls.2012.00208] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2012] [Accepted: 08/16/2012] [Indexed: 05/06/2023]
Abstract
Improving crop species by breeding for salt tolerance or introducing salt tolerant traits is one method of increasing crop yields in saline affected areas. Extensive studies of the model plant species Arabidopsis thaliana has led to the availability of substantial information regarding the function and importance of many genes involved in salt tolerance. However, the identification and characterization of A. thaliana orthologs in species such as Brassica napus (oilseed rape) can prove difficult due to the significant genomic changes that have occurred since their divergence approximately 20 million years ago (MYA). The recently released Brassica rapa genome provides an excellent resource for comparative studies of A. thaliana and the cultivated Brassica species, and facilitates the identification of Brassica species orthologs which may be of agronomic importance. Sodium hydrogen antiporter (NHX) proteins transport a sodium or potassium ion in exchange for a hydrogen ion in the other direction across a membrane. In A. thaliana there are eight members of the NHX family, designated AtNHX1-8, that can be sub-divided into three clades, based on their subcellular localization: plasma membrane (PM), intracellular class I (IC-I) and intracellular class II (IC-II). In plants, many NHX proteins are primary determinants of salt tolerance and act by transporting Na(+) out of the cytosol where it would otherwise accumulate to toxic levels. Significant work has been done to determine the role of both PM and IC-I clade members in salt tolerance in a variety of plant species, but relatively little analysis has been described for the IC-II clade. Here we describe the identification of B. napus orthologs of AtNHX5 and AtNHX6, using the B. rapa genome sequence, macro- and micro-synteny analysis, comparative expression and promoter motif analysis, and highlight the value of these multiple approaches for identifying true orthologs in closely related species with multiple paralogs.
Collapse
Affiliation(s)
| | | | - Anthony R. Gendall
- *Correspondence: Anthony R. Gendall, Department of Botany, La Trobe University, Bundoora, Melbourne, VIC, Australia. e-mail:
| |
Collapse
|
7
|
Starr JR, Bayer RJ, Ford BA. The phylogenetic position of Carex section Phyllostachys and its implications for phylogeny and subgeneric circumscription in Carex (Cyperaceae). Am J Bot 1999; 86:563-577. [PMID: 10205077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Wide speculation surrounds the origin and phylogenetic relationships of the most highly reduced sections in the genus Carex. In order to gain a better understanding of phylogeny in Carex, the relationship of the reduced sect. Phyllostachys to 12 putatively related sections, representing all four subgenera (Primocarex, Indocarex, Carex, Vignea), was inferred from sequences of the ITS (internal transcribed spacer) region of nrDNA. Phylogenetic reconstructions identified two main clades: (1) a "compound" clade composed of sections from subg. Indocarex, Primocarex, and a portion of subg. Carex, and (2) a "reduced" clade consisting of sections from subg. Carex (Phyllostachys) and Primocarex (Filifoliae and Firmiculmes). Subgenus Indocarex was paraphyletic within the "compound" clade supporting classifications that have merged it within a wider subg. Indocarex/Carex/Primocarex line. Subgenus Primocarex was polyphyletic. This result was consistent with theories that extreme reduction has occurred along several different evolutionary lines in Carex. Phylogenetic theories inferred from the presence or abnormal growth of the rachilla were not supported by tree topologies. Difficult sectional circumscriptions, such as the separation of sections Laxiflorae and Careyanae, were strongly upheld by sequence data. The ITS region is an effective tool for defining sectional limits and for estimating relationships among sections in Carex, but does not provide enough phylogenetic information to fully resolve relationships below the sectional level.
Collapse
Affiliation(s)
- J R Starr
- Department of Botany, University of Manitoba, Winnipeg, Manitoba, R3T 2N2 Canada; and
| | | | | |
Collapse
|