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Zhang J, Sun L, Wang Y, Li B, Li X, Ye Z, Zhang J. A Calcium-Dependent Protein Kinase Regulates the Defense Response in Citrus sinensis. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2024; 37:459-466. [PMID: 38597923 DOI: 10.1094/mpmi-12-23-0208-r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/11/2024]
Abstract
Citrus Huanglongbing (HLB), which is caused by 'Candidatus Liberibacter asiaticus' (CLas), is one of the most destructive citrus diseases worldwide, and defense-related Citrus sinensis gene resources remain largely unexplored. Calcium signaling plays an important role in diverse biological processes. In plants, a few calcium-dependent protein kinases (CDPKs/CPKs) have been shown to contribute to defense against pathogenic microbes. The genome of C. sinensis encodes dozens of CPKs. In this study, the role of C. sinensis calcium-dependent protein kinases (CsCPKs) in C. sinensis defense was investigated. Silencing of CsCPK6 compromised the induction of defense-related genes in C. sinensis. Expression of a constitutively active form of CsCPK6 (CsCPK6CA) triggered the activation of defense-related genes in C. sinensis. Complementation of CsCPK6 rescued the defense-related gene induction in an Arabidopsis thaliana cpk4/11 mutant, indicating that CsCPK6 carries CPK activity and is capable of functioning as a CPK in Arabidopsis. Moreover, an effector derived from CLas inhibits defense induced by the expression of CsCPK6CA and autophosphorylation of CsCPK6, which suggests the involvement of CsCPK6 and calcium signaling in defense. These results support a positive role for CsCPK6 in C. sinensis defense against CLas, and the autoinhibitory regulation of CsCPK6 provides a potential genome-editing target for improving C. sinensis defense. [Formula: see text] Copyright © 2024 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.
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Affiliation(s)
- Jinghan Zhang
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
- School of Life Sciences, Hebei University, Baoding, Hebei 071002, China
| | - Lifan Sun
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Yu Wang
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Baiyang Li
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Xiangguo Li
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
- College of Agronomy, Shanxi Agricultural University, Taigu 030801, China
| | - Ziqin Ye
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Jie Zhang
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
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Godwin J, Govindasamy M, Nedounsejian K, March E, Halton R, Bourbousse C, Wolff L, Fort A, Krzyszton M, López Corrales J, Swiezewski S, Barneche F, Schubert D, Farrona S. The UBP5 histone H2A deubiquitinase counteracts PRCs-mediated repression to regulate Arabidopsis development. Nat Commun 2024; 15:667. [PMID: 38253560 PMCID: PMC10803359 DOI: 10.1038/s41467-023-44546-8] [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: 11/15/2022] [Accepted: 12/15/2023] [Indexed: 01/24/2024] Open
Abstract
Polycomb Repressive Complexes (PRCs) control gene expression through the incorporation of H2Aub and H3K27me3. In recent years, there is increasing evidence of the complexity of PRCs' interaction networks and the interplay of these interactors with PRCs in epigenome reshaping, which is fundamental to understand gene regulatory mechanisms. Here, we identified UBIQUITIN SPECIFIC PROTEASE 5 (UBP5) as a chromatin player able to counteract the deposition of the two PRCs' epigenetic hallmarks in Arabidopsis thaliana. We demonstrated that UBP5 is a plant developmental regulator based on functional analyses of ubp5-CRISPR Cas9 mutant plants. UBP5 promotes H2A monoubiquitination erasure, leading to transcriptional de-repression. Furthermore, preferential association of UBP5 at PRC2 recruiting motifs and local H3K27me3 gaining in ubp5 mutant plants suggest the existence of functional interplays between UBP5 and PRC2 in regulating epigenome dynamics. In summary, acting as an antagonist of the pivotal epigenetic repressive marks H2Aub and H3K27me3, UBP5 provides novel insights to disentangle the complex regulation of PRCs' activities.
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Affiliation(s)
- James Godwin
- School of Biological and Chemical Sciences, College of Science and Engineering, University of Galway, H91 TK33, Galway, Ireland
- Donald Danforth Plant Science Center, St. Louis, MO, 63132, USA
| | - Mohan Govindasamy
- School of Biological and Chemical Sciences, College of Science and Engineering, University of Galway, H91 TK33, Galway, Ireland
| | - Kiruba Nedounsejian
- School of Biological and Chemical Sciences, College of Science and Engineering, University of Galway, H91 TK33, Galway, Ireland
| | - Eduardo March
- School of Biological and Chemical Sciences, College of Science and Engineering, University of Galway, H91 TK33, Galway, Ireland
| | - Ronan Halton
- School of Biological and Chemical Sciences, College of Science and Engineering, University of Galway, H91 TK33, Galway, Ireland
| | - Clara Bourbousse
- Institut de Biologie de l'École Normale Supérieure (IBENS), École Normale Supérieure, CNRS, INSERM, Université PSL, Paris, France
| | - Léa Wolff
- Institut de Biologie de l'École Normale Supérieure (IBENS), École Normale Supérieure, CNRS, INSERM, Université PSL, Paris, France
| | - Antoine Fort
- Dept. of Veterinary and Microbial Sciences, Technological University of The Shannon: Midlands, Athlone, Co., Roscommon, Ireland
| | - Michal Krzyszton
- Laboratory of Seeds Molecular Biology, Institute of Biochemistry and Biophysics, PAS, Warsaw, 02-106, Poland
| | - Jesús López Corrales
- Molecular Parasitology Laboratory (MPL), Centre for One Health and Ryan Institute, School of Natural Sciences, University of Galway, Galway, H91 DK59, Ireland
| | - Szymon Swiezewski
- Laboratory of Seeds Molecular Biology, Institute of Biochemistry and Biophysics, PAS, Warsaw, 02-106, Poland
| | - Fredy Barneche
- Institut de Biologie de l'École Normale Supérieure (IBENS), École Normale Supérieure, CNRS, INSERM, Université PSL, Paris, France
| | - Daniel Schubert
- Institute of Biology, Freie Universität Berlin, 14195, Berlin, Germany
| | - Sara Farrona
- School of Biological and Chemical Sciences, College of Science and Engineering, University of Galway, H91 TK33, Galway, Ireland.
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Iqbal A, Aslam S, Akhtar S, Ali Q, Rao AQ, Husnain T. Over-expression of GhACTIN1 under the control of GhSCFP promoter improves cotton fiber and yield. Sci Rep 2023; 13:18377. [PMID: 37884648 PMCID: PMC10603119 DOI: 10.1038/s41598-023-45782-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Accepted: 10/24/2023] [Indexed: 10/28/2023] Open
Abstract
Actin dynamics is pivotal in controlling cotton fiber elongation and the onset of secondary wall biosynthesis. We report that overexpression of GhACTIN1 under fiber fiber-specific promoter, GhSCFP, improves cotton fiber length, strength, and micronaire value. However, the effect of transgene has a more positive effect on fiber strength and micronaire value than fiber length. F-actin quantification and cellulose contents measurement in transgenic developing cotton fiber during the elongation phase showed an increase of up to 8.7% and 4.7% respectively. Additionally, physiological factors such as water use efficiency showed no significant change in transgenic cotton lines, while stomatal conductance and photosynthetic rate were significantly increased. Moreover, agronomical data determined that lint percentage (GOT) and seed cotton yield also increased up to 4.6% and 29.5% respectively, in transgenic cotton lines compared to the control lines. Our data demonstrate that the GhACTIN1 gene is a strong candidate gene for cotton fiber and yield improvement.
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Affiliation(s)
- Adnan Iqbal
- Centre of Excellence in Molecular Biology, University of Punjab, 87 West Canal Road, Lahore, 53700, Pakistan.
- Plant Breeding and Acclimatization Institute-National Research Institute, Radzikow, 05-870, Blonie, Poland.
| | - Sibgha Aslam
- Plant Breeding and Acclimatization Institute-National Research Institute, Radzikow, 05-870, Blonie, Poland
| | - Sidra Akhtar
- Centre of Excellence in Molecular Biology, University of Punjab, 87 West Canal Road, Lahore, 53700, Pakistan
| | - Qurban Ali
- Department of Plant Breeding and Genetics, University of the Punjab, Lahore, Pakistan.
| | - Abdul Qayyum Rao
- Centre of Excellence in Molecular Biology, University of Punjab, 87 West Canal Road, Lahore, 53700, Pakistan
| | - Tayyab Husnain
- Centre of Excellence in Molecular Biology, University of Punjab, 87 West Canal Road, Lahore, 53700, Pakistan
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Itoh RD, Nakajima KP, Sasaki S, Ishikawa H, Kazama Y, Abe T, Fujiwara MT. TGD5 is required for normal morphogenesis of non-mesophyll plastids, but not mesophyll chloroplasts, in Arabidopsis. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2021; 107:237-255. [PMID: 33884686 DOI: 10.1111/tpj.15287] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Revised: 04/10/2021] [Accepted: 04/13/2021] [Indexed: 06/12/2023]
Abstract
Stromules are dynamic membrane-bound tubular structures that emanate from plastids. Stromule formation is triggered in response to various stresses and during plant development, suggesting that stromules may have physiological and developmental roles in these processes. Despite the possible biological importance of stromules and their prevalence in green plants, their exact roles and formation mechanisms remain unclear. To explore these issues, we obtained Arabidopsis thaliana mutants with excess stromule formation in the leaf epidermis by microscopy-based screening. Here, we characterized one of these mutants, stromule biogenesis altered 1 (suba1). suba1 forms plastids with severely altered morphology in a variety of non-mesophyll tissues, such as leaf epidermis, hypocotyl epidermis, floral tissues, and pollen grains, but apparently normal leaf mesophyll chloroplasts. The suba1 mutation causes impaired chloroplast pigmentation and altered chloroplast ultrastructure in stomatal guard cells, as well as the aberrant accumulation of lipid droplets and their autophagic engulfment by the vacuole. The causal defective gene in suba1 is TRIGALACTOSYLDIACYLGLYCEROL5 (TGD5), which encodes a protein putatively involved in the endoplasmic reticulum (ER)-to-plastid lipid trafficking required for the ER pathway of thylakoid lipid assembly. These findings suggest that a non-mesophyll-specific mechanism maintains plastid morphology. The distinct mechanisms maintaining plastid morphology in mesophyll versus non-mesophyll plastids might be attributable, at least in part, to the differential contributions of the plastidial and ER pathways of lipid metabolism between mesophyll and non-mesophyll plastids.
