51
|
Salem MA, Giavalisco P. Regulatory-Associated Protein of TOR 1B (RAPTOR1B) regulates hormonal switches during seed germination in Arabidopsis thaliana. PLANT SIGNALING & BEHAVIOR 2019; 14:1613130. [PMID: 31058576 PMCID: PMC6619983 DOI: 10.1080/15592324.2019.1613130] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Revised: 04/23/2019] [Accepted: 04/26/2019] [Indexed: 06/09/2023]
Abstract
Target of Rapamycin (TOR) regulates multiple growth- and metabolic-related processes in Arabidopsis thaliana as in all other eukaryotes. While several of these processes have been investigated in diverse Arabidopsis growth stages, little is known about hormonal and metabolic regulation of TOR during seed germination. This is mainly due to the fact that Arabidopsis knockout lines of TOR are embryo lethal. Here, we utilized the knockout lines of TOR-interacting protein, REGULATORY-ASSOCIATED PROTEIN OF TOR 1B (RAPTOR1B), to perform comprehensive hormone profiling during seed germination. We previously reported that RAPTOR1B positively regulates seed germination by maintaining the nutritional and hormonal balance. In the current analysis, dry and imbibed seeds as well as germinated seeds were subjected to detailed hormone analysis. Accordingly, the abscisic acid content of dry and imbibed raptor1b seeds was higher than that of WT, while the amounts of gibberellins were comparable after stratification. Further analysis showed that raptor1b seeds maintained higher levels of indole-3-acetic acid and jasmonates, namely jasmonic acid (JA) and 12-oxo-phytodienoic acid, even after stratification. The combination of this hormonal perturbation seems to be the driving factor for the observed delayed germination phenotypes in raptor1b seeds.
Collapse
Affiliation(s)
- Mohamed A. Salem
- Department of Pharmacognosy, Faculty of Pharmacy, Menoufia University, Shibin Elkom, Egypt
- Max Planck Institute of Molecular Plant Physiology, Germany
| | | |
Collapse
|
52
|
MacGregor DR, Zhang N, Iwasaki M, Chen M, Dave A, Lopez‐Molina L, Penfield S. ICE1 and ZOU determine the depth of primary seed dormancy in Arabidopsis independently of their role in endosperm development. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2019; 98:277-290. [PMID: 30570804 PMCID: PMC6900779 DOI: 10.1111/tpj.14211] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2018] [Revised: 11/20/2018] [Accepted: 12/12/2018] [Indexed: 05/06/2023]
Abstract
Seed dormancy is a widespread and key adaptive trait that is essential for the establishment of soil seed banks and prevention of pre-harvest sprouting. Herein we demonstrate that the endosperm-expressed transcription factors ZHOUPI (ZOU) and INDUCER OF CBF EXPRESSION1 (ICE1) play a role in determining the depth of primary dormancy in Arabidopsis. We show that ice1 or zou increases seed dormancy and the double mutant has an additive phenotype. This increased dormancy is associated with increased ABA levels, and can be separated genetically from any role in endosperm maturation because loss of ABA biosynthesis or DELAY OF GERMINATION 1 reverses the dormancy phenotype without affecting the aberrant seed morphology. Consistent with these results, ice1 endosperms had an increased capacity for preventing embryo greening, a phenotype previously associated with an increase in endospermic ABA levels. Although ice1 changes the expression of many genes, including some in ABA biosynthesis, catabolism and/or signalling, only ABA INSENSITIVE 3 is significantly misregulated in ice1 mutants. We also demonstrate that ICE1 binds to and inhibits expression of ABA INSENSITIVE 3. Our data demonstrate that Arabidopsis ICE1 and ZOU determine the depth of primary dormancy during maturation independently of their effect on endosperm development.
Collapse
Affiliation(s)
- Dana R. MacGregor
- Department of Crop GeneticsJohn Innes CentreNorwich Research ParkNorwichNR4 7UHUK
- Present address:
Department of Biointeractions and Crop ProtectionRothamsted ResearchHarpenden, HertfordshireAL5 2JQUK
| | - Naichao Zhang
- Department of Crop GeneticsJohn Innes CentreNorwich Research ParkNorwichNR4 7UHUK
| | - Mayumi Iwasaki
- Department of Plant Biology and Institute for Genetics and Genomics in Geneva (iGE3)University of Geneva30, Quai Ernest‐Ansermet CH‐1211Geneva4Switzerland
| | - Min Chen
- Department of Crop GeneticsJohn Innes CentreNorwich Research ParkNorwichNR4 7UHUK
- Present address:
College of Life Science and TechnologyHuazhong Agricultural UniversityWuhan430070China
| | - Anuja Dave
- Department of Crop GeneticsJohn Innes CentreNorwich Research ParkNorwichNR4 7UHUK
| | - Luis Lopez‐Molina
- Department of Plant Biology and Institute for Genetics and Genomics in Geneva (iGE3)University of Geneva30, Quai Ernest‐Ansermet CH‐1211Geneva4Switzerland
| | - Steven Penfield
- Department of Crop GeneticsJohn Innes CentreNorwich Research ParkNorwichNR4 7UHUK
| |
Collapse
|
53
|
Hughes PW, Soppe WJJ, Albani MC. Seed traits are pleiotropically regulated by the flowering time gene PERPETUAL FLOWERING 1 (PEP1) in the perennial Arabis alpina. Mol Ecol 2019; 28:1183-1201. [PMID: 30712274 PMCID: PMC6850658 DOI: 10.1111/mec.15034] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Revised: 10/22/2018] [Accepted: 11/19/2018] [Indexed: 01/20/2023]
Abstract
The life cycles of plants are characterized by two major life history transitions-germination and the initiation of flowering-the timing of which are important determinants of fitness. Unlike annuals, which make the transition from the vegetative to reproductive phase only once, perennials iterate reproduction in successive years. The floral repressor PERPETUAL FLOWERING 1 (PEP1), an ortholog of FLOWERING LOCUS C, in the alpine perennial Arabis alpina ensures the continuation of vegetative growth after flowering and thereby restricts the duration of the flowering episode. We performed greenhouse and garden experiments to compare flowering phenology, fecundity and seed traits between A. alpina accessions that have a functional PEP1 allele and flower seasonally and pep1 mutants and accessions that carry lesions in PEP1 and flower perpetually. In the garden, perpetual genotypes flower asynchronously and show higher winter mortality than seasonal ones. PEP1 also pleiotropically regulates seed dormancy and longevity in a way that is functionally divergent from FLC. Seeds from perpetual genotypes have shallow dormancy and reduced longevity regardless of whether they after-ripened in plants grown in the greenhouse or in the experimental garden. These results suggest that perpetual genotypes have higher mortality during winter but compensate by showing higher seedling establishment. Differences in seed traits between seasonal and perpetual genotypes are also coupled with differences in hormone sensitivity and expression of genes involved in hormonal pathways. Our study highlights the existence of pleiotropic regulation of seed traits by hub developmental regulators such as PEP1, suggesting that seed and flowering traits in perennial plants might be optimized in a coordinated fashion.
Collapse
Affiliation(s)
- Patrick William Hughes
- Max Planck Institute for Plant Breeding ResearchCologneGermany
- Botanical InstituteUniversity of CologneCologneGermany
| | - Wim J. J. Soppe
- Max Planck Institute for Plant Breeding ResearchCologneGermany
- Institute of Molecular Physiology and Biotechnology of Plants (IMBIO)University of BonnBonnGermany
- Present address:
Rijk ZwaanDe LierThe Netherlands
| | - Maria C. Albani
- Max Planck Institute for Plant Breeding ResearchCologneGermany
- Botanical InstituteUniversity of CologneCologneGermany
- Center of Excellence in Plant Sciences (CEPLAS)DüsseldorfGermany
| |
Collapse
|
54
|
Albertos P, Wagner K, Poppenberger B. Cold stress signalling in female reproductive tissues. PLANT, CELL & ENVIRONMENT 2019; 42:846-853. [PMID: 30043473 DOI: 10.1111/pce.13408] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Revised: 06/29/2018] [Accepted: 07/10/2018] [Indexed: 05/20/2023]
Abstract
Cold stress is a significant threat for plant productivity and impacts on plant distribution and crop production, particularly so when it occurs during the growth phase. A developmental stage at risk is that of flowering, since a single stress event during sensitive stages, such as the full-bloom stage of fruit trees can be fatal for reproductive success. Although pollen development and fertilization are widely viewed as the most critical reproductive phases, the development and function of female reproductive tissues, which in Angiosperms are embedded in the gynoecium, are also affected by cold stress. Today however, we have essentially no understanding of the cold stress response pathways that act during floral organogenesis. In this review, we briefly summarize our current knowledge of cold stress signalling modules active in vegetative tissues that may provide a framework of general principles also transferable to female reproductive tissues. We then align these signalling cascades with those that govern gynoecium development to identify factors that may act in both processes and could thereby contribute to cold stress responses in female reproductive tissues.