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Affiliation(s)
- Ryuuichi D Itoh
- Department of Chemistry, Biology and Marine Science, Faculty of Science, University of the Ryukyus, Senbaru 1, Nishihara, Okinawa, 903-0213, Japan
| | - Kohdai P Nakajima
- Department of Chemistry, Biology and Marine Science, Faculty of Science, University of the Ryukyus, Senbaru 1, Nishihara, Okinawa, 903-0213, Japan
| | - Shun Sasaki
- Department of Materials and Life Sciences, Faculty of Science and Technology, Sophia University, 7-1 Kioicho, Chiyoda, Tokyo, 102-8554, Japan
| | - Hiroki Ishikawa
- Department of Materials and Life Sciences, Faculty of Science and Technology, Sophia University, 7-1 Kioicho, Chiyoda, Tokyo, 102-8554, Japan
| | - Yusuke Kazama
- Nishina Center, RIKEN, Wako, Saitama, 351-0198, Japan
| | - Tomoko Abe
- Nishina Center, RIKEN, Wako, Saitama, 351-0198, Japan
| | - Makoto T Fujiwara
- Department of Materials and Life Sciences, Faculty of Science and Technology, Sophia University, 7-1 Kioicho, Chiyoda, Tokyo, 102-8554, Japan
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Yu Y, Jiang Y, Wang L, Wu Y, Liao J, Zhong M, Yang R, Chen X, Li Q, Zhang L. Comparative transcriptome analysis reveals key insights into male sterility in Salvia miltiorrhiza Bunge. PeerJ 2021; 9:e11326. [PMID: 33987012 PMCID: PMC8086568 DOI: 10.7717/peerj.11326] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2020] [Accepted: 03/31/2021] [Indexed: 11/20/2022] Open
Abstract
Background Large-scale heterosis breeding depends upon stable, inherited male sterility lines. We accidentally discovered a male sterility line (SW-S) in the F1progeny of a Salvia miltiorrhiza Bunge from Shandong, China (purple flowers) crossed with a S. miltiorrhiza f. alba from Sichuan, China (white flowers). We sought to provide insights into the pollen development for male sterility in S. miltiorrhiza. Methods The phenotypic and cytological features of the SW-S and fertile control SW-F were observed using scanning electron microscopy and paraffin sections to identify the key stage of male sterility. Transcriptome profiles were recorded for anthers at the tetrad stage of SW-S and SW-F using Illumina RNA-Seq. Results The paraffin sections showed that sterility mainly occurred at the tetrad stage of microspore development, during which the tapetum cells in the anther compartment completely fell off and gradually degraded in the sterile line. There was little-to-no callose deposited around the microspore cells. The tetrad microspore was shriveled and had abnormal morphology. Therefore, anthers at the tetrad stage of SW-S and fertile control SW-F were selected for comparative transcriptome analysis. In total, 266,722,270 clean reads were obtained from SW-S and SW-F, which contained 36,534 genes. There were 2,571 differentially expressed genes (DEGs) in SW-S and SW-F, of which 63.5% were downregulated. Gene Ontology (GO) enrichment analysis indicated that the differentially expressed genes were enriched in 56 functional groups (GO terms); of these, all DEGs involved in microgametogenesis and developmental maturation were downregulated in SW-S. These results were confirmed by quantitative RT-PCR. The two GO terms contained 18 DEGs, among which eight DEGs (namely: GPAT3, RHF1A, phosphatidylinositol, PFAS, MYB96, MYB78, Cals5, and LAT52) were related to gamete development. There were 10 DEGs related to development and maturation, among which three genes were directly related to pollen development (namely: ACT3, RPK2, and DRP1C). Therefore, we believe that these genes are directly or indirectly involved in the pollen abortion of SW-S. Our study provides insight into key genes related to sterility traits in S. miltiorrhiza, and the results can be further exploited in functional and mechanism studies.
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Affiliation(s)
- Yan Yu
- College of Sciences, Sichuan Agricultural University, Ya'an, Sichuan, China.,College of Life Science, China West Normal University, Nanchong, Sichuan, China
| | - Yuanyuan Jiang
- College of Sciences, Sichuan Agricultural University, Ya'an, Sichuan, China
| | - Long Wang
- College of Sciences, Sichuan Agricultural University, Ya'an, Sichuan, China
| | - Yichao Wu
- College of Life Science, China West Normal University, Nanchong, Sichuan, China
| | - Jinqiu Liao
- College of Life Science, Sichuan Agricultural University, Ya'an, Sichuan, China
| | - Mingzhi Zhong
- College of Sciences, Sichuan Agricultural University, Ya'an, Sichuan, China
| | - Ruiwu Yang
- College of Life Science, Sichuan Agricultural University, Ya'an, Sichuan, China
| | - Xingfu Chen
- College of Agronomy, Sichuan Agricultural University, Wenjiang, Sichuan, China
| | - Qingmiao Li
- Sichuan Provincial Key Laboratory of Quality and Innovation Research of Chinese Materia Medica, Sichuan Academy of Chinese Medicine Sciences, Chengdu, Sichuan, China
| | - Li Zhang
- College of Sciences, Sichuan Agricultural University, Ya'an, Sichuan, China
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6
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Patzke K, Prananingrum P, Klemens PAW, Trentmann O, Rodrigues CM, Keller I, Fernie AR, Geigenberger P, Bölter B, Lehmann M, Schmitz-Esser S, Pommerrenig B, Haferkamp I, Neuhaus HE. The Plastidic Sugar Transporter pSuT Influences Flowering and Affects Cold Responses. PLANT PHYSIOLOGY 2019; 179:569-587. [PMID: 30482788 PMCID: PMC6426421 DOI: 10.1104/pp.18.01036] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2018] [Accepted: 11/13/2018] [Indexed: 05/06/2023]
Abstract
Sucrose (Suc) is one of the most important types of sugars in plants, serving inter alia as a long-distance transport molecule, a carbon and energy storage compound, an osmotically active solute, and fuel for many anabolic reactions. Suc biosynthesis and degradation pathways are well known; however, the regulation of Suc intracellular distribution is poorly understood. In particular, the cellular function of chloroplast Suc reserves and the transporters involved in accumulating these substantial Suc levels remain uncharacterized. Here, we characterize the plastidic sugar transporter (pSuT) in Arabidopsis (Arabidopsis thaliana), which belongs to a subfamily of the monosaccharide transporter-like family. Transport analyses with yeast cells expressing a truncated, vacuole-targeted version of pSuT indicate that both glucose and Suc act as substrates, and nonaqueous fractionation supports a role for pSuT in Suc export from the chloroplast. The latter process is required for a correct transition from vegetative to reproductive growth and influences inflorescence architecture. Moreover, pSuT activity affects freezing-induced electrolyte release. These data further underline the central function of the chloroplast for plant development and the modulation of stress tolerance.
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Affiliation(s)
- Kathrin Patzke
- Plant Physiology, University of Kaiserslautern, D-67653 Kaiserslautern, Germany
| | | | - Patrick A W Klemens
- Plant Physiology, University of Kaiserslautern, D-67653 Kaiserslautern, Germany
| | - Oliver Trentmann
- Plant Physiology, University of Kaiserslautern, D-67653 Kaiserslautern, Germany
| | | | - Isabel Keller
- Plant Physiology, University of Kaiserslautern, D-67653 Kaiserslautern, Germany
| | - Alisdair R Fernie
- Max Planck Institut for Molecular Plant Physiology, Wissenschaftspark Golm, D-14476 Potsdam, Germany
| | - Peter Geigenberger
- Ludwig Maximilians University Munich, Biocenter, Department II, D-82152 Planegg-Martinsried, Germany
| | - Bettina Bölter
- Ludwig Maximilians University Munich, Biocenter, Department II, D-82152 Planegg-Martinsried, Germany
| | - Martin Lehmann
- Ludwig Maximilians University Munich, Biocenter, Department II, D-82152 Planegg-Martinsried, Germany
| | | | | | - Ilka Haferkamp
- Plant Physiology, University of Kaiserslautern, D-67653 Kaiserslautern, Germany
| | - H Ekkehard Neuhaus
- Plant Physiology, University of Kaiserslautern, D-67653 Kaiserslautern, Germany
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Zhao J, Missihoun TD, Bartels D. The ATAF1 transcription factor is a key regulator of aldehyde dehydrogenase 7B4 (ALDH7B4) gene expression in Arabidopsis thaliana. PLANTA 2018; 248:1017-1027. [PMID: 30027414 DOI: 10.1007/s00425-018-2955-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Accepted: 07/15/2018] [Indexed: 05/16/2023]
Abstract
ALDH7B4 expression contributes to abiotic stress tolerance. The NAC transcription factor ATAF1 is a main regulator of expression of the ALDH7B4 gene in Arabidopsis thaliana as shown by ATAF1 mutants. The aldehyde dehydrogenase 7B4 (ALDH7B4) protein has important roles in detoxification of excessive aldehydes, elimination of reactive oxygen species (ROS) and inhibition of lipid peroxidation when plants are exposed to abiotic stress. However, the regulation of the expression of the ALDH7B4 gene under stress is largely unknown. Promoter studies revealed crucial cis-elements in the ALDH7B4 promoter in response to heat and stress combinations. Using a yeast one-hybrid assay, several NAC transcription factors, including ATAF1 were isolated. These transcription factors play an important role in plant adaptation to abiotic stress. ATAF1 activates the expression of the ALDH7B4 gene by directly binding to the promoter. Overexpression of ATAF1 in Arabidopsis plants results in elevated expression of ALDH7B4 in seeds, seedlings, and mature plants, whereas ATAF1 knock-out mutant plants abolished the expression of ALDH7B4. This study implies that ATAF1 may confer stress tolerance by up-regulating the target gene ALDH7B4.
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Affiliation(s)
- Junyi Zhao
- Institute of Molecular Physiology and Biotechnology of Plants (IMBIO), University of Bonn, Kirschallee 1, 53115, Bonn, Germany
| | - Tagnon D Missihoun
- Institute of Molecular Physiology and Biotechnology of Plants (IMBIO), University of Bonn, Kirschallee 1, 53115, Bonn, Germany
- Department of Microbiology and Plant Pathology, University of California Riverside, Riverside, CA, 92521, USA
| | - Dorothea Bartels
- Institute of Molecular Physiology and Biotechnology of Plants (IMBIO), University of Bonn, Kirschallee 1, 53115, Bonn, Germany.
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Samira R, Li B, Kliebenstein D, Li C, Davis E, Gillikin JW, Long TA. The bHLH transcription factor ILR3 modulates multiple stress responses in Arabidopsis. PLANT MOLECULAR BIOLOGY 2018; 97:297-309. [PMID: 29882068 DOI: 10.1007/s11103-018-0735-8] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Accepted: 05/05/2018] [Indexed: 05/21/2023]
Abstract
ILR3 and PYE function in a regulatory network that modulates GLS accumulation under iron deficiency. The molecular processes involved in the cross talk between iron (Fe) homeostasis and other metabolic processes in plants are poorly understood. In Arabidopsis thaliana the transcription factor IAA-LEUCINE RESISTANT3 (ILR3) regulates iron deficiency response, aliphatic glucosinolate (GLS) biosynthesis and pathogen response. ILR3 is also known to interact with its homolog, POPEYE (PYE), which also plays a role in Fe response. However, little is known about how ILR3 regulates such diverse processes, particularly, via its interaction with PYE. Since GLS are produced as part of a defense mechanism against wounding pathogens, we examined pILR3::β-GLUCURONIDASE expression and found that Fe deficiency enhances the wound-induced expression of ILR3 in roots and that ILR3 is induced in response to the wounding pathogen, sugarbeet root cyst nematode (Heterodera schachtii). We also examined the expression pattern of genes involved in Fe homeostasis and aliphatic GLS biosynthesis in pye-1, ilr3-2 and pye-1xilr3-2 (pxi) mutants and found that ILR3 and PYE differentially regulate the expression of genes involved these processes under Fe deficiency. We measured GLS levels and sugarbeet root cyst nematode infection rates under varying Fe conditions, and found that long-chain GLS levels are elevated in ilr3-2 and pxi mutants. This increase in long-chain GLS accumulation is correlated with elevated nematode resistance in ilr3-2 and pxi mutants in the absence of Fe. Our findings suggest that ILR3 and PYE function in a regulatory network that controls wounding pathogen response in plant roots by modulating GLS accumulation under iron deficiency.
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Affiliation(s)
- Rozalynne Samira
- Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC, 27695, USA
| | - Baohua Li
- Department of Plant Sciences, University of California, Davis, CA, 95616, USA
| | - Daniel Kliebenstein
- Department of Plant Sciences, University of California, Davis, CA, 95616, USA
- DynaMo Center, Copenhagen Plant Science Centre, Department of Plant and Environmental Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Chunying Li
- Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC, 27695, USA
| | - Eric Davis
- Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC, 27695, USA
| | - Jeffrey W Gillikin
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, NC, 27695, USA
| | - Terri A Long
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, NC, 27695, USA.