Collapse
Affiliation(s)
- Pablo Albertos
- Biotechnology of Horticultural Crops, TUM School of Life Sciences Weihenstephan, Technical University of Munich, Freising, Germany
| | - Konstantin Wagner
- Biotechnology of Horticultural Crops, TUM School of Life Sciences Weihenstephan, Technical University of Munich, Freising, Germany
| | - Brigitte Poppenberger
- Biotechnology of Horticultural Crops, TUM School of Life Sciences Weihenstephan, Technical University of Munich, Freising, Germany
| |
Collapse
|
55
|
Pullen N, Zhang N, Dobon Alonso A, Penfield S. Growth rate regulation is associated with developmental modification of source efficiency. NATURE PLANTS 2019; 5:148-152. [PMID: 30718925 DOI: 10.1038/s41477-018-0357-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Accepted: 12/21/2018] [Indexed: 05/19/2023]
Abstract
Plants modulate their growth rate according to seasonal and environmental cues using a suite of growth repressors known to interact directly with cellular machinery controlling cell division and growth. Mutants lacking growth repressors show increased growth rates1,2, but the mechanism by which these plants ensure source availability for faster growth is unclear. Here, we undertake a comprehensive analysis of the fast-growth phenotype of a quintuple growth-repressor mutant, using a combination of theoretical and experimental approaches to understand the physiological basis of source-sink coordination. Our results show that, in addition to the control of tissue growth rates, growth repressors also affect tissue composition and leaf thickness, modulating the efficiency of production of new photosynthetic capacity. Modelling suggests that increases in growth efficiency underlie growth-rate differences between the wild type and spatula della growth-repressor mutant, with spatula della requiring less carbon to synthesize a comparable photosynthetic capability to the wild type, and fixing more carbon per unit mass. We conclude that through control of leaf development, growth repressors regulate both source availability and sink strength to achieve growth-rate variation without risking a carbon deficit.
Collapse
Affiliation(s)
- Nick Pullen
- Crop Genetics, John Innes Centre, Norwich, UK
| | | | | | | |
Collapse
|
56
|
Tognacca RS, Servi L, Hernando CE, Saura-Sanchez M, Yanovsky MJ, Petrillo E, Botto JF. Alternative Splicing Regulation During Light-Induced Germination of Arabidopsis thaliana Seeds. FRONTIERS IN PLANT SCIENCE 2019; 10:1076. [PMID: 31552074 PMCID: PMC6746916 DOI: 10.3389/fpls.2019.01076] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Accepted: 08/07/2019] [Indexed: 05/17/2023]
Abstract
Seed dormancy and germination are relevant processes for a successful seedling establishment in the field. Light is one of the most important environmental factors involved in the relief of dormancy to promote seed germination. In Arabidopsis thaliana seeds, phytochrome photoreceptors tightly regulate gene expression at different levels. The contribution of alternative splicing (AS) regulation in the photocontrol of seed germination is still unknown. The aim of this work is to study gene expression modulated by light during germination of A. thaliana seeds, with focus on AS changes. Hence, we evaluated transcriptome-wide changes in stratified seeds irradiated with a pulse of red (Rp) or far-red (FRp) by RNA sequencing (RNA-seq). Our results show that the Rp changes the expression of ∼20% of the transcriptome and modifies the AS pattern of 226 genes associated with mRNA processing, RNA splicing, and mRNA metabolic processes. We further confirmed these effects for some of the affected AS events. Interestingly, the reverse transcriptase-polymerase chain reaction (RT-PCR) analyses show that the Rp modulates the AS of splicing-related factors (At-SR30, At-RS31a, At-RS31, and At-U2AF65A), a light-signaling component (At-PIF6), and a dormancy-related gene (At-DRM1). Furthermore, while the phytochrome B (phyB) is responsible for the AS pattern changes of At-U2AF65A and At-PIF6, the regulation of the other AS events is independent of this photoreceptor. We conclude that (i) Rp triggers AS changes in some splicing factors, light-signaling components, and dormancy/germination regulators; (ii) phyB modulates only some of these AS events; and (iii) AS events are regulated by R and FR light, but this regulation is not directly associated with the intensity of germination response. These data will help in boosting research in the splicing field and our understanding about the role of this mechanism during the photocontrol of seed germination.
Collapse
Affiliation(s)
- Rocío Soledad Tognacca
- Consejo Nacional de Investigaciones Científicas y Técnicas, Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura (IFEVA), Facultad de Agronomía, Universidad de Buenos Aires, Buenos Aires, Argentina
- Facultad de Ciencias Exactas y Naturales, Departamento de Fisiología, Biología Molecular y Celular and CONICET-UBA, Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE), Universidad de Buenos Aires (UBA), Buenos Aires, Argentina
| | - Lucas Servi
- Facultad de Ciencias Exactas y Naturales, Departamento de Fisiología, Biología Molecular y Celular and CONICET-UBA, Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE), Universidad de Buenos Aires (UBA), Buenos Aires, Argentina
| | | | - Maite Saura-Sanchez
- Consejo Nacional de Investigaciones Científicas y Técnicas, Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura (IFEVA), Facultad de Agronomía, Universidad de Buenos Aires, Buenos Aires, Argentina
| | | | - Ezequiel Petrillo
- Facultad de Ciencias Exactas y Naturales, Departamento de Fisiología, Biología Molecular y Celular and CONICET-UBA, Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE), Universidad de Buenos Aires (UBA), Buenos Aires, Argentina
- *Correspondence: Ezequiel Petrillo, ; Javier Francisco Botto,
| | - Javier Francisco Botto
- Consejo Nacional de Investigaciones Científicas y Técnicas, Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura (IFEVA), Facultad de Agronomía, Universidad de Buenos Aires, Buenos Aires, Argentina
- *Correspondence: Ezequiel Petrillo, ; Javier Francisco Botto,
| |
Collapse
|
57
|
Wang M, Li W, Fang C, Xu F, Liu Y, Wang Z, Yang R, Zhang M, Liu S, Lu S, Lin T, Tang J, Wang Y, Wang H, Lin H, Zhu B, Chen M, Kong F, Liu B, Zeng D, Jackson SA, Chu C, Tian Z. Parallel selection on a dormancy gene during domestication of crops from multiple families. Nat Genet 2018; 50:1435-1441. [PMID: 30250128 DOI: 10.1038/s41588-018-0229-2] [Citation(s) in RCA: 127] [Impact Index Per Article: 21.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Accepted: 08/07/2018] [Indexed: 12/27/2022]
Abstract
Domesticated species often exhibit convergent phenotypic evolution, termed the domestication syndrome, of which loss of seed dormancy is a component. To date, dormancy genes that contribute to parallel domestication across different families have not been reported. Here, we cloned the classical stay-green G gene from soybean and found that it controls seed dormancy and showed evidence of selection during soybean domestication. Moreover, orthologs in rice and tomato also showed evidence of selection during domestication. Analysis of transgenic plants confirmed that orthologs of G had conserved functions in controlling seed dormancy in soybean, rice, and Arabidopsis. Functional investigation demonstrated that G affected seed dormancy through interactions with NCED3 and PSY and in turn modulated abscisic acid synthesis. Therefore, we identified a gene responsible for seed dormancy that has been subject to parallel selection in multiple crop families. This may help facilitate the domestication of new crops.