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Khan S, ur Rahman L. Pathway Modulation of Medicinal and Aromatic Plants Through Metabolic Engineering Using Agrobacterium tumefaciens. REFERENCE SERIES IN PHYTOCHEMISTRY 2017. [DOI: 10.1007/978-3-319-28669-3_15] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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10
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Goettel W, Ramirez M, Upchurch RG, An YQC. Identification and characterization of large DNA deletions affecting oil quality traits in soybean seeds through transcriptome sequencing analysis. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2016; 129:1577-93. [PMID: 27179525 PMCID: PMC4943983 DOI: 10.1007/s00122-016-2725-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2015] [Accepted: 04/28/2016] [Indexed: 05/11/2023]
Abstract
KEY MESSAGE Identification and characterization of a 254-kb genomic deletion on a duplicated chromosome segment that resulted in a low level of palmitic acid in soybean seeds using transcriptome sequencing. A large number of soybean genotypes varying in seed oil composition and content have been identified. Understanding the molecular mechanisms underlying these variations is important for breeders to effectively utilize them as a genetic resource. Through design and application of a bioinformatics approach, we identified nine co-regulated gene clusters by comparing seed transcriptomes of nine soybean genotypes varying in oil composition and content. We demonstrated that four gene clusters in the genotypes M23, Jack and N0304-303-3 coincided with large-scale genome rearrangements. The co-regulated gene clusters in M23 and Jack mapped to a previously described 164-kb deletion and a copy number amplification of the Rhg1 locus, respectively. The coordinately down-regulated gene clusters in N0304-303-3 were caused by a 254-kb deletion containing 19 genes including a fatty acyl-ACP thioesterase B gene (FATB1a). This deletion was associated with reduced palmitic acid content in seeds and was the molecular cause of a previously reported nonfunctional FATB1a allele, fap nc . The M23 and N0304-304-3 deletions were located in duplicated genome segments retained from the Glycine-specific whole genome duplication that occurred 13 million years ago. The homoeologous genes in these duplicated regions shared a strong similarity in both their encoded protein sequences and transcript accumulation levels, suggesting that they may have conserved and important functions in seeds. The functional conservation of homoeologous genes may result in genetic redundancy and gene dosage effects for their associated seed traits, explaining why the large deletion did not cause lethal effects or completely eliminate palmitic acid in N0304-303-3.
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Affiliation(s)
- Wolfgang Goettel
- US Department of Agriculture, Agricultural Research Service, Midwest Area, Plant Genetics Research Unit, Donald Danforth Plant Science Center, 975 N. Warson Rd, St. Louis, MO, 63132, USA
| | - Martha Ramirez
- US Department of Agriculture, Agricultural Research Service, Soybean and Nitrogen Fixation Research, 2417 Gardner Hall, Raleigh, NC, 27695, USA
| | - Robert G Upchurch
- US Department of Agriculture, Agricultural Research Service, Soybean and Nitrogen Fixation Research, 2417 Gardner Hall, Raleigh, NC, 27695, USA
| | - Yong-Qiang Charles An
- US Department of Agriculture, Agricultural Research Service, Midwest Area, Plant Genetics Research Unit, Donald Danforth Plant Science Center, 975 N. Warson Rd, St. Louis, MO, 63132, USA.
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11
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Huang J, Smith AR, Zhang T, Zhao D. Creating Completely Both Male and Female Sterile Plants by Specifically Ablating Microspore and Megaspore Mother Cells. FRONTIERS IN PLANT SCIENCE 2016; 7:30. [PMID: 26870055 PMCID: PMC4740954 DOI: 10.3389/fpls.2016.00030] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2015] [Accepted: 01/10/2016] [Indexed: 05/20/2023]
Abstract
Although genetically modified (GM) plants have improved commercially important traits, such as biomass and biofuel production, digestibility, bioremediation, ornamental value, and tolerance to biotic and abiotic stresses, there remain economic, political, or social concerns over potential ecological effects of transgene flow from GM plants. The current solution for preventing transgene flow from GM plants is genetically engineering sterility; however, approaches to generating both male and female sterility are limited. In addition, existing strategies for creating sterility lead to loss or modifications of entire flowers or floral organs. Here, we demonstrate that instead of the 1.5-kb promoter, the entire SOLO DANCERS (SDS) gene is required for its meiocyte-specific expression. We then developed an efficient method to specifically ablate microspore and megaspore mother cells using the SDS and BARNASE fusion gene, which resulted in complete sterility in both male and female reproductive organs in Arabidopsis (Arabidopsis thaliana) and tobacco (Nicotiana tabacum), but did not affect plant growth or development, including the formation of all flower organs. Therefore, our research provides a general and effective tool to prevent transgene flow in GM plants.
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Chang M, Huang S. Arabidopsis ACT11 modifies actin turnover to promote pollen germination and maintain the normal rate of tube growth. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2015; 83:515-527. [PMID: 26096143 DOI: 10.1111/tpj.12910] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Revised: 05/21/2015] [Accepted: 06/01/2015] [Indexed: 06/04/2023]
Abstract
Actin is an ancient conserved protein that is encoded by multiple isovariants in multicellular organisms. There are eight functional actin genes in the Arabidopsis genome, and the precise function and mechanism of action of each isovariant remain poorly understood. Here, we report the characterization of ACT11, a reproductive actin isovariant. Our studies reveal that loss of function of ACT11 causes a delay in pollen germination, but enhances pollen tube growth. Cytological analysis revealed that the amount of filamentous actin decreased, and the rate of actin turnover increased in act11 pollen. Convergence of actin filaments upon the germination aperture was impaired in act11 pollen, consistent with the observed delay of germination. Reduction of actin dynamics with jasplakinolide suppressed the germination and tube growth phenotypes in act11 pollen, suggesting that the underlying mechanisms involve an increase in actin dynamics. Thus, we demonstrate that ACT11 is required to maintain the rate of actin turnover in order to promote pollen germination and maintain the normal rate of pollen tube growth.
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Affiliation(s)
- Ming Chang
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Shanjin Huang
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing, 100084, China
- National Center for Plant Gene Research, Beijing, 100101, China
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Gunning PW, Ghoshdastider U, Whitaker S, Popp D, Robinson RC. The evolution of compositionally and functionally distinct actin filaments. J Cell Sci 2015; 128:2009-19. [DOI: 10.1242/jcs.165563] [Citation(s) in RCA: 157] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
ABSTRACT
The actin filament is astonishingly well conserved across a diverse set of eukaryotic species. It has essentially remained unchanged in the billion years that separate yeast, Arabidopsis and man. In contrast, bacterial actin-like proteins have diverged to the extreme, and many of them are not readily identified from sequence-based homology searches. Here, we present phylogenetic analyses that point to an evolutionary drive to diversify actin filament composition across kingdoms. Bacteria use a one-filament-one-function system to create distinct filament systems within a single cell. In contrast, eukaryotic actin is a universal force provider in a wide range of processes. In plants, there has been an expansion of the number of closely related actin genes, whereas in fungi and metazoa diversification in tropomyosins has increased the compositional variety in actin filament systems. Both mechanisms dictate the subset of actin-binding proteins that interact with each filament type, leading to specialization in function. In this Hypothesis, we thus propose that different mechanisms were selected in bacteria, plants and metazoa, which achieved actin filament compositional variation leading to the expansion of their functional diversity.
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Affiliation(s)
- Peter W. Gunning
- School of Medical Sciences, University of New South Wales, Sydney, NSW, 2052, Australia
| | - Umesh Ghoshdastider
- Institute of Molecular and Cell Biology, A*STAR (Agency for Science, Technology and Research), Biopolis, Singapore 138673
| | - Shane Whitaker
- School of Medical Sciences, University of New South Wales, Sydney, NSW, 2052, Australia
| | - David Popp
- Institute of Molecular and Cell Biology, A*STAR (Agency for Science, Technology and Research), Biopolis, Singapore 138673
| | - Robert C. Robinson
- Institute of Molecular and Cell Biology, A*STAR (Agency for Science, Technology and Research), Biopolis, Singapore 138673
- Department of Biochemistry, National University of Singapore, 8 Medical Drive, Singapore 117597
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Selote D, Samira R, Matthiadis A, Gillikin JW, Long TA. Iron-binding E3 ligase mediates iron response in plants by targeting basic helix-loop-helix transcription factors. PLANT PHYSIOLOGY 2015; 167:273-86. [PMID: 25452667 PMCID: PMC4281009 DOI: 10.1104/pp.114.250837] [Citation(s) in RCA: 186] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2014] [Accepted: 11/27/2014] [Indexed: 05/18/2023]
Abstract
Iron uptake and metabolism are tightly regulated in both plants and animals. In Arabidopsis (Arabidopsis thaliana), BRUTUS (BTS), which contains three hemerythrin (HHE) domains and a Really Interesting New Gene (RING) domain, interacts with basic helix-loop-helix transcription factors that are capable of forming heterodimers with POPEYE (PYE), a positive regulator of the iron deficiency response. BTS has been shown to have E3 ligase capacity and to play a role in root growth, rhizosphere acidification, and iron reductase activity in response to iron deprivation. To further characterize the function of this protein, we examined the expression pattern of recombinant ProBTS::β-GLUCURONIDASE and found that it is expressed in developing embryos and other reproductive tissues, corresponding with its apparent role in reproductive growth and development. Our findings also indicate that the interactions between BTS and PYE-like (PYEL) basic helix-loop-helix transcription factors occur within the nucleus and are dependent on the presence of the RING domain. We provide evidence that BTS facilitates 26S proteasome-mediated degradation of PYEL proteins in the absence of iron. We also determined that, upon binding iron at the HHE domains, BTS is destabilized and that this destabilization relies on specific residues within the HHE domains. This study reveals an important and unique mechanism for plant iron homeostasis whereby an E3 ubiquitin ligase may posttranslationally control components of the transcriptional regulatory network involved in the iron deficiency response.
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Affiliation(s)
- Devarshi Selote
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, North Carolina 27695
| | - Rozalynne Samira
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, North Carolina 27695
| | - Anna Matthiadis
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, North Carolina 27695
| | - Jeffrey W Gillikin
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, North Carolina 27695
| | - Terri A Long
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, North Carolina 27695
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15
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Kiefer CS, Claes AR, Nzayisenga JC, Pietra S, Stanislas T, Hüser A, Ikeda Y, Grebe M. Arabidopsis AIP1-2 restricted by WER-mediated patterning modulates planar polarity. Development 2014; 142:151-61. [PMID: 25428588 PMCID: PMC4299142 DOI: 10.1242/dev.111013] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The coordination of cell polarity within the plane of the tissue layer (planar polarity) is crucial for the development of diverse multicellular organisms. Small Rac/Rho-family GTPases and the actin cytoskeleton contribute to planar polarity formation at sites of polarity establishment in animals and plants. Yet, upstream pathways coordinating planar polarity differ strikingly between kingdoms. In the root of Arabidopsis thaliana, a concentration gradient of the phytohormone auxin coordinates polar recruitment of Rho-of-plant (ROP) to sites of polar epidermal hair initiation. However, little is known about cytoskeletal components and interactions that contribute to this planar polarity or about their relation to the patterning machinery. Here, we show that ACTIN7 (ACT7) represents a main actin isoform required for planar polarity of root hair positioning, interacting with the negative modulator ACTIN-INTERACTING PROTEIN1-2 (AIP1-2). ACT7, AIP1-2 and their genetic interaction are required for coordinated planar polarity of ROP downstream of ethylene signalling. Strikingly, AIP1-2 displays hair cell file-enriched expression, restricted by WEREWOLF (WER)-dependent patterning and modified by ethylene and auxin action. Hence, our findings reveal AIP1-2, expressed under control of the WER-dependent patterning machinery and the ethylene signalling pathway, as a modulator of actin-mediated planar polarity. Summary: Planar polarity in Arabidopsis is shaped by ACTIN-INTERACTING PROTEIN1-2, which is under the control of WEREWOLF-dependent patterning and ethylene signalling.