Collapse
Affiliation(s)
- Min Wang
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Wenzhen Li
- University of Chinese Academy of Sciences, Beijing, China
- State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - Chao Fang
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Fan Xu
- University of Chinese Academy of Sciences, Beijing, China
- State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - Yucheng Liu
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Zheng Wang
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - Rui Yang
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - Min Zhang
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - Shulin Liu
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Sijia Lu
- School of Life Sciences, Guangzhou University, Guangzhou, China
- Key Laboratory of Soybean Molecular Design Breeding, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin, China
| | - Tao Lin
- State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - Jiuyou Tang
- State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - Yiqin Wang
- State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - Hongru Wang
- State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - Hao Lin
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Baoge Zhu
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - Mingsheng Chen
- University of Chinese Academy of Sciences, Beijing, China
- State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - Fanjiang Kong
- School of Life Sciences, Guangzhou University, Guangzhou, China
- Key Laboratory of Soybean Molecular Design Breeding, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin, China
| | - Baohui Liu
- School of Life Sciences, Guangzhou University, Guangzhou, China
- Key Laboratory of Soybean Molecular Design Breeding, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin, China
| | - Dali Zeng
- State Key Laboratory of Rice Biology, China National Rice Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou, China
| | - Scott A Jackson
- Center for Applied Genetic Technologies, Department of Crop and Soil Sciences, University of Georgia, Athens, GA, USA.
| | - Chengcai Chu
- University of Chinese Academy of Sciences, Beijing, China.
- State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China.
| | - Zhixi Tian
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China.
- University of Chinese Academy of Sciences, Beijing, China.
| |
Collapse
|
58
|
Wu M, Upreti S, Yan A, Wakeel A, Wu J, Ge S, Liu Y, Liu B, Gan Y. SPATULA regulates floral transition and photomorphogenesis in a PHYTOCHROME B-dependent manner in Arabidopsis. Biochem Biophys Res Commun 2018; 503:2380-2385. [PMID: 29966653 DOI: 10.1016/j.bbrc.2018.06.165] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Accepted: 06/28/2018] [Indexed: 11/16/2022]
Abstract
Light is the most important exogenous stimulus regulating plant growth and various developmental processes. Phytochromes, especially PHYTOCHROME B (PHYB) mediates the various light-mediated processes in Arabidopsis. SPATULA (SPT) is an important transcription factor, which has been reported previously to participate in temperature-mediated transition from seed dormancy to germination. Here we investigate the function of SPT in the floral transition under long day conditions and photomorphogenesis in Arabidopsis. In this study, spt-2 shows significantly delayed flowering time. But mutation of SPT in the background of phyb-1 rescues the phenotype of spt-2. The flowering time of double mutant of spt-2/phyb-1 is similar with the wild type. These results indicate that SPT promotes the transition from vegetative stage to floral stage and it regulates this transition in a PHYB-dependent manner. With qRT-PCR analysis, it is found that SPT regulates flowering time via FLC, SVP, FT and SOC1. Furthermore, SPT also controls photomorphogenesis. spt-2 displays shortened hypocotyls and increased chlorophylls contents compared with the wild type. These phenotypes are also rescued in the double mutant of spt-2/phyb-1. These results indicate that SPT is also involved in photomorphogenic development in Arabidopsis and SPT regulates photomorphogenesis in a PHYB-dependent manner. Collectively, SPT is not only a temperature responder but it is also an important light regulator during plant growth and development.
Collapse
Affiliation(s)
- Minjie Wu
- Zhejiang Key Lab of Crop Germplasm, Department of Agronomy, College of Agriculture and Biotechnology, Zhejiang University, 866 Yuhangtang Road, Hangzhou, 310058, China
| | - Sakila Upreti
- Zhejiang Key Lab of Crop Germplasm, Department of Agronomy, College of Agriculture and Biotechnology, Zhejiang University, 866 Yuhangtang Road, Hangzhou, 310058, China
| | - An Yan
- Natural Sciences and Science Education, National Institute of Education, Nanyang Technological University, 1 Nanyang Walk, Singapore, 637616, Singapore
| | - Abdul Wakeel
- Zhejiang Key Lab of Crop Germplasm, Department of Agronomy, College of Agriculture and Biotechnology, Zhejiang University, 866 Yuhangtang Road, Hangzhou, 310058, China
| | - Junyu Wu
- Zhejiang Key Lab of Crop Germplasm, Department of Agronomy, College of Agriculture and Biotechnology, Zhejiang University, 866 Yuhangtang Road, Hangzhou, 310058, China
| | - Song Ge
- Zhejiang Key Lab of Crop Germplasm, Department of Agronomy, College of Agriculture and Biotechnology, Zhejiang University, 866 Yuhangtang Road, Hangzhou, 310058, China
| | - Yihua Liu
- Zhejiang Key Lab of Crop Germplasm, Department of Agronomy, College of Agriculture and Biotechnology, Zhejiang University, 866 Yuhangtang Road, Hangzhou, 310058, China
| | - Bohan Liu
- Zhejiang Key Lab of Crop Germplasm, Department of Agronomy, College of Agriculture and Biotechnology, Zhejiang University, 866 Yuhangtang Road, Hangzhou, 310058, China
| | - Yinbo Gan
- Zhejiang Key Lab of Crop Germplasm, Department of Agronomy, College of Agriculture and Biotechnology, Zhejiang University, 866 Yuhangtang Road, Hangzhou, 310058, China.
| |
Collapse
|
59
|
Chen M, Penfield S. Feedback regulation of COOLAIR expression controls seed dormancy and flowering time. Science 2018; 360:1014-1017. [PMID: 29853684 DOI: 10.1126/science.aar7361] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Accepted: 04/13/2018] [Indexed: 12/30/2022]
Abstract
Plants integrate seasonal signals, including temperature and day length, to optimize the timing of developmental transitions. Seasonal sensing requires the activity of two proteins, FLOWERING LOCUS C (FLC) and FLOWERING LOCUS T (FT), that control certain developmental transitions in plants. During reproductive development, the mother plant uses FLC and FT to modulate progeny seed dormancy in response to temperature. We found that for regulation of seed dormancy, FLC and FT function in opposite configuration to how those same genes control time to flowering. For seed dormancy, FT regulates seed dormancy through FLC gene expression and regulates chromatin state by activating antisense FLC transcription. Thus, in Arabidopsis the same genes controlled in opposite format regulate flowering time and seed dormancy in response to the temperature changes that characterize seasons.
Collapse
Affiliation(s)
- Min Chen
- Department of Crop Genetics, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Steven Penfield
- Department of Crop Genetics, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK.
| |
Collapse
|
60
|
MOTHER-OF-FT-AND-TFL1 represses seed germination under far-red light by modulating phytohormone responses in Arabidopsis thaliana. Proc Natl Acad Sci U S A 2018; 115:8442-8447. [PMID: 30061395 PMCID: PMC6099910 DOI: 10.1073/pnas.1806460115] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Seed germination in many plant species is triggered by sunlight, which is rich in the red (R) wavelength and repressed by under-the-canopy light rich in far red (FR). R:FR ratios are sensed by phytochromes to regulate levels of gibberellins (GAs) and abscisic acid (ABA), which induce and inhibit germination respectively. In this study we have discovered that, under FR light conditions, germination is repressed by MOTHER-OF-FT-AND-TFL1 (MFT) through the regulation of the ABA and GA signaling pathways. We also show that MFT gene expression is tightly regulated by light quality. Previous work has shown that under FR light conditions the transcription factor PHYOCHROME-INTERACTING-FACTOR1 (PIF1) accumulates and promotes expression of SOMNUS (SOM) that, in turn, leads to increased ABA and decreased GA levels. PIF1 also promotes expression of genes encoding ABA-INSENSITIVE5 (ABI5) and DELLA growth-repressor proteins, which act in the ABA and GA signaling pathways, respectively. Here we show that MFT gene expression is promoted by FR light through the PIF1/SOM/ABI5/DELLA pathway and is repressed by R light via the transcription factor SPATULA (SPT). Consistent with this, we also show that SPT gene expression is repressed under FR light in a PIF1-dependent manner. Furthermore, transcriptomic analyses presented in this study indicate that MFT exerts its function by promoting expression of known ABA-induced genes and repressing cell wall expansion-related genes.
Collapse
|
61
|
Lymperopoulos P, Msanne J, Rabara R. Phytochrome and Phytohormones: Working in Tandem for Plant Growth and Development. FRONTIERS IN PLANT SCIENCE 2018; 9:1037. [PMID: 30100912 PMCID: PMC6072860 DOI: 10.3389/fpls.2018.01037] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Accepted: 06/26/2018] [Indexed: 05/07/2023]
Abstract
Being sessile organisms, plants need to continually adapt and modulate their rate of growth and development in accordance with the changing environmental conditions, a phenomenon referred to as plasticity. Plasticity in plants is a highly complex process that involves a well-coordinated interaction between different signaling pathways, the spatiotemporal involvement of phytohormones and cues from the environment. Though research studies are being carried out over the years to understand how plants perceive the signals from changing environmental conditions and activate plasticity, such remain a mystery to be resolved. Among all environmental cues, the light seems to be the stand out factor influencing plant growth and development. During the course of evolution, plants have developed well-equipped signaling system that enables regulation of both quantitative and qualitative differences in the amount of perceived light. Light influences essential developmental switches in plants ranging from germination or transition to flowering, photomorphogenesis, as well as switches in response to shade avoidances and architectural changes occurring during phototropism. Abscisic acid (ABA) is controlling seed germination and is regulated by light. Furthermore, circadian clock adds another level of regulation to plant growth by integrating light signals with different hormonal pathways. MYB96 has been identified as a regulator of circadian gating of ABA-mediated responses in plants by binding to the TIMING OF CAB EXPRESSION 1(TOC1) promoter. This review will present a representative regulatory model, highlight the successes achieved in employing novel strategies to dissect the levels of interaction and provide perspective for future research on phytochrome-phytohormones relationships toward facilitating plant growth, development, and function under abiotic-biotic stresses.
Collapse
Affiliation(s)
| | - Joseph Msanne
- New Mexico Consortium, Los Alamos, NM, United States
| | - Roel Rabara
- New Mexico Consortium, Los Alamos, NM, United States
| |
Collapse
|
62
|
KELCH F-BOX protein positively influences Arabidopsis seed germination by targeting PHYTOCHROME-INTERACTING FACTOR1. Proc Natl Acad Sci U S A 2018; 115:E4120-E4129. [PMID: 29632208 PMCID: PMC5924874 DOI: 10.1073/pnas.1711919115] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The completion of seed germination is an irrevocable event for plants, determining, for most plants, the site of the remainder of their life cycle. One environmental cue important to the completion of seed germination is light, which, in Arabidopsis thaliana, can influence a host of transcription factors, including PHYTOCHROME-INTERACTING FACTOR1 (PIF1), a negative regulator of the completion of germination and seedling de-etiolation. The KELCH F-BOX protein COLD TEMPERATURE GERMINATING10 (CTG10) can recognize and bind to PIF1, negatively influencing PIF1 stability, stimulating the completion of germination, and promoting a de-etiolated seedling morphology. PIF1, in turn, can downregulate CTG10 expression, revealing a complex coregulation orchestrated by light presence and quality that dictates whether the seed completes germination. Seeds employ sensory systems that assess various environmental cues over time to maximize the successful transition from embryo to seedling. Here we show that the Arabidopsis F-BOX protein COLD TEMPERATURE-GERMINATING (CTG)-10, identified by activation tagging, is a positive regulator of this process. When overexpressed (OE), CTG10 hastens aspects of seed germination. CTG10 is expressed predominantly in the hypocotyl, and the protein is localized to the nucleus. CTG10 interacts with PHYTOCHROME-INTERACTING FACTOR 1 (PIF1) and helps regulate its abundance in planta. CTG10-OE accelerates the loss of PIF1 in light, increasing germination efficiency, while PIF1-OE lines fail to complete germination in darkness, which is reversed by concurrent CTG10-OE. Double-mutant (pif1 ctg10) lines demonstrated that PIF1 is epistatic to CTG10. Both CTG10 and PIF1 amounts decline during seed germination in the light but reaccumulate in the dark. PIF1 in turn down-regulates CTG10 transcription, suggesting a feedback loop of CTG10/PIF1 control. The genetic, physiological, and biochemical evidence, when taken together, leads us to propose that PIF1 and CTG10 coexist, and even accumulate, in the nucleus in darkness, but that, following illumination, CTG10 assists in reducing PIF1 amounts, thus promoting the completion of seed germination and subsequent seedling development.
Collapse
|
63
|
Płażek A, Dubert F, Kopeć P, Dziurka M, Kalandyk A, Pastuszak J, Wolko B. Seed Hydropriming and Smoke Water Significantly Improve Low-Temperature Germination of Lupinus angustifolius L. Int J Mol Sci 2018; 19:E992. [PMID: 29587459 PMCID: PMC5979301 DOI: 10.3390/ijms19040992] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Revised: 03/23/2018] [Accepted: 03/23/2018] [Indexed: 12/01/2022] Open
Abstract
Seed imbibition under cold temperature is dangerous when dry seeds have relatively low water content. The aim of this study was to investigate germination of 20 lines/cultivars of narrow-leaf lupine at 7 °C (cold) and 13 °C (control) under the influence of smoke water and following seed hydropriming for 3 h at 20 °C. The efficacy of individual treatments was examined with regard to seed protection during low-temperature germination. Based on seed germination, vigour at cold was evaluated four days after sowing by means of hypocotyl length, the studied lines/cultivars were divided into three groups with low, high and very high germination rates. Germination vigour correlated with cell membrane permeability, dehydrogenase activity and abscisic acid (ABA) content and was analysed in the seeds one day after sowing. Gibberellin content did not correlate with germination vigour. The seeds of weakly germinating lines/cultivars had the highest cell permeability and ABA content as well as the lowest amylolytic activity at both studied temperatures. Additionally, the vigour of weakly germinating seeds at 7 °C correlated with dehydrogenase activity. Three-hour hydropriming was the most effective for seed germination under cold due to reduced cell membrane permeability and ABA level. Stimulating effects of smoke water on germination under cold could be explained by enhanced dehydrogenase activity.
Collapse
Affiliation(s)
- Agnieszka Płażek
- Department of Plant Physiology, University of Agriculture, Podłużna 3, 30-239 Kraków, Poland.
| | - Franciszek Dubert
- Polish Academy of Sciences, Institute of Plant Physiology, Niezapominajek 21, 30-239 Kraków, Poland.
| | - Przemysław Kopeć
- Polish Academy of Sciences, Institute of Plant Physiology, Niezapominajek 21, 30-239 Kraków, Poland.
| | - Michał Dziurka
- Polish Academy of Sciences, Institute of Plant Physiology, Niezapominajek 21, 30-239 Kraków, Poland.
| | - Agnieszka Kalandyk
- Polish Academy of Sciences, Institute of Plant Physiology, Niezapominajek 21, 30-239 Kraków, Poland.
| | - Jakub Pastuszak
- Department of Plant Physiology, University of Agriculture, Podłużna 3, 30-239 Kraków, Poland.
| | - Bogdan Wolko
- Polish Academy of Sciences, Institute of Plant Genetics, Strzeszyńska 34, 60-479 Poznań, Poland.