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Affiliation(s)
- Christian S Kiefer
- Umeå Plant Science Centre, Department of Plant Physiology, Umeå University, Umeå SE-90 187, Sweden
| | - Andrea R Claes
- Umeå Plant Science Centre, Department of Plant Physiology, Umeå University, Umeå SE-90 187, Sweden
| | - Jean-Claude Nzayisenga
- Umeå Plant Science Centre, Department of Plant Physiology, Umeå University, Umeå SE-90 187, Sweden
| | - Stefano Pietra
- Umeå Plant Science Centre, Department of Plant Physiology, Umeå University, Umeå SE-90 187, Sweden
| | - Thomas Stanislas
- Umeå Plant Science Centre, Department of Plant Physiology, Umeå University, Umeå SE-90 187, Sweden
| | - Anke Hüser
- Umeå Plant Science Centre, Department of Plant Physiology, Umeå University, Umeå SE-90 187, Sweden
| | - Yoshihisa Ikeda
- Umeå Plant Science Centre, Department of Plant Physiology, Umeå University, Umeå SE-90 187, Sweden
| | - Markus Grebe
- Umeå Plant Science Centre, Department of Plant Physiology, Umeå University, Umeå SE-90 187, Sweden Institute of Biochemistry and Biology, Plant Physiology, University of Potsdam, Karl-Liebknecht-Str. 24-25, Building 20, Potsdam-Golm D-14476, Germany
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Lin L, Tian S, Kaeppler S, Liu Z, An YQ(C. Conserved transcriptional regulatory programs underlying rice and barley germination. PLoS One 2014; 9:e87261. [PMID: 24558366 PMCID: PMC3928125 DOI: 10.1371/journal.pone.0087261] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2012] [Accepted: 12/24/2013] [Indexed: 11/18/2022] Open
Abstract
Germination is a biological process important to plant development and agricultural production. Barley and rice diverged 50 million years ago, but share a similar germination process. To gain insight into the conservation of their underlying gene regulatory programs, we compared transcriptomes of barley and rice at start, middle and end points of germination, and revealed that germination regulated barley and rice genes (BRs) diverged significantly in expression patterns and/or protein sequences. However, BRs with higher protein sequence similarity tended to have more conserved expression patterns. We identified and characterized 316 sets of conserved barley and rice genes (cBRs) with high similarity in both protein sequences and expression patterns, and provided a comprehensive depiction of the transcriptional regulatory program conserved in barley and rice germination at gene, pathway and systems levels. The cBRs encoded proteins involved in a variety of biological pathways and had a wide range of expression patterns. The cBRs encoding key regulatory components in signaling pathways often had diverse expression patterns. Early germination up-regulation of cell wall metabolic pathway and peroxidases, and late germination up-regulation of chromatin structure and remodeling pathways were conserved in both barley and rice. Protein sequence and expression pattern of a gene change quickly if it is not subjected to a functional constraint. Preserving germination-regulated expression patterns and protein sequences of those cBRs for 50 million years strongly suggests that the cBRs are functionally significant and equivalent in germination, and contribute to the ancient characteristics of germination preserved in barley and rice. The functional significance and equivalence of the cBR genes predicted here can serve as a foundation to further characterize their biological functions and facilitate bridging rice and barley germination research with greater confidence.
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Affiliation(s)
- Li Lin
- USDA-ARS, Plant Genetics Research Unit, Donald Danforth Plant Sciences Center, Saint Louis, Missouri, United States of America
- Department of Agronomy, University of Wisconsin, Wisconsin, United States of America
| | - Shulan Tian
- USDA-ARS, Plant Genetics Research Unit, Donald Danforth Plant Sciences Center, Saint Louis, Missouri, United States of America
- Department of Plant Pathology, University of Wisconsin, Madison, Wisconsin, United States of America
| | - Shawn Kaeppler
- Department of Agronomy, University of Wisconsin, Wisconsin, United States of America
| | - Zongrang Liu
- USDA-ARS, Appalachian Fruit Research Station, Kearneysville, West Virginia, United States of America
| | - Yong-Qiang (Charles) An
- USDA-ARS, Plant Genetics Research Unit, Donald Danforth Plant Sciences Center, Saint Louis, Missouri, United States of America
- * E-mail:
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Dillon SK, Brawner JT, Meder R, Lee DJ, Southerton SG. Association genetics in Corymbia citriodora subsp. variegata identifies single nucleotide polymorphisms affecting wood growth and cellulosic pulp yield. THE NEW PHYTOLOGIST 2012; 195:596-608. [PMID: 22680066 DOI: 10.1111/j.1469-8137.2012.04200.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Wood is an important biological resource which contributes to nutrient and hydrology cycles through ecosystems, and provides structural support at the plant level. Thousands of genes are involved in wood development, yet their effects on phenotype are not well understood. We have exploited the low genomic linkage disequilibrium (LD) and abundant phenotypic variation of forest trees to explore allelic diversity underlying wood traits in an association study. Candidate gene allelic diversity was modelled against quantitative variation to identify SNPs influencing wood properties, growth and disease resistance across three populations of Corymbia citriodora subsp. variegata, a forest tree of eastern Australia. Nine single nucleotide polymorphism (SNP) associations from six genes were identified in a discovery population (833 individuals). Associations were subsequently tested in two smaller populations (130-160 individuals), 'validating' our findings in three cases for actin 7 (ACT7) and COP1 interacting protein 7 (CIP7). The results imply a functional role for these genes in mediating wood chemical composition and growth, respectively. A flip in the effect of ACT7 on pulp yield between populations suggests gene by environment interactions are at play. Existing evidence of gene function lends strength to the observed associations, and in the case of CIP7 supports a role in cortical photosynthesis.
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Affiliation(s)
- Shannon K Dillon
- CSIRO Plant Industry, GPO Box 1600 Canberra, ACT 2601, Australia
| | - Jeremy T Brawner
- CSIRO Plant Industry, 306 Carmody Road, St Lucia, QLD 4067, Australia
| | - Roger Meder
- CSIRO Plant Industry, 306 Carmody Road, St Lucia, QLD 4067, Australia
- University of the Sunshine Coast Faculty of Science, Health, Education and Engineering, Maroochydore, QLD 4558, Australia
| | - David J Lee
- University of the Sunshine Coast Faculty of Science, Health, Education and Engineering, Maroochydore, QLD 4558, Australia
- Department of Employment Economic Development and Innovation, 1 Cartwright Road, Gympie, QLD 4570, Australia
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Šlajcherová K, Fišerová J, Fischer L, Schwarzerová K. Multiple actin isotypes in plants: diverse genes for diverse roles? FRONTIERS IN PLANT SCIENCE 2012; 3:226. [PMID: 23091476 PMCID: PMC3469877 DOI: 10.3389/fpls.2012.00226] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2012] [Accepted: 09/21/2012] [Indexed: 05/07/2023]
Abstract
Plant actins are encoded by a gene family. Despite the crucial significance of the actin cytoskeleton for plant structure and function, the importance of individual actin isotypes and their specific roles in various plant tissues or even single cells is rather poorly understood. This review summarizes our current knowledge about the plant actin gene family including its evolution, gene and protein structure, and the expression profiles and regulation. Based on this background information, we review mutant and complementation analyses in Arabidopsis to draw an emerging picture of overlapping and specific roles of plant actin isotypes. Finally, we examine hypotheses explaining the mechanisms of isotype-specific functions.
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Affiliation(s)
- Kateřina Šlajcherová
- Faculty of Science, Department of Experimental Plant Biology, Charles University in PraguePrague, Czech Republic
| | - Jindřiška Fišerová
- Faculty of Science, Department of Experimental Plant Biology, Charles University in PraguePrague, Czech Republic
| | - Lukáš Fischer
- Faculty of Science, Department of Experimental Plant Biology, Charles University in PraguePrague, Czech Republic
| | - Kateřina Schwarzerová
- Faculty of Science, Department of Experimental Plant Biology, Charles University in PraguePrague, Czech Republic
- *Correspondence: Kateřina Schwarzerová, Faculty of Science, Department of Experimental Plant Biology, Charles University in Prague, Vinicná 5, Prague 128 44, Czech Republic. e-mail:
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Fujiwara MT, Yoshioka Y, Hirano T, Kazama Y, Abe T, Hayashi K, Itoh RD. Visualization of plastid movement in the pollen tube of Arabidopsis thaliana. PLANT SIGNALING & BEHAVIOR 2012; 7:34-7. [PMID: 22301964 PMCID: PMC3357363 DOI: 10.4161/psb.7.1.18484] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Organelle dynamics in the plant male gametophyte has received attention for its importance in pollen tube growth and cytoplasmic inheritance. We recently revealed the dynamic behaviors of plastids in living Arabidopsis pollen grains and tubes, using an inherent promoter-driven FtsZ1-green fluorescent protein (GFP) fusion. Here, we further monitored the movement of pollen tube plastids with an actin1 promoter-driven, stroma-targeted yellow fluorescent protein (YFP). In elongating pollen tubes, most plastids localized to the tube shank, where they displayed either retarded and unsteady motion, or fast, directional, and long-distance movement along the tube polarity. Efficient plastid tracking further revealed a population of tip-forwarding plastids that undergo a fluctuating motion(s) before traveling backwards. The behavior of YFP-labeled plastids in pollen basically resembled that of FtsZ1-GFP-labeled plastids, thus validating the use of FtsZ1-GFP for simultaneous visualization of the stroma and the plastid-dividing FtsZ ring.
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Affiliation(s)
- Makoto T Fujiwara
- Department of Materials and Life Sciences, Sophia University, Tokyo, Japan.
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20
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An YQ, Lin L. Transcriptional regulatory programs underlying barley germination and regulatory functions of Gibberellin and abscisic acid. BMC PLANT BIOLOGY 2011; 11:105. [PMID: 21668981 PMCID: PMC3130657 DOI: 10.1186/1471-2229-11-105] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2010] [Accepted: 06/13/2011] [Indexed: 05/07/2023]
Abstract
BACKGROUND Seed germination is a complex multi-stage developmental process, and mainly accomplished through concerted activities of many gene products and biological pathways that are often subjected to strict developmental regulation. Gibberellins (GA) and abscisic acid (ABA) are two key phytohormones regulating seed germination and seedling growth. However, transcriptional regulatory networks underlying seed germination and its associated biological pathways are largely unknown. RESULTS The studies examined transcriptomes of barley representing six distinct and well characterized germination stages and revealed that the transcriptional regulatory program underlying barley germination was composed of early, late, and post-germination phases. Each phase was accompanied with transcriptional up-regulation of distinct biological pathways. Cell wall synthesis and regulatory components including transcription factors, signaling and post-translational modification components were specifically and transiently up-regulated in early germination phase while histone families and many metabolic pathways were up-regulated in late germination phase. Photosynthesis and seed reserve mobilization pathways were up-regulated in post-germination phase. However, stress related pathways and seed storage proteins were suppressed through the entire course of germination. A set of genes were transiently up-regulated within three hours of imbibition, and might play roles in initiating biological pathways involved in seed germination. However, highly abundant transcripts in dry barley and Arabidopsis seeds were significantly conserved. Comparison with transcriptomes of barley aleurone in response to GA and ABA identified three sets of germination responsive genes that were regulated coordinately by GA, antagonistically by ABA, and coordinately by GA but antagonistically by ABA. Major CHO metabolism, cell wall degradation and protein degradation pathways were up-regulated by both GA and seed germination. Those genes and metabolic pathways are likely to be important parts of transcriptional regulatory networks underlying GA and ABA regulation of seed germination and seedling growth. CONCLUSIONS The studies developed a model depicting transcriptional regulatory programs underlying barley germination and GA and ABA regulation of germination at gene, pathway and systems levels, and established a standard transcriptome reference for further integration with various -omics and biological data to illustrate biological networks underlying seed germination. The studies also generated a great amount of systems biological evidence for previously proposed hypotheses, and developed a number of new hypotheses on transcriptional regulation of seed germination for further experimental validation.