| |
Collapse
|
64
|
Midhat U, Ting MKY, Teresinski HJ, Snedden WA. The calmodulin-like protein, CML39, is involved in regulating seed development, germination, and fruit development in Arabidopsis. PLANT MOLECULAR BIOLOGY 2018; 96:375-392. [PMID: 29372457 DOI: 10.1007/s11103-018-0703-3] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Accepted: 01/12/2018] [Indexed: 05/10/2023]
Abstract
We show that the calcium sensor, CML39, is important in various developmental processes from seeds to mature plants. This study bridges previous work on CML39 as a stress-induced gene and highlights the importance of calcium signalling in plant development. In addition to the evolutionarily-conserved Ca2+ sensor, calmodulin (CaM), plants possess a large family of CaM-related proteins (CMLs). Using a cml39 loss-of-function mutant, we investigated the roles of CML39 in Arabidopsis and discovered a range of phenotypes across developmental stages and in different tissues. In mature plants, loss of CML39 results in shorter siliques, reduced seed number per silique, and reduced number of ovules per pistil. We also observed changes in seed development, germination, and seed coat properties in cml39 mutants in comparison to wild-type plants. Using radicle emergence as a measure of germination, cml39 mutants showed more rapid germination than wild-type plants. In marked contrast to wild-type seeds, the germination of developing, immature cml39 seeds was not sensitive to cold-stratification. In addition, germination of cml39 seeds was less sensitive than wild-type to inhibition by ABA or by treatments that impaired gibberellic acid biosynthesis. Tetrazolium red staining indicated that the seed-coat permeability of cml39 seeds is greater than that of wild-type seeds. RNA sequencing analysis of cml39 seedlings suggests that changes in chromatin modification may underlie some of the phenotypes associated with cml39 mutants, consistent with previous reports that orthologs of CML39 participate in gene silencing. Aberrant ectopic expression of transcripts for seed storage proteins in 7-day old cml39 seedlings was observed, suggesting mis-regulation of early developmental programs. Collectively, our data support a model where CML39 serves as an important Ca2+ sensor during ovule and seed development, as well as during germination and seedling establishment.
Collapse
Affiliation(s)
- Ubaid Midhat
- Department of Biology, Queen's University, Kingston, ON, K7L3N6, Canada
| | - Michael K Y Ting
- Department of Biology, Queen's University, Kingston, ON, K7L3N6, Canada
| | | | - Wayne A Snedden
- Department of Biology, Queen's University, Kingston, ON, K7L3N6, Canada.
| |
Collapse
|
65
|
Vishal B, Kumar PP. Regulation of Seed Germination and Abiotic Stresses by Gibberellins and Abscisic Acid. FRONTIERS IN PLANT SCIENCE 2018; 9:838. [PMID: 29973944 PMCID: PMC6019495 DOI: 10.3389/fpls.2018.00838] [Citation(s) in RCA: 114] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Accepted: 05/30/2018] [Indexed: 05/19/2023]
Abstract
Overall growth and development of a plant is regulated by complex interactions among various hormones, which is critical at different developmental stages. Some of the key aspects of plant growth include seed development, germination and plant survival under unfavorable conditions. Two of the key phytohormones regulating the associated physiological processes are gibberellins (GA) and abscisic acid (ABA). GAs participate in numerous developmental processes, including, seed development and seed germination, seedling growth, root proliferation, determination of leaf size and shape, flower induction and development, pollination and fruit expansion. Despite the association with abiotic stresses, ABA is essential for normal plant growth and development. It plays a critical role in different abiotic stresses by regulating various downstream ABA-dependent stress responses. Plants maintain a balance between GA and ABA levels constantly throughout the developmental processes at different tissues and organs, including under unfavorable environmental or physiological conditions. Here, we will review the literature on how GA and ABA control different stages of plant development, with focus on seed germination and selected abiotic stresses. The possible crosstalk of ABA and GA in specific events of the above processes will also be discussed, with emphasis on downstream stress signaling components, kinases and transcription factors (TFs). The importance of several key ABA and GA signaling intermediates will be illustrated. The knowledge gained from such studies will also help to establish a solid foundation to develop future crop improvement strategies.
Collapse
|
66
|
Ravindran P, Verma V, Stamm P, Kumar PP. A Novel RGL2-DOF6 Complex Contributes to Primary Seed Dormancy in Arabidopsis thaliana by Regulating a GATA Transcription Factor. MOLECULAR PLANT 2017; 10:1307-1320. [PMID: 28917589 DOI: 10.1016/j.molp.2017.09.004] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Revised: 08/28/2017] [Accepted: 09/04/2017] [Indexed: 05/17/2023]
Abstract
The DELLA protein RGA-LIKE2 (RGL2) is a key transcriptional repressor of gibberellic acid (GA) signaling that regulates seed germination. We identified GATA12, a gene encoding a GATA-type zinc finger transcription factor, as one of the downstream targets of RGL2 in Arabidopsis thaliana. Our data show that freshly harvested (unstratified) seeds of GATA12 antisense suppression lines have reduced dormancy compared with the wild-type, while ectopic expression lines show enhanced seed dormancy. We show that GATA12 expression is negatively regulated by GA, and its transcript levels decline dramatically under dormancy-breaking conditions such as dry storage and cold stratification of seeds. GATA12 promoter has several GAMYB- and DOF-associated motifs that are known to be GA- and RGL2-responsive, respectively. Chromatin immunoprecipitation assay showed that a protein complex containing RGL2 can bind to GATA12 promoter and thereby regulate its expression. RGL2 lacks a DNA binding domain and requires a transcription factor to induce GATA12 expression. Our data show that this RGL2-containing protein complex includes DNA BINDING1 ZINC FINGER6 (DOF6), which is a known negative regulator of germination in freshly harvested seeds. We further show that this novel RGL2-DOF6 complex is required for activating GATA12 expression, thus revealing a molecular mechanism to enforce primary seed dormancy.
Collapse
Affiliation(s)
- Pratibha Ravindran
- Department of Biological Sciences, Faculty of Science, National University of Singapore, Singapore 117543, Singapore
| | - Vivek Verma
- Department of Biological Sciences, Faculty of Science, National University of Singapore, Singapore 117543, Singapore
| | - Petra Stamm
- Department of Biological Sciences, Faculty of Science, National University of Singapore, Singapore 117543, Singapore
| | - Prakash P Kumar
- Department of Biological Sciences, Faculty of Science, National University of Singapore, Singapore 117543, Singapore.
| |
Collapse
|
67
|
Narro-Diego L, López-González L, Jarillo JA, Piñeiro M. The PHD-containing protein EARLY BOLTING IN SHORT DAYS regulates seed dormancy in Arabidopsis. PLANT, CELL & ENVIRONMENT 2017; 40:2393-2405. [PMID: 28770581 DOI: 10.1111/pce.13046] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Revised: 07/26/2017] [Accepted: 07/27/2017] [Indexed: 05/20/2023]
Abstract
The Arabidopsis protein EARLY BOLTING IN SHORT DAYS (EBS), a plant-specific transcriptional regulator, is involved in the control of flowering time by repressing the floral integrator FT. The EBS protein binds the H3K4me3 histone mark and interacts with histone deacetylases to modulate gene expression. Here, we show that EBS also participates in the regulation of seed dormancy. ebs mutations cause a reduction in seed dormancy, and the concurrent loss of function of the EBS homologue SHORT LIFE (SHL) enhances this dormancy alteration. Transcriptomic analyses in ebs mutant seeds uncovered the misregulation of several regulators of seed dormancy including the MADS box gene AGAMOUS-LIKE67 (AGL67). AGL67 interacts genetically with EBS in seed dormancy regulation, indicating that both loci act in the same pathway. Interestingly, EBS functions independently of the master regulator gene of dormancy DELAY OF GERMINATION 1 (DOG1) and other genes encoding chromatin remodelling factors involved in the control of seed dormancy. Altogether, these data show that EBS is a central repressor of germination during seed dormancy and that SHL acts redundantly with EBS in the control of this developmental process. Our observations suggest that a tightly regulated crosstalk among histone modifications is necessary for a proper control of seed dormancy.