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Affiliation(s)
- Yong-Qiang An
- US Department of Agriculture, Agriculture Research Service, Midwest Area, Plant Genetics Research at Donald Danforth Plant Sciences Center; 975 N Warson Road, St. Louis, MO 63132, USA
| | - Li Lin
- 221 Morrill Science Center III, Department of Biology University of Massachusetts, 611 N. Pleasant St., Amherst, MA 01003, USA
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Oh DH, Dassanayake M, Haas JS, Kropornika A, Wright C, d'Urzo MP, Hong H, Ali S, Hernandez A, Lambert GM, Inan G, Galbraith DW, Bressan RA, Yun DJ, Zhu JK, Cheeseman JM, Bohnert HJ. Genome structures and halophyte-specific gene expression of the extremophile Thellungiella parvula in comparison with Thellungiella salsuginea (Thellungiella halophila) and Arabidopsis. PLANT PHYSIOLOGY 2010; 154:1040-52. [PMID: 20833729 PMCID: PMC2971586 DOI: 10.1104/pp.110.163923] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
The genome of Thellungiella parvula, a halophytic relative of Arabidopsis (Arabidopsis thaliana), is being assembled using Roche-454 sequencing. Analyses of a 10-Mb scaffold revealed synteny with Arabidopsis, with recombination and inversion and an uneven distribution of repeat sequences. T. parvula genome structure and DNA sequences were compared with orthologous regions from Arabidopsis and publicly available bacterial artificial chromosome sequences from Thellungiella salsuginea (previously Thellungiella halophila). The three-way comparison of sequences, from one abiotic stress-sensitive species and two tolerant species, revealed extensive sequence conservation and microcolinearity, but grouping Thellungiella species separately from Arabidopsis. However, the T. parvula segments are distinguished from their T. salsuginea counterparts by a pronounced paucity of repeat sequences, resulting in a 30% shorter DNA segment with essentially the same gene content in T. parvula. Among the genes is SALT OVERLY SENSITIVE1 (SOS1), a sodium/proton antiporter, which represents an essential component of plant salinity stress tolerance. Although the SOS1 coding region is highly conserved among all three species, the promoter regions show conservation only between the two Thellungiella species. Comparative transcript analyses revealed higher levels of basal as well as salt-induced SOS1 expression in both Thellungiella species as compared with Arabidopsis. The Thellungiella species and other halophytes share conserved pyrimidine-rich 5' untranslated region proximal regions of SOS1 that are missing in Arabidopsis. Completion of the genome structure of T. parvula is expected to highlight distinctive genetic elements underlying the extremophile lifestyle of this species.
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Affiliation(s)
- Dong-Ha Oh
- Department of Plant Biology , University of Illinois, Urbana, Illinois 61801, USA.
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Desai PN, Shrivastava N, Padh H. Production of heterologous proteins in plants: strategies for optimal expression. Biotechnol Adv 2010; 28:427-35. [PMID: 20152894 DOI: 10.1016/j.biotechadv.2010.01.005] [Citation(s) in RCA: 167] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2009] [Revised: 01/01/2010] [Accepted: 01/25/2010] [Indexed: 11/25/2022]
Abstract
Plants are a promising expression system for the production of heterologous proteins, especially therapeutic proteins. Currently the majority of therapeutic proteins are produced in mammalian cell lines or bacteria. In a few cases insects, yeast and fungi have been developed for production of human proteins. However, these expression systems have limitations in terms of suitability, cost, scalability, purification and post-translational modifications. Therefore, alternative expression systems are being developed in transgenic animals and transgenic plants. Transgenic plants could provide an attractive alternative in terms of low production cost and lower capital investment in infrastructure, and with appropriate post-translational modifications. The potential of plants as an expression host has not been capitalized, primarily due to lower level of expression of transgenes in plants. The present review will evaluate the rate limiting steps of plant expression systems and suggest strategies to optimize protein expression at each of the steps: gene integration, transcription, translation and protein accumulation.
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Affiliation(s)
- Priti N Desai
- B. V. Patel Pharmaceutical Education and Research Development Centre, Ahmedabad, India
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Tamada Y, Yun JY, Woo SC, Amasino RM. ARABIDOPSIS TRITHORAX-RELATED7 is required for methylation of lysine 4 of histone H3 and for transcriptional activation of FLOWERING LOCUS C. THE PLANT CELL 2009; 21:3257-69. [PMID: 19855050 PMCID: PMC2782277 DOI: 10.1105/tpc.109.070060] [Citation(s) in RCA: 148] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2009] [Revised: 09/04/2009] [Accepted: 09/16/2009] [Indexed: 05/18/2023]
Abstract
In the winter-annual accessions of Arabidopsis thaliana, presence of an active allele of FRIGIDA (FRI) elevates expression of FLOWERING LOCUS C (FLC), a repressor of flowering, and thus confers a vernalization requirement. FLC activation by FRI involves methylation of Lys 4 of histone H3 (H3K4) at FLC chromatin. Many multicellular organisms that have been examined contain two classes of H3K4 methylases, a yeast (Saccharomyces cerevisiae) Set1 class and a class related to Drosophila melanogaster Trithorax. In this work, we demonstrate that ARABIDOPSIS TRITHORAX-RELATED7 (ATXR7), a putative Set1 class H3K4 methylase, is required for proper FLC expression. The atxr7 mutation partially suppresses the delayed flowering of a FRI-containing line. The rapid flowering of atxr7 is associated with reduced FLC expression and is accompanied by decreased H3K4 methylation and increased H3K27 methylation at FLC. Thus, ATXR7 is required for the proper levels of these histone modifications that set the level of FLC expression to create a vernalization requirement in winter-annual accessions. Previously, it has been reported that lesions in ATX1, which encodes a Trithorax class H3K4 methylase, partially suppress the delayed flowering of winter-annual Arabidopsis. We show that the flowering phenotype of atx1 atxr7 double mutants is additive relative to those of single mutants. Therefore, both classes of H3K4 methylases appear to be required for proper regulation of FLC expression.
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Peng H, Cheng H, Yu X, Shi Q, Zhang H, Li J, Ma H. Molecular analysis of an actin gene, CarACT1, from chickpea (Cicer arietinum L.). Mol Biol Rep 2009; 37:1081-8. [DOI: 10.1007/s11033-009-9844-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2009] [Accepted: 09/15/2009] [Indexed: 11/28/2022]
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Iwano M, Entani T, Shiba H, Kakita M, Nagai T, Mizuno H, Miyawaki A, Shoji T, Kubo K, Isogai A, Takayama S. Fine-tuning of the cytoplasmic Ca2+ concentration is essential for pollen tube growth. PLANT PHYSIOLOGY 2009; 150:1322-34. [PMID: 19474213 PMCID: PMC2705041 DOI: 10.1104/pp.109.139329] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2009] [Accepted: 05/20/2009] [Indexed: 05/17/2023]
Abstract
Pollen tube growth is crucial for the delivery of sperm cells to the ovule during flowering plant reproduction. Previous in vitro imaging of Lilium longiflorum and Nicotiana tabacum has shown that growing pollen tubes exhibit a tip-focused Ca(2+) concentration ([Ca(2+)]) gradient and regular oscillations of the cytosolic [Ca(2+)] ([Ca(2+)](cyt)) in the tip region. Whether this [Ca(2+)] gradient and/or [Ca(2+)](cyt) oscillations are present as the tube grows through the stigma (in vivo condition), however, is still not clear. We monitored [Ca(2+)](cyt) dynamics in pollen tubes under various conditions using Arabidopsis (Arabidopsis thaliana) and N. tabacum expressing yellow cameleon 3.60, a fluorescent calcium indicator with a large dynamic range. The tip-focused [Ca(2+)](cyt) gradient was always observed in growing pollen tubes. Regular oscillations of the [Ca(2+)](cyt), however, were rarely identified in Arabidopsis or N. tabacum pollen tubes grown under the in vivo condition or in those placed in germination medium just after they had grown through a style (semi-in vivo condition). On the other hand, regular oscillations were observed in vitro in both growing and nongrowing pollen tubes, although the oscillation amplitude was 5-fold greater in the nongrowing pollen tubes compared with growing pollen tubes. These results suggested that a submicromolar [Ca(2+)](cyt) in the tip region is essential for pollen tube growth, whereas a regular [Ca(2+)] oscillation is not. Next, we monitored [Ca(2+)] dynamics in the endoplasmic reticulum ([Ca(2+)](ER)) in relation to Arabidopsis pollen tube growth using yellow cameleon 4.60, which has a lower affinity for Ca(2+) compared with yellow cameleon 3.60. The [Ca(2+)](ER) in pollen tubes grown under the semi-in vivo condition was between 100 and 500 microm. In addition, cyclopiazonic acid, an inhibitor of ER-type Ca(2+)-ATPases, inhibited growth and decreased the [Ca(2+)](ER). Our observations suggest that the ER serves as one of the Ca(2+) stores in the pollen tube and cyclopiazonic acid-sensitive Ca(2+)-ATPases in the ER are required for pollen tube growth.
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Affiliation(s)
- Megumi Iwano
- Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma, Nara 630-0101, Japan.
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Long TA, Okegawa Y, Shikanai T, Schmidt GW, Covert SF. Conserved role of proton gradient regulation 5 in the regulation of PSI cyclic electron transport. PLANTA 2008; 228:907-18. [PMID: 18663471 DOI: 10.1007/s00425-008-0789-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2008] [Accepted: 07/07/2008] [Indexed: 05/02/2023]
Abstract
There are at least two photosynthetic cyclic electron transport (CET) pathways in most C(3) plants: the NAD(P)H dehydrogenase (NDH)-dependent pathway and a pathway dependent upon putative ferredoxin:plastoquinone oxidoreductase (FQR) activity. While the NDH complex has been identified, and shown to play a role in photosynthesis, especially under stress conditions, less is known about the machinery of FQR-dependent CET. Recent studies indicate that FQR-dependent CET is dependent upon PGR5, a small protein of unknown function. In a previous study we found that overexpression of PGR5 causes alterations in growth and development associated with decreased chloroplast development and a transient increase in nonphotochemical quenching (NPQ) after the shift from dark to light. In the current study we examine the spatiotemporal expression pattern of PGR5, and the effects of overexpression of PGR5 in Arabidopsis under a host of light and stress conditions. To investigate the conserved function of PGR5, we cloned PGR5 from a species which apparently lacks NDH, loblolly pine, and overexpressed it in Arabidopsis. Although greening of cotyledons was severely delayed in overexpressing lines under low light, mature plants survived exposure to high light and drought stress better than wild-type. In addition, PSI was more resistant to high light in the PGR5 overexpressors than in wild-type plants, while PSII was more sensitive to this stress. These complex responses corresponded to alterations in linear and cyclic electron transfer, suggesting that over-accumulation of PGR5 induces pleiotropic effects, probably via elevated CET. We conclude that PGR5 has a developmentally-regulated, conserved role in mediating CET.
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Affiliation(s)
- Terri A Long
- Department of Genetics, University of Georgia, Athens, GA 30602, USA.
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Meagher RB, Kandasamy MK, McKinney EC. Multicellular development and protein-protein interactions. PLANT SIGNALING & BEHAVIOR 2008; 3:333-6. [PMID: 19841663 PMCID: PMC2634275 DOI: 10.4161/psb.3.5.5343] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2007] [Accepted: 11/28/2007] [Indexed: 05/20/2023]
Abstract
The macroevolution of organs and tissues in higher plants and animals may have been contingent upon the expansion of numerous gene families encoding interacting proteins. For example, there are dozens of gene families encoding actin cytoskeletal proteins that elaborate intercellular structures influencing development. Once gene family members evolve compartmentalized expression, protein isovariants are free to coevolve new interacting partners that may be incompatible with other related protein networks. Ancient classes of actin isovariants and actin-binding proteins are clear examples of such coevolving networks. Ectopic expression and suppression studies were used to dissect these interactions. In higher plants, the ectopic expression of a reproductive actin isovariant in vegetative cell types causes aberrant reorganization of the F-actin cytoskeleton and bizarre development of most organs and tissues. In contrast, overexpression of vegetative actin in vegetative cell types has little effect. The extreme ectopic actin expression phenotypes are suppressed by the coectopic expression of reproductive profilin or actin depolymerizing factor (ADF/cofilin) isovariants, but not by the overexpression of vegetative profilin or ADF. These data provide evidence for the coevolution of organ-specific protein-protein interactions. Thus, understanding the contingent relationships between the evolution of organ-specific isovariant networks and organ origination may be key to explaining multicellular development.
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Affiliation(s)
- Richard B Meagher
- Department of Genetics; Davison Life Sciences Building; University of Georgia; Athens, Georgia USA
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Pawloski LC, Kandasamy MK, Meagher RB. The late pollen actins are essential for normal male and female development in Arabidopsis. PLANT MOLECULAR BIOLOGY 2006; 62:881-96. [PMID: 17031513 DOI: 10.1007/s11103-006-9063-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2006] [Accepted: 07/19/2006] [Indexed: 05/12/2023]
Abstract
In angiosperms the late pollen actins (LPAs) are strongly expressed in mature pollen and pollen tubes and at much lower levels in ovules. Four Arabidopsis lines with homozygous knockout mutations in the four individual LPA genes displayed normal flowers, pollen, and seed set. However, when all four LPAs were silenced simultaneously with a single RNA interference (RNAi) construct targeting the 3'UTR of each mRNA, obvious reproductive defects were observed. Western analysis of various Late Pollen actin RNA interference (LPRi) epialleles showed total LPA protein and RNA expression levels were knocked down from 0% to 95% compared to wild-type levels. Reciprocal crosses with the RNAi lines demonstrated that lowered LPA expression was associated with defects in both male and female fertility. Strong epialleles showed significant reductions in normal silique and seed production and were nearly sterile. Dissection of the siliques from moderate LPRi epialleles revealed many unfertilized ovules, increased numbers of aborted seeds, and decreased numbers of healthy seeds. Microscopic analysis of LPRi pollen indicated that the pollen shape and size were normal, but pollen germinated poorly. While multiple LPA genes may have some functional redundancy, the combined expression of multiple LPA genes appears essential to normal male and female reproductive development.
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Affiliation(s)
- Lucia Cardenas Pawloski
- Department of Genetics, Life Sciences Building, University of Georgia, Athens, GA 30602, USA
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A Triticum tauschii protein kinase related to wheat PKABA1 is associated with ABA signaling and is distributed between the nucleus and cytosol. J Cereal Sci 2005. [DOI: 10.1016/j.jcs.2004.11.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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31
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Li XB, Fan XP, Wang XL, Cai L, Yang WC. The cotton ACTIN1 gene is functionally expressed in fibers and participates in fiber elongation. THE PLANT CELL 2005; 17:859-75. [PMID: 15722467 PMCID: PMC1069704 DOI: 10.1105/tpc.104.029629] [Citation(s) in RCA: 239] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2004] [Accepted: 12/27/2004] [Indexed: 05/17/2023]
Abstract
Single-celled cotton fiber (Gossypium hirsutum) provides a unique experimental system to study cell elongation. To investigate the role of the actin cytoskeleton during fiber development, 15 G. hirsutum ACTIN (GhACT) cDNA clones were characterized. RNA gel blot and real-time RT-PCR analysis revealed that GhACT genes are differentially expressed in different tissues and can be classified into four groups. One group, represented by GhACT1, is expressed predominantly in fiber cells and was studied in detail. A 0.8-kb GhACT1 promoter sufficient to confirm its fiber-specific expression was identified. RNA interference of GhACT1 caused significant reduction of its mRNA and protein levels and disrupted the actin cytoskeleton network in fibers. No defined actin network was observed in these fibers and, consequently, fiber elongation was inhibited. Our results suggested that GhACT1 plays an important role in fiber elongation but not fiber initiation.
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Affiliation(s)
- Xue-Bao Li
- College of Life Sciences, Central China Normal University, Wuhan 430079, China.
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Berrin JG, Pierrugues O, Brutesco C, Alonso B, Montillet JL, Roby D, Kazmaier M. Stress induces the expression of AtNADK-1, a gene encoding a NAD(H) kinase in Arabidopsis thaliana. Mol Genet Genomics 2005; 273:10-9. [PMID: 15711971 DOI: 10.1007/s00438-005-1113-1] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2004] [Accepted: 12/22/2004] [Indexed: 11/30/2022]
Abstract
A novel Arabidopsis thaliana gene (AtNADK-1) was identified based on its response to radiation and oxidative stress. Levels of AtNADK-1 mRNA increase eight-fold following exposure to ionising radiation and are enhanced three-fold by treatment with hydrogen peroxide. The gene also appears to be differentially regulated during compatible and incompatible plant-pathogen interactions in response to Pseudomonas syringae pv. tomato. The full-length AtNADK-1 cDNA encodes a 58-kDa protein that shows high sequence homology to the recently defined family of NAD(H) kinases. Recombinant AtNADK-1 utilises ATP to phosphorylate both NAD and NADH, showing a two-fold preference for NADH. Using reverse genetics, we demonstrate that AtNADK-1 deficient plants display enhanced sensitivity to gamma irradiation and to paraquat-induced oxidative stress. Our results indicate that this novel NAD(H) kinase may contribute to the maintenance of redox status in Arabidopsis thaliana.
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Affiliation(s)
- Jean-Guy Berrin
- Département d'Ecophysiologie Végétale et de Microbiologie, Laboratoire de Bioénergétique Cellulaire, CEA Cadarache, Bât 156, 13108 Saint-Paul Lez Durance, France
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Iwano M, Shiba H, Miwa T, Che FS, Takayama S, Nagai T, Miyawaki A, Isogai A. Ca2+ dynamics in a pollen grain and papilla cell during pollination of Arabidopsis. PLANT PHYSIOLOGY 2004; 136:3562-71. [PMID: 15489279 PMCID: PMC527155 DOI: 10.1104/pp.104.046961] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2004] [Revised: 08/08/2004] [Accepted: 08/09/2004] [Indexed: 05/20/2023]
Abstract
Ca2+ dynamics in the growing pollen tube have been well documented in vitro using germination assays and Ca2+ imaging techniques. However, very few in vivo studies of Ca2+ in the pollen grain and papilla cell during pollination have been performed. We expressed yellow cameleon, a Ca2+ indicator based on green fluorescent protein, in the pollen grains and papilla cells of Arabidopsis (Arabidopsis thaliana) and monitored Ca2+ dynamics during pollination. In the pollen grain, [Ca2+]cyt increased at the potential germination site soon after hydration and remained augmented until germination. As in previous in vitro germination studies, [Ca2+]cyt oscillations were observed in the tip region of the growing pollen tube, but the oscillation frequency was faster and [Ca2+]cyt was higher than had been observed in vitro. In the pollinated papilla cell, remarkable increases in [Ca2+]cyt occurred three times in succession, just under the site of pollen-grain attachment. [Ca2+]cyt increased first soon after pollen hydration, with a second increase occurring after pollen protrusion. The third and most remarkable [Ca2+]cyt increase took place when the pollen tube penetrated into the papilla cell wall.
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Affiliation(s)
- Megumi Iwano
- Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma, Nara 630-0101, Japan.
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Diet A, Brunner S, Ringli C. The enl mutants enhance the lrx1 root hair mutant phenotype of Arabidopsis thaliana. PLANT & CELL PHYSIOLOGY 2004; 45:734-741. [PMID: 15215508 DOI: 10.1093/pcp/pch084] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The development of root hairs serves as an excellent model to study cell growth using both cytological and genetic approaches. In the past, we have characterized LRX1, an extracellular protein of Arabidopsis consisting of an LRR-domain and a structural extensin domain. LRX1 is specifically expressed in root hairs and lrx1 mutants show severe deficiencies in root hair development. In this work, we describe the characterization of enl (enhancer of lrx1) mutants that were isolated in a visual screen of an ethylmethanesulfonate -mutagenized lrx1 line for plants exhibiting an enhanced lrx1 phenotype. Four recessive enl mutants were analyzed, three of which define new genetic loci involved in root hair development. The mutations at the enl loci and lrx1 result in additive phenotypes in enl/lrx1 double mutants. One enl mutant is affected in the ACTIN2 gene and encodes a protein with a 22 amino acid deletion at the C-terminus. The comparison of molecular and phenotypic data of different actin2 alleles suggests that the truncated ACTIN2 protein is still partially functional.
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Affiliation(s)
- Anouck Diet
- Institute of Plant Biology, University of Zürich, Zollikerstrasse 107, CH-8008, Switzerland
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35
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Dean G, Casson S, Lindsey K. KNAT6 gene of Arabidopsis is expressed in roots and is required for correct lateral root formation. PLANT MOLECULAR BIOLOGY 2004; 54:71-84. [PMID: 15159635 DOI: 10.1023/b:plan.0000028772.22892.2d] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
As part of a programme to determine whether root development requires a pathway involving KNOTTED-like homeobox ( KNOX ) genes, we cloned the KNAT6 cDNA, a member of the KNOX gene family in Arabidopsis, from root tissue. The KNAT6 cDNA is represented by two isoforms, suggesting that the KNAT6 transcript is subject to alternative splicing. Promoter-reporter and RT-PCR analysis confirms expression of the KNAT6 gene in roots, and in particular in the phloem tissue close to the site of lateral root initiation, though not in the primary or lateral root meristem. The KNAT6 gene promoter activity is altered in pattern by treatment with exogenous auxin and in the rooty mutant background, with expression shifting distally in the root. In contrast, exogenous cytokinin suppresses KNAT6 promoter activity. KNAT6::GFP fusion protein is localized to the nucleus, consistent with the predicted function of KNAT6 as a transcription factor. Over-expression of the more abundant shorter isoform of the KNAT6 cDNA, but not of the less abundant longer form, leads to a lobed leaf phenotype, but no consistently aberrant root phenotype. Down-regulation of KNAT6 expression by RNA interference was associated with an increased total number of lateral roots. These data indicate a role for KNAT6 in modulating lateral root formation.