Collapse
Affiliation(s)
- Laura Narro-Diego
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM)-Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Campus Montegancedo UPM, Pozuelo de Alarcón, Madrid, 28223, Spain
| | - Leticia López-González
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM)-Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Campus Montegancedo UPM, Pozuelo de Alarcón, Madrid, 28223, Spain
| | - Jose A Jarillo
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM)-Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Campus Montegancedo UPM, Pozuelo de Alarcón, Madrid, 28223, Spain
| | - Manuel Piñeiro
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM)-Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Campus Montegancedo UPM, Pozuelo de Alarcón, Madrid, 28223, Spain
| |
Collapse
|
68
|
Chen J, Chopra R, Hayes C, Morris G, Marla S, Burke J, Xin Z, Burow G. Genome-Wide Association Study of Developing Leaves' Heat Tolerance during Vegetative Growth Stages in a Sorghum Association Panel. THE PLANT GENOME 2017; 10. [PMID: 28724078 DOI: 10.3835/plantgenome2016.09.0091] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Heat stress reduces grain yield and quality worldwide. Enhancing heat tolerance of crops at all developmental stages is one of the essential strategies required for sustaining agricultural production especially as frequency of temperature extremes escalates in response to climate change. Although heat tolerance mechanisms have been studied extensively in model plant species, little is known about the genetic control underlying heat stress responses of crop plants at the vegetative stage under field conditions. To dissect the genetic basis of heat tolerance in sorghum [ (L.) Moench], we performed a genome-wide association study (GWAS) for traits responsive to heat stress at the vegetative stage in an association panel. Natural variation in leaf firing (LF) and leaf blotching (LB) were evaluated separately for 3 yr in experimental fields at three locations where sporadic heat waves occurred throughout the sorghum growing season. We identified nine single-nucleotide polymorphisms (SNPs) that were significantly associated with LF and five SNPs that were associated with LB. Candidate genes near the SNPs were investigated and 14 were directly linked to biological pathways involved in plant stress responses including heat stress response. The findings of this study provide new knowledge on the genetic control of leaf traits responsive to heat stress in sorghum, which could aid in elucidating the genetic and molecular mechanisms of vegetative stage heat tolerance in crops. The results also provide candidate markers for molecular breeding of enhanced heat tolerance in cereal and bioenergy crops.
Collapse
|
69
|
Guo XJ, Wang JR. Global identification, structural analysis and expression characterization of bHLH transcription factors in wheat. BMC PLANT BIOLOGY 2017; 17:90. [PMID: 28558686 PMCID: PMC5450219 DOI: 10.1186/s12870-017-1038-y] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2016] [Accepted: 05/15/2017] [Indexed: 05/06/2023]
Abstract
BACKGROUND Basic helix-loop-helix (bHLH) transcription factors (TFs), which are widely distributed in eukaryotic organisms, play crucial roles in plant development. However, no comprehensive analysis of the bHLH family in wheat (Triticum aestivum L.) has been undertaken previously. RESULTS In this study, 225 bHLH TFs predicted from wheat using genomic and RNA sequencing data were subjected to identification, classification, phylogenetic reconstruction, conserved motif characterization, chromosomal distribution determination and expression pattern analysis. One basic region, two helix regions and one loop region were found to be conserved in wheat bHLH TFs. The bHLH proteins could be separated into four categories based on sequences in their basic regions. Neighbor-joining-based phylogenetic analysis of conserved bHLH domains from wheat, Arabidopsis and rice identified 26 subfamilies of bHLH TFs, of which 23 were found in wheat. A total of 82 wheat bHLH genes had orthologs in Arabidopsis (27 TFs), rice (28 TFs) and both of them (27 TFs). Seven tissue-specific bHLH TF clusters were identified according to their expression patterns in endosperm, aleurone, seedlings, heading-stage spikes, flag leaves, shoots and roots. Expression levels of six endosperm-specifically expressed TFs measured by qPCR and RNA-seq showed a good correlation. CONCLUSION The 225 bHLH transcription factors identified from wheat could be classed into 23 subfamilies, and those members from the same subfamily with similar sequence motifs generally have similar expression patterns.
Collapse
Affiliation(s)
- Xiao-Jiang Guo
- Triticeae Research Institute, Sichuan Agricultural University, Chengdu, 611130 China
| | - Ji-Rui Wang
- Triticeae Research Institute, Sichuan Agricultural University, Chengdu, 611130 China
| |
Collapse
|
70
|
Yan A, Chen Z. The pivotal role of abscisic acid signaling during transition from seed maturation to germination. PLANT CELL REPORTS 2017; 36:689-703. [PMID: 27882409 DOI: 10.1007/s00299-016-2082-z] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2016] [Accepted: 11/15/2016] [Indexed: 05/22/2023]
Abstract
Seed maturation and germination are two continuous developmental processes that link two distinct generations in spermatophytes; the precise genetic control of these two processes is, therefore, crucially important for the survival of the next generation. Pieces of experimental evidence accumulated so far indicate that a concerted action of endogenous signals and environmental cues is required to govern these processes. Plant hormone abscisic acid (ABA) has been suggested to play a predominant role in directing seed maturation and maintaining seed dormancy under unfavorable environmental conditions until antagonized by gibberellins (GA) and certain environmental cues to allow the commencement of seed germination when environmental conditions are favorable; therefore, the balance of ABA and GA is a major determinant of the timing of seed germination. Due to the advent of new technologies and system biology approaches, molecular studies are beginning to draw a picture of the sophisticated genetic network that drives seed maturation during the past decade, though the picture is still incomplete and many details are missing. In this review, we summarize recent advances in ABA signaling pathway in the regulation of seed maturation as well as the transition from seed maturation to germination, and highlight the importance of system biology approaches in the study of seed maturation.
Collapse
Affiliation(s)
- An Yan
- Natural Sciences and Science Education, National Institute of Education, Nanyang Technological University, 1 Nanyang Walk, Singapore, 637616, Singapore
| | - Zhong Chen
- Natural Sciences and Science Education, National Institute of Education, Nanyang Technological University, 1 Nanyang Walk, Singapore, 637616, Singapore.
| |
Collapse
|
71
|
Reyes-Olalde JI, Zúñiga-Mayo VM, Serwatowska J, Chavez Montes RA, Lozano-Sotomayor P, Herrera-Ubaldo H, Gonzalez-Aguilera KL, Ballester P, Ripoll JJ, Ezquer I, Paolo D, Heyl A, Colombo L, Yanofsky MF, Ferrandiz C, Marsch-Martínez N, de Folter S. The bHLH transcription factor SPATULA enables cytokinin signaling, and both activate auxin biosynthesis and transport genes at the medial domain of the gynoecium. PLoS Genet 2017; 13:e1006726. [PMID: 28388635 PMCID: PMC5400277 DOI: 10.1371/journal.pgen.1006726] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Revised: 04/21/2017] [Accepted: 03/30/2017] [Indexed: 11/18/2022] Open
Abstract
Fruits and seeds are the major food source on earth. Both derive from the gynoecium and, therefore, it is crucial to understand the mechanisms that guide the development of this organ of angiosperm species. In Arabidopsis, the gynoecium is composed of two congenitally fused carpels, where two domains: medial and lateral, can be distinguished. The medial domain includes the carpel margin meristem (CMM) that is key for the production of the internal tissues involved in fertilization, such as septum, ovules, and transmitting tract. Interestingly, the medial domain shows a high cytokinin signaling output, in contrast to the lateral domain, where it is hardly detected. While it is known that cytokinin provides meristematic properties, understanding on the mechanisms that underlie the cytokinin signaling pattern in the young gynoecium is lacking. Moreover, in other tissues, the cytokinin pathway is often connected to the auxin pathway, but we also lack knowledge about these connections in the young gynoecium. Our results reveal that cytokinin signaling, that can provide meristematic properties required for CMM activity and growth, is enabled by the transcription factor SPATULA (SPT) in the medial domain. Meanwhile, cytokinin signaling is confined to the medial domain by the cytokinin response repressor ARABIDOPSIS HISTIDINE PHOSPHOTRANSFERASE 6 (AHP6), and perhaps by ARR16 (a type-A ARR) as well, both present in the lateral domains (presumptive valves) of the developing gynoecia. Moreover, SPT and cytokinin, probably together, promote the expression of the auxin biosynthetic gene TRYPTOPHAN AMINOTRANSFERASE OF ARABIDOPSIS 1 (TAA1) and the gene encoding the auxin efflux transporter PIN-FORMED 3 (PIN3), likely creating auxin drainage important for gynoecium growth. This study provides novel insights in the spatiotemporal determination of the cytokinin signaling pattern and its connection to the auxin pathway in the young gynoecium.