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Affiliation(s)
- Gillian Dean
- Botany Department, University of British Columbia, 6270 University Boulevard, Vancouver, BC, Canada V6T 1Z4
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36
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Abstract
In the past decade the first Arabidopsis genes encoding cytoskeletal proteins were identified. A few dozen genes in the actin and tubulin cytoskeletal systems have been characterized thoroughly, including gene families encoding actins, profilins, actin depolymerizing factors, α-tubulins, and β-tubulins. Conventional molecular genetics have shown these family members to be differentially expressed at the temporal and spatial levels with an ancient split separating those genes expressed in vegetative tissues from those expressed in reproductive tissues. A few members of other cytoskeletal gene families have also been partially characterized, including an actin-related protein, annexins, fimbrins, kinesins, myosins, and villins. In the year 2001 the Arabidopsis genome sequence was completed. Based on sequence homology with well-characterized animal, fungal, and protist sequences, we find candidate cytoskeletal genes in the Arabidopsis database: more than 150 actin-binding proteins (ABPs), including monomer binding, capping, cross-linking, attachment, and motor proteins; more than 200 microtubule-associated proteins (MAPs); and, surprisingly, 10 to 40 potential intermediate filament (IF) proteins. Most of these sequences are uncharacterized and were not identified as related to cytoskeletal proteins. Several Arabidopsis ABPs, MAPs, and IF proteins are represented by individual genes and most were represented as as small gene families. However, several classes of cytoskeletal genes including myosin, eEF1α, CLIP, tea1, and kinesin are part of large gene families with 20 to 70 potential gene members each. This treasure trove of data provides an unprecedented opportunity to make rapid advances in understanding the complex plant cytoskeletal proteome. However, the functional analysis of these proposed cytoskeletal proteins and their mutants will require detailed analysis at the cell biological, molecular genetic, and biochemical levels. New approaches will be needed to move more efficiently and rapidly from this mass of DNA sequence to functional studies on cytoskeletal proteins.
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Affiliation(s)
- Richard B. Meagher
- Department of Genetics, University of Georgia, Athens, GA 30602,
; phone: 706 542-1444; fax: 706 542-1387
| | - Marcus Fechheimer
- Department of Cellular Biology, University of Georgia, Athens, GA 30602,
; phone: 706 542-3338; fax: 706 542-4271
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Falbel TG, Koch LM, Nadeau JA, Segui-Simarro JM, Sack FD, Bednarek SY. SCD1 is required for cytokinesis and polarized cell expansion in Arabidopsis thaliana [corrected]. Development 2003; 130:4011-24. [PMID: 12874123 DOI: 10.1242/dev.00619] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
In the leaf epidermis, guard mother cells undergo a stereotyped symmetric division to form the guard cells of stomata. We have identified a temperature-sensitive Arabidopsis mutant, stomatal cytokinesis-defective 1-1 (scd1-1), which affects this specialized division. At the non-permissive temperature, 22 degrees C, defective scd1-1 guard cells are binucleate, and the formation of their ventral cell walls is incomplete. Cytokinesis was also disrupted in other types of epidermal cells such as pavement cells. Further phenotypic analysis of scd1-1 indicated a role for SCD1 in seedling growth, root elongation and flower morphogenesis. More severe scd1 T-DNA insertion alleles (scd1-2 and scd1-3) markedly affect polar cell expansion, most notably in trichomes and root hairs. SCD1 is a unique gene in Arabidopsis that encodes a protein related to animal proteins that regulate intracellular protein transport and/or mitogen-activated protein kinase signaling pathways. Consistent with a role for SCD1 in membrane trafficking, secretory vesicles were found to accumulate in cytokinesis-defective scd1 cells. In addition the scd1 mutant phenotype was enhanced by low doses of inhibitors of cell plate consolidation and vesicle secretion. We propose that SCD1 functions in polarized vesicle trafficking during plant cytokinesis and cell expansion.
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Affiliation(s)
- Tanya G Falbel
- Department of Biochemistry, University of Wisconsin-Madison, 433 Babcock Drive, Madison, WI 53706, USA
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Vitale A, Wu RJ, Cheng Z, Meagher RB. Multiple conserved 5' elements are required for high-level pollen expression of the Arabidopsis reproductive actin ACT1. PLANT MOLECULAR BIOLOGY 2003; 52:1135-51. [PMID: 14682614 DOI: 10.1023/b:plan.0000004309.06973.16] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
The Arabidopsis thaliana actin gene family comprises eight genes, which are divided into two ancient classes, vegetative and reproductive. We dissected various 5' elements and the conserved expression pattern of the reproductive actin gene ACT1, which is the most strongly expressed pollen actin gene. A basal construct containing only 310 bp of sequence upstream of the major transcriptional start site showed essentially full promoter activity in pollen and ovules. Further truncations of the 5'-flanking region and two different 10 bp replacements within a 55 bp conserved domain each caused a several-fold reduction in mature pollen expression. Intron L, located in the 5'-untranslated region (5'-UTR) was also required for high-level expression of pollen and organ primordia, and it had the properties of an enhancer. Pollen expression was not preserved when intron L was precisely replaced by intron L2 from the vegetatively expressed actin gene ACT2. ACT1 reporter gene constructs were strongly expressed in both pollen and ovules of tobacco and in the pollen of rice. Promoter-reporter fusions of the most distantly related Arabidopsis reproductive actin gene ACT1 showed strong expression in tobacco pollen and ovules indistinguishable from that directed by ACT1. Thus, multiple conserved cis-sequence elements within the 5'-flanking region and 5'-UTR of ACT1 direct high levels of reproductive tissue-specific expression.
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Affiliation(s)
- Angela Vitale
- Department of Physiology, Tufts University School of Medicine, Boston, MA 02111-1800, USA
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Barth I, Meyer S, Sauer N. PmSUC3: characterization of a SUT2/SUC3-type sucrose transporter from Plantago major. THE PLANT CELL 2003; 15:1375-85. [PMID: 12782730 PMCID: PMC156373 DOI: 10.1105/tpc.010967] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2003] [Accepted: 04/10/2003] [Indexed: 05/18/2023]
Abstract
Higher plants possess medium-sized gene families that encode plasma membrane-localized sucrose transporters. For several plant species, it has been shown that at least one of these genes (e.g., AtSUC3 in Arabidopsis and LeSUT2 in tomato) differs from all other family members in several features, such as the length of the open reading frame, the number of introns, and the codon usage bias. For these reasons, and because two of these proteins did not rescue a yeast mutant defective in sucrose utilization, it had been speculated that this subgroup of transporters might have sensor functions. Here, we describe the detailed functional characterization and cellular localization of PmSUC3, the orthologous transporter from the Plantago major transporter family. The PmSUC3 protein is localized in the sieve elements of the Plantago phloem and mediates the energy-dependent transport of sucrose and maltose. In contrast to the situation in solanaceous plants, PmSUC3 is not colocalized with PmSUC2, the source-specific, phloem-loading sucrose transporter of Plantago. Moreover, PmSUC3 also was identified in sieve elements of sink leaves and in several nonphloem cells and tissues. Arguments for and against a potential sensor function for this type of sucrose transporter are presented, and the role of this type of transporter in the regulation of sucrose fluxes is discussed.
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Affiliation(s)
- Inga Barth
- Molekulare Pflanzenphysiologie, Universität Erlangen-Nürnberg, D-91058 Erlangen, Germany
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40
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Despres B, Bouissonnié F, Wu HJ, Gomord V, Guilleminot J, Grellet F, Berger F, Delseny M, Devic M. Three SAC1-like genes show overlapping patterns of expression in Arabidopsis but are remarkably silent during embryo development. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2003; 34:293-306. [PMID: 12713536 DOI: 10.1046/j.1365-313x.2003.01720.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
In Saccharomyces cerevisiae, the SAC1 gene encodes a polyphosphoinositide phosphatase (PPIPase) that modulates the levels of phosphoinositides, which are key regulators of a number of signal transduction processes. SAC1p has been implicated in multiple cellular functions: actin cytoskeleton organization, secretory functions, inositol metabolism, ATP transport, and multiple-drug sensitivity. Here, we describe the characterization of three genes in Arabidopsis thaliana, AtSAC1a, AtSAC1b, and AtSAC1c, encoding proteins similar to those of yeast SAC1p. We demonstrated that the three AtSAC1 proteins are functional homologs of the yeast SAC1p because they can rescue the cold-sensitive and inositol auxotroph yeast sac1-null mutant strain. The fact that Arabidopsis and yeast SAC1 genes derived from a common ancestor suggests that this plant multigenic family is involved in the phosphoinositide pathway and in a range of cellular functions similar to those in yeast. Using GFP fusion experiments, we demonstrate that the three AtSAC1 proteins are targeted to the endoplasmic reticulum. Their expression patterns are overlapping, with at least two members expressed in each organ. Remarkably, AtSAC1 genes are not expressed during seed development, and therefore additional phosphatases are required to control phosphoinositide levels in seeds.
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Affiliation(s)
- Barbara Despres
- Laboratoire Génome et Développement des Plantes, UMR CNRS 5096, Université de Perpignan, 52 Avenue de Villeneuve, France
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Dos Santos CV, Letousey P, Delavault P, Thalouarn P. Defense Gene Expression Analysis of Arabidopsis thaliana Parasitized by Orobanche ramosa. PHYTOPATHOLOGY 2003; 93:451-457. [PMID: 18944360 DOI: 10.1094/phyto.2003.93.4.451] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
ABSTRACT The infection of Arabidopsis thaliana roots with the obligate parasite Orobanche ramosa represents a useful model for a study of the molecular events involved in the host plant response to a parasitic plant attack. To avoid analysis problems due to the subterranean development of O. ramosa, we developed two in vitro co-culture systems: O. ramosa seedlings infesting Arabidopsis plantlet roots and callus tissues. We were then able to investigate the expression patterns of some host plant genes selected among genes known to be involved in metabolic pathways and resistance mechanisms activated during several plant-pathogen interactions including ethylene, isoprenoid, phenylpropanoid, and jasmonate biosynthesis pathways, oxidative stress responses, and pathogenesis-related proteins. Molecular analyses were carried out using polymerase chain reaction amplification methods allowing semiquantitative evaluation of transcript accumulation during early (first hours) and late (15 days) stages of infestation, in whole roots or parts close to the parasite attachment site. In A. thaliana, O. ramosa induced most of the general response signaling pathways in a transient manner even before its attachment to A. thaliana roots. However, no salicylic acid-dependent defense is observed because no activation of systemic acquired resistance markers is detectable, whereas genes, co-regulated by jasmonate and ethylene, do display enhanced expression.
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42
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Zhang XD, Jenkins JN, Callahan FE, Creech RG, Si Y, McCarty JC, Saha S, Ma DP. Molecular cloning, differential expression, and functional characterization of a family of class I ubiquitin-conjugating enzyme (E2) genes in cotton (Gossypium). BIOCHIMICA ET BIOPHYSICA ACTA 2003; 1625:269-79. [PMID: 12591614 DOI: 10.1016/s0167-4781(02)00623-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Two cDNAs and their corresponding genes (GhUBC1 and GhUBC2) encoding ubiquitin-conjugating enzymes (E2s) have been cloned and characterized from allotetraploid cotton Gossypium hirsutum ((AD)(1) genome). Three additional E2 genes (GaUBC1, GtUBC2, and GrUBC2) have also been identified from diploid cottons Gossypium arboreum (A(2) genome), Gossypium thurberi (D(1) genome), and Gossypium raimondii (D(5) genome), respectively. The derived amino acid sequences of the five closely related cotton E2s are 77-79% identical to yeast ScUBC4 and ScUBC5. The GhUBC1/2 gene family is composed of two members, and genomic origin analysis indicates that GhUBC1 and 2 are individually present in the A and D subgenomes of G. hirsutum. The transcript levels of GhUBC1/2 increased significantly in leaves and flowers at senescence, suggesting that GhUBC1/2 may play a role in the degradation of target proteins that function in the delay of the senescence program. Correlated with high auxin content and auxin-associated effects, GhUBC1/2 are also highly expressed in the youngest leaves, the apical part of lateral roots, and elongating fibers. Genetic complementation experiments revealed that GhUBC1 and 2 can substitute for the function of ScUBC4 and 5 required for the selective degradation of abnormal and short-lived proteins in a yeast ubc4ubc5 double mutant.