Collapse
Affiliation(s)
- J. Irepan Reyes-Olalde
- Unidad de Genómica Avanzada (LANGEBIO), Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), Irapuato, Guanajuato, México
| | - Víctor M. Zúñiga-Mayo
- Unidad de Genómica Avanzada (LANGEBIO), Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), Irapuato, Guanajuato, México
| | - Joanna Serwatowska
- Unidad de Genómica Avanzada (LANGEBIO), Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), Irapuato, Guanajuato, México
| | - Ricardo A. Chavez Montes
- Unidad de Genómica Avanzada (LANGEBIO), Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), Irapuato, Guanajuato, México
| | - Paulina Lozano-Sotomayor
- Unidad de Genómica Avanzada (LANGEBIO), Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), Irapuato, Guanajuato, México
| | - Humberto Herrera-Ubaldo
- Unidad de Genómica Avanzada (LANGEBIO), Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), Irapuato, Guanajuato, México
| | - Karla L. Gonzalez-Aguilera
- Unidad de Genómica Avanzada (LANGEBIO), Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), Irapuato, Guanajuato, México
| | - Patricia Ballester
- Instituto de Biología Molecular y Celular de Plantas, CSIC-UPV Universidad Politécnica de Valencia, Valencia, Spain
| | - Juan José Ripoll
- Division of Biological Sciences, University of California San Diego, La Jolla, California, United States of America
| | - Ignacio Ezquer
- Dipartimento di Bioscienze, Università degli Studi di Milano, Milan, Italy
| | - Dario Paolo
- Dipartimento di Bioscienze, Università degli Studi di Milano, Milan, Italy
| | - Alexander Heyl
- Biology Department, Adelphi University, Garden City, New York, United States of America
| | - Lucia Colombo
- Dipartimento di Bioscienze, Università degli Studi di Milano, Milan, Italy
| | - Martin F. Yanofsky
- Division of Biological Sciences, University of California San Diego, La Jolla, California, United States of America
| | - Cristina Ferrandiz
- Instituto de Biología Molecular y Celular de Plantas, CSIC-UPV Universidad Politécnica de Valencia, Valencia, Spain
| | | | - Stefan de Folter
- Unidad de Genómica Avanzada (LANGEBIO), Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), Irapuato, Guanajuato, México
- * E-mail:
| |
Collapse
|
72
|
Yan Q, Xia X, Sun Z, Fang Y. Depletion of Arabidopsis SC35 and SC35-like serine/arginine-rich proteins affects the transcription and splicing of a subset of genes. PLoS Genet 2017; 13:e1006663. [PMID: 28273088 PMCID: PMC5362245 DOI: 10.1371/journal.pgen.1006663] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2016] [Revised: 03/22/2017] [Accepted: 02/28/2017] [Indexed: 12/23/2022] Open
Abstract
Serine/arginine-rich (SR) proteins are important splicing factors which play significant roles in spliceosome assembly and splicing regulation. However, little is known regarding their biological functions in plants. Here, we analyzed the phenotypes of mutants upon depleting different subfamilies of Arabidopsis SR proteins. We found that loss of the functions of SC35 and SC35-like (SCL) proteins cause pleiotropic changes in plant morphology and development, including serrated leaves, late flowering, shorter roots and abnormal silique phyllotaxy. Using RNA-seq, we found that SC35 and SCL proteins play roles in the pre-mRNA splicing. Motif analysis revealed that SC35 and SCL proteins preferentially bind to a specific RNA sequence containing the AGAAGA motif. In addition, the transcriptions of a subset of genes are affected by the deletion of SC35 and SCL proteins which interact with NRPB4, a specific subunit of RNA polymerase II. The splicing of FLOWERING LOCUS C (FLC) intron1 and transcription of FLC were significantly regulated by SC35 and SCL proteins to control Arabidopsis flowering. Therefore, our findings provide mechanistic insight into the functions of plant SC35 and SCL proteins in the regulation of splicing and transcription in a direct or indirect manner to maintain the proper expression of genes and development. SR proteins were identified to be important splicing factors. This work generated mutants of different subfamilies of the classic Arabidopsis SR proteins. Genetic analysis revealed that loss of the function of SC35/SCL proteins influences the plant development. This study revealed SC35/SCL proteins regulate alternative splicing, preferentially bind a specific RNA motif, interact with NRPB4, and affect the transcription of a subset of genes. This study further revealed that SC35/SCL proteins control flowering by regulating the splicing and transcription of FLC. These results shed light on the functions of SR proteins in plants.
Collapse
Affiliation(s)
- Qingqing Yan
- National key Laboratory of Plant Molecular Genetics, Chinese Academy of Sciences Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences; University of Chinese Academy of Sciences, Shanghai, China
| | - Xi Xia
- National key Laboratory of Plant Molecular Genetics, Chinese Academy of Sciences Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences; University of Chinese Academy of Sciences, Shanghai, China
| | - Zhenfei Sun
- National key Laboratory of Plant Molecular Genetics, Chinese Academy of Sciences Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences; University of Chinese Academy of Sciences, Shanghai, China
| | - Yuda Fang
- National key Laboratory of Plant Molecular Genetics, Chinese Academy of Sciences Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences; University of Chinese Academy of Sciences, Shanghai, China
- * E-mail:
| |
Collapse
|
73
|
Penfield S, MacGregor DR. Effects of environmental variation during seed production on seed dormancy and germination. JOURNAL OF EXPERIMENTAL BOTANY 2017; 68:819-825. [PMID: 27940467 DOI: 10.1093/jxb/erw436] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The environment during seed production has major impacts on the behaviour of progeny seeds. It can be shown that for annual plants temperature perception over the whole life history of the mother can affect the germination rate of progeny, and instances have been documented where these affects cross whole generations. Here we discuss the current state of knowledge of signal transduction pathways controlling environmental responses during seed production, focusing both on events that take place in the mother plant and those that occur directly as a result of environmental responses in the developing zygote. We show that seed production environment effects are complex, involving overlapping gene networks active independently in fruit, seed coat, and zygotic tissues that can be deconstructed using careful physiology alongside molecular and genetic experiments.
Collapse
Affiliation(s)
- Steven Penfield
- Department of Crop Genetics, John Innes Centre, Norwich Research Park, Norwick, NR4 7UH, UK
| | - Dana R MacGregor
- Department of Crop Genetics, John Innes Centre, Norwich Research Park, Norwick, NR4 7UH, UK
| |
Collapse
|
74
|
Hu J, Jin J, Qian Q, Huang K, Ding Y. Small RNA and degradome profiling reveals miRNA regulation in the seed germination of ancient eudicot Nelumbo nucifera. BMC Genomics 2016; 17:684. [PMID: 27565736 PMCID: PMC5002175 DOI: 10.1186/s12864-016-3032-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Accepted: 08/22/2016] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND MicroRNAs (miRNAs) play important roles in plant growth and development. MiRNAs and their targets have been widely studied in model plants, but limited knowledge is available concerning this small RNA population and their targets in sacred lotus (Nelumbo nucifera Gaertn.). RESULTS In this study, a total of 145 known miRNAs belonging to 47 families and 78 novel miRNAs were identified during seed germination using high-throughput small RNA sequencing. Furthermore, some miRNA families which have not yet been reported in monocot or eudicot species were detected in N. nucifera, indicating that these miRNAs was divergence from monocots and core eudicots during evolution. Using degradome sequencing, 2580 targets were detected for all the miRNAs. GO (Gene Ontology) and KEGG pathway analyses showed that many target genes enriched in "regulation of transcription" and involved in "carbohydrate", "amino acid and energy metabolism". Nine miRNAs and three corresponding targets of them were further validated by quantitative RT-PCR. CONCLUSIONS The results present here suggested that many miRNAs were involved in the regulation of seed germination of sacred lotus, providing a foundation for future studies of sacred lotus seed longevity. Comparative analysis of miRNAs from different plants also provided insight into the evolutionary gains and losses of miRNAs in plants.