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Affiliation(s)
- Xiang-Dong Zhang
- Department of Biochemistry and Molecular Biology, Box 9650, Mississippi State University, Mississippi State, MS 39762, USA
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Gilliland LU, Pawloski LC, Kandasamy MK, Meagher RB. Arabidopsis actin gene ACT7 plays an essential role in germination and root growth. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2003; 33:319-28. [PMID: 12535345 DOI: 10.1046/j.1365-313x.2003.01626.x] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Arabidopsis contains eight actin genes. Of these ACT7 is the most strongly expressed in young plant tissues and shows the greatest response to physiological cues. Adult plants homozygous for the act7 mutant alleles show no obvious above-ground phenotypes, which suggests a high degree of functional redundancy among plant actins. However, act7-1 mutant plants are at a strong selective disadvantage when grown in competition with wild-type plants and therefore must have undetected physical defects. The act7-1 and act7-4 alleles contain T-DNA insertions just after the stop codon and within the first intron, respectively. Homozygous mutant seedlings of both alleles showed less than 7% of normal ACT7 protein levels. Mutants displayed delayed and less efficient germination, increased root twisting and waving, and retarded root growth. The act7-4 mutant showed the most dramatic reduction in root growth. The act7-4 root apical cells were not in straight files and contained oblique junctions between cells suggesting a possible role for ACT7 in determining cell polarity. Wild-type root growth was fully restored to the act7-1 mutant by the addition of an exogenous copy of the ACT7 gene. T-DNA insertions just downstream of the major polyadenylation sites (act7-2, act7-3) appeared fully wild type. The act7 mutant phenotypes demonstrate a significant requirement for functional ACT7 protein during root development and explain the strong negative selection component seen for the act7-1 mutant.
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Affiliation(s)
- Laura U Gilliland
- Department of Biochemistry, 215 Biochemistry Building, Michigan State University, East Lansing, MI 48824, USA
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Gilliland LU, Kandasamy MK, Pawloski LC, Meagher RB. Both vegetative and reproductive actin isovariants complement the stunted root hair phenotype of the Arabidopsis act2-1 mutation. PLANT PHYSIOLOGY 2002; 130:2199-209. [PMID: 12481103 PMCID: PMC166731 DOI: 10.1104/pp.014068] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2001] [Revised: 09/18/2002] [Accepted: 09/18/2002] [Indexed: 05/17/2023]
Abstract
The ACT2 gene, encoding one of eight actin isovariants in Arabidopsis, is the most strongly expressed actin gene in vegetative tissues. A search was conducted for physical defects in act2-1 mutant plants to account for their reduced fitness compared with wild type in population studies. The act2-1 insertion fully disrupted expression of ACT2 RNA and significantly lowered the level of total actin protein in vegetative organs. The root hairs of the act2-1 mutants were 10% to 70% the length of wild-type root hairs, and they bulged severely at the base. The length of the mutant root hairs and degree of bulging at the base were affected by adjusting the osmolarity and gelling agent of the growth medium. The act2-1 mutant phenotypes were fully rescued by an ACT2 genomic transgene. When the act2-1 mutation was combined with another vegetative actin mutation, act7-1, the resulting double mutant exhibited extensive synergistic phenotypes ranging from developmental lethality to severe dwarfism. Transgenic overexpression of the ACT7 vegetative isovariant and ectopic expression of the ACT1 reproductive actin isovariant also rescued the root hair elongation defects of the act2-1 mutant. These results suggest normal ACT2 gene regulation is essential to proper root hair elongation and that even minor differences may cause root defects. However, differences in the actin protein isovariant are not significant to root hair elongation, in sharp contrast to recent reports on the functional nonequivalency of plant actin isovariants. Impairment of root hair functions such as nutrient mining, water uptake, and physical anchoring are the likely cause of the reduced fitness seen for act2-1 mutants in multigenerational studies.
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Affiliation(s)
- Laura U Gilliland
- Department of Genetics, University of Georgia, Athens, Georgia 30602-7223, USA
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Kim MK, Jeon JH, Davin LB, Lewis NG. Monolignol radical-radical coupling networks in western red cedar and Arabidopsis and their evolutionary implications. PHYTOCHEMISTRY 2002; 61:311-322. [PMID: 12359517 DOI: 10.1016/s0031-9422(02)00261-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The discovery of a nine-member multigene dirigent family involved in control of monolignol radical-radical coupling in the ancient gymnosperm, western red cedar, suggested that a complex multidimensional network had evolved to regulate such processes in vascular plants. Accordingly, in this study, the corresponding promoter regions for each dirigent multigene member were obtained by genome-walking, with Arabidopsis being subsequently transformed to express each promoter fused to the beta-glucuronidase (GUS) reporter gene. It was found that each component gene of the proposed network is apparently differentially expressed in individual tissues, organs and cells at all stages of plant growth and development. The data so obtained thus further support the hypothesis that a sophisticated monolignol radical-radical coupling network exists in plants which has been highly conserved throughout vascular plant evolution.
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Affiliation(s)
- Myoung K Kim
- Institute of Biological Chemistry, Washington State University, Pullman, WA 99164-6340, USA
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Mun JH, Lee SY, Yu HJ, Jeong YM, Shin MY, Kim H, Lee I, Kim SG. Petunia actin-depolymerizing factor is mainly accumulated in vascular tissue and its gene expression is enhanced by the first intron. Gene 2002; 292:233-43. [PMID: 12119118 DOI: 10.1016/s0378-1119(02)00646-7] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Actin-depolymerizing factor (ADF) is one of the actin cytoskeleton-modulating proteins. We have characterized the accumulation pattern of petunia ADF proteins. PhADF proteins are accumulated in every petunia organ and their accumulation is differentially regulated by developmental signals. Their cellular localization is vascular tissue-preferential in vegetative organs, whereas somewhat different in reproductive organs. In reproductive organs, PhADFs are present in outer integument, endocarp of ovary wall, transmitting tissue of style, and epidermis and endothecium of young anther. From a petunia genomic library, we have isolated a genomic clone encoding PhADF1. Comparison to complementary DNA sequence revealed that the coding region of PhADF1 gene consists of three exons and two introns. Analysis of chimeric gene expression using beta-glucuronidase as a reporter gene in transgenic Arabidopsis revealed that PhADF1 was strongly expressed in every vegetative tissue except petal. In addition, expression of the gene was highly enhanced by its first intron. These results suggest that PhADF1 gene of petunia is mainly expressed in vascular tissues and its expression is regulated by intron-mediated enhancement mechanism.
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Affiliation(s)
- Jeong-Hwan Mun
- School of Biological Sciences, Seoul National University, Seoul 151-742, South Korea
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Oyama T, Shimura Y, Okada K. The IRE gene encodes a protein kinase homologue and modulates root hair growth in Arabidopsis. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2002; 30:289-299. [PMID: 12000677 DOI: 10.1046/j.1365-313x.2002.01290.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
We identified an Arabidopsis mutant, incomplete root hair elongation (ire), whose root hairs are about 40% shorter than the wild type owing to the early cessation of their growth. In contrast, the hy5 mutant has root hairs about twice as long as the wild type, possibly because of delayed cessation of growth. Thus IRE and HY5 are likely to modify the duration of growth of root hairs. We cloned the IRE locus using the T-DNA tagged line. The IRE locus encodes a protein that includes a serine/threonine protein kinase domain. The primary structure of this kinase domain shows significant similarity to a group of protein kinases among various eukaryotes. In the Arabidopsis genome there are at least three genes that are closely related to IRE. The IRE transcript was detected in every organ examined. However, the IRE promoter-GUS fusion gene was strongly expressed in the elongating root hair cells, suggesting the cell-autonomous function of IRE in root hairs. GUS activity was also detected in pollen grains, which develop by tip growth, suggesting that IRE has a common role in the tip growth of plant cells.
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Affiliation(s)
- Tokitaka Oyama
- Department of Botany, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
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McKinney EC, Kandasamy MK, Meagher RB. Arabidopsis contains ancient classes of differentially expressed actin-related protein genes. PLANT PHYSIOLOGY 2002; 128:997-1007. [PMID: 11891255 PMCID: PMC152212 DOI: 10.1104/pp.010906] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2001] [Revised: 11/26/2001] [Accepted: 12/10/2001] [Indexed: 05/20/2023]
Abstract
Actin-related proteins (ARPs) share less than 60% amino acid sequence homology with conventional actins and have roles in diverse cytoskeletal processes in the cytoplasm and nucleus. The genome of Arabidopsis was explored for possible ARP gene family members. Eight potential ARP gene sequences were found dispersed on three of the five Arabidopsis chromosomes. AtARP2 and AtARP3 are protein orthologs of their similarly named counterparts in other kingdoms. AtARP4, AtARP5, and AtARP6 are orthologs of two classes of nuclear ARPs previously characterized in animals and fungi, BAF53s and ARP6s. AtARP7 and AtARP8 appear to be novel proteins that are not closely related to any known animal or fungal ARPs, and may be plant specific. The complex Arabidopsis ARP gene structures each contain from five to 20 exons. Expressed transcripts were identified and characterized for AtARP2 through AtARP8, but not for AtARP9, and transcripts representing two splice variants were found for AtARP8. The seven expressed genes are predicted to encode proteins ranging from 146 to 471 amino acids in length. Relative to conventional actin and the other ARPs, AtARP2 and AtARP3 transcripts are expressed at very low levels in all organs. AtARP5, AtARP6, and AtARP8 each have distinct transcript expression patterns in seedlings, roots, leaves, flowers, and siliques. Using isovariant-specific monoclonal antibodies, AtARP4 and AtARP7 proteins were shown to be most highly expressed in flowers. The likely involvement of plant ARPs in actin nucleation, branching of actin filaments, chromatin restructuring, and transcription are briefly discussed.
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Affiliation(s)
- Elizabeth Cohen McKinney
- Genetics Department, Life Sciences Building, University of Georgia, Athens, Georgia 30602-7223, USA
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Lessard PA, Kulaveerasingam H, York GM, Strong A, Sinskey AJ. Manipulating gene expression for the metabolic engineering of plants. Metab Eng 2002; 4:67-79. [PMID: 11800576 DOI: 10.1006/mben.2001.0210] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Introducing and expressing foreign genes in plants present many technical challenges that are not encountered with microbial systems. This review addresses the variety of issues that must be considered and the variety of options that are available, in terms of choosing transformation systems and designing recombinant transgenes to ensure appropriate expression in plant cells. Tissue specificity and proper developmental regulation, as well as proper subcellular localization of products, must be dealt with for successful metabolic engineering in plants..
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Affiliation(s)
- Philip A Lessard
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
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Kandasamy MK, McKinney EC, Meagher RB. Functional nonequivalency of actin isovariants in Arabidopsis. Mol Biol Cell 2002; 13:251-61. [PMID: 11809837 PMCID: PMC65086 DOI: 10.1091/mbc.01-07-0342] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Plants encode at least two ancient and divergent classes of actin, reproductive and vegetative, and each class produces several subclasses of actin isovariants. To gain insight into the functional significance of the actin isovariants, we generated transgenic Arabidopsis lines that expressed a reproductive actin, ACT1, under the control of the regulatory sequences of a vegetative actin gene, ACT2. In the wild-type plants, ACT1 is predominantly expressed in the mature pollen, growing pollen tubes, and ovules, whereas ACT2 is constitutively and strongly expressed in all vegetative tissues and organs, but not in pollen. Misexpression of ACT1 in vegetative tissues causes dwarfing of plants and altered morphology of most organs, and the effects are in direct proportion to protein expression levels. Similar overexpression of ACT2 has little effect. Immunolocalization of actin in leaf cells from transgenic plants with highest levels of ACT1 protein revealed massive polymerization, bundling, and reorganization of actin filaments. This phenomenon suggests that misexpression of ACT1 isovariant in vegetative tissues affects the dynamics of actin and actin-associated proteins, in turn disrupting the organization of actin cytoskeleton and normal development of plants.
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