Collapse
Affiliation(s)
- Jihong Hu
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, 430072 China
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, 650223 China
| | - Jing Jin
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, 430072 China
| | - Qian Qian
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, 430072 China
| | - Keke Huang
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, 430072 China
| | - Yi Ding
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, 430072 China
| |
Collapse
|
75
|
Gangl R, Tenhaken R. Raffinose Family Oligosaccharides Act As Galactose Stores in Seeds and Are Required for Rapid Germination of Arabidopsis in the Dark. FRONTIERS IN PLANT SCIENCE 2016; 7:1115. [PMID: 27507985 PMCID: PMC4960254 DOI: 10.3389/fpls.2016.01115] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Accepted: 07/13/2016] [Indexed: 05/25/2023]
Abstract
Raffinose synthase 5 (AtRS5, At5g40390) was characterized from Arabidopsis as a recombinant enzyme. It has a far higher affinity for the substrates galactinol and sucrose than any other raffinose synthase previously reported. In addition raffinose synthase 5 is also working as a galactosylhydrolase, degrading galactinol, and raffinose under certain conditions. Together with raffinose synthase 4, which is predominantly a stachyose synthase, both enzymes contribute to the raffinose family oligosaccharide (RFO) accumulation in seeds. A double knockout in raffinose synthase 4 and raffinose synthase 5 (ΔAtRS4,5) was generated, which is devoid of RFOs in seeds. Unstressed leaves of 4 week old ΔAtRS4,5 plants showed drastically 23.8-fold increased concentrations of galactinol. Unexpectedly, raffinose appeared again in drought stressed ΔAtRS4,5 plants, but not under other abiotic stress conditions. Drought stress leads to novel transcripts of raffinose synthase 6 suggesting that this isoform is a further stress inducible raffinose synthase in Arabidopsis. ΔAtRS4,5 seeds showed a 5 days delayed germination phenotype in darkness and an elevated expression of the transcription factor phytochrome interacting factor 1 (AtPIF1) target gene AtPIF6, being a repressor of germination. This prolonged dormancy is not seen during germination in the light. Exogenous galactose partially promotes germination of ΔAtRS4,5 seeds in the dark suggesting that RFOs act as a galactose store and repress AtPIF6 transcripts.
Collapse
Affiliation(s)
| | - Raimund Tenhaken
- Department of Cell Biology, Division of Plant Physiology, University of SalzburgSalzburg, Austria
| |
Collapse
|
76
|
Zhao W, Guan C, Feng J, Liang Y, Zhan N, Zuo J, Ren B. The Arabidopsis CROWDED NUCLEI genes regulate seed germination by modulating degradation of ABI5 protein. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2016; 58:669-78. [PMID: 26564029 DOI: 10.1111/jipb.12448] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Accepted: 11/10/2015] [Indexed: 05/18/2023]
Abstract
In Arabidopsis, the phytohormone abscisic acid (ABA) plays a vital role in inhibiting seed germination and in post-germination seedling establishment. In the ABA signaling pathway, ABI5, a basic Leu zipper transcription factor, has important functions in the regulation of seed germination. ABI5 protein localizes in nuclear bodies, along with AFP, COP1, and SIZ1, and was degraded through the 26S proteasome pathway. However, the mechanisms of ABI5 nuclear body formation and ABI5 protein degradation remain obscure. In this study, we found that the Arabidopsis CROWDED NUCLEI (CRWN) proteins, predicted nuclear matrix proteins essential for maintenance of nuclear morphology, also participate in ABA-controlled seed germination by regulating the degradation of ABI5 protein. During seed germination, the crwn mutants are hypersensitive to ABA and have higher levels of ABI5 protein compared to wild type. Genetic analysis suggested that CRWNs act upstream of ABI5. The observation that CRWN3 colocalizes with ABI5 in nuclear bodies indicates that CRWNs might participate in ABI5 protein degradation in nuclear bodies. Moreover, we revealed that the extreme C-terminal of CRWN3 protein is necessary for its function in the response to ABA in germination. Our results suggested important roles of CRWNs in ABI5 nuclear body organization and ABI5 protein degradation during seed germination.
Collapse
Affiliation(s)
- Wenming Zhao
- State Key Laboratory of Plant Genomics and National Plant Gene Research Center, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Chunmei Guan
- State Key Laboratory of Plant Genomics and National Plant Gene Research Center, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Jian Feng
- State Key Laboratory of Plant Genomics and National Plant Gene Research Center, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yan Liang
- State Key Laboratory of Plant Genomics and National Plant Gene Research Center, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Ni Zhan
- State Key Laboratory of Plant Genomics and National Plant Gene Research Center, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jianru Zuo
- State Key Laboratory of Plant Genomics and National Plant Gene Research Center, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Bo Ren
- State Key Laboratory of Plant Genomics and National Plant Gene Research Center, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| |
Collapse
|
77
|
Abstract
Hormones are chemical substances that can affect many cellular and developmental processes at low concentrations. Plant hormones co-ordinate growth and development at almost all stages of the plant's life cycle by integrating endogenous signals and environmental cues. Much debate in hormone biology revolves around specificity and redundancy of hormone signalling. Genetic and molecular studies have shown that these small molecules can affect a given process through a signalling pathway that is specific for each hormone. However, classical physiological and genetic studies have also demonstrated that the same biological process can be regulated by many hormones through independent pathways (co-regulation) or shared pathways (cross-talk or cross-regulation). Interactions between hormone pathways are spatiotemporally controlled and thus can vary depending on the stage of development or the organ being considered. In this chapter we discuss interactions between abscisic acid, gibberellic acid and ethylene in the regulation of seed germination as an example of hormone cross-talk. We also consider hormone interactions in response to environmental signals, in particular light and temperature. We focus our discussion on the model plant Arabidopsis thaliana.
Collapse
|
78
|
Bassel GW. To Grow or not to Grow? TRENDS IN PLANT SCIENCE 2016; 21:498-505. [PMID: 26934952 DOI: 10.1016/j.tplants.2016.02.001] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Revised: 01/25/2016] [Accepted: 02/04/2016] [Indexed: 05/22/2023]
Abstract
The seed to seedling transition in plants is initiated following the termination of seed dormancy. Here, I present a simplified developmental framework describing the events underlying this transition. I discuss putative mechanisms of signal integration and their relation to a global developmental fate switch in seeds within this framework. I delineate the events that occur before and after the flipping of this switch, marking an important distinction between these different developmental states. To end, I propose that the final fate switch resides within the embryo, and is informed by the endosperm in arabidopsis (Arabidopsis thaliana). This framework can serve as a template to focus future research in seed science.
Collapse
Affiliation(s)
- George W Bassel
- School of Biosciences, University of Birmingham, Birmingham, B15 2TT, UK.
| |
Collapse
|
79
|
The Cultivation of Arabidopsis for Experimental Research Using Commercially Available Peat-Based and Peat-Free Growing Media. PLoS One 2016; 11:e0153625. [PMID: 27088495 PMCID: PMC4835059 DOI: 10.1371/journal.pone.0153625] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Accepted: 04/02/2016] [Indexed: 11/28/2022] Open
Abstract
Experimental research involving Arabidopsis thaliana often involves the quantification of phenotypic traits during cultivation on compost or other growing media. Many commercially-available growing media contain peat, but peat extraction is not sustainable due to its very slow rate of formation. Moreover, peat extraction reduces peatland biodiversity and releases stored carbon and methane into the atmosphere. Here, we compared the experimental performance of Arabidopsis on peat-based and several types of commercially-available peat-free growing media (variously formed from coir, composted bark, wood-fibre, and domestic compost), to provide guidance for reducing peat use in plant sciences research with Arabidopsis. Arabidopsis biomass accumulation and seed yield were reduced by cultivation on several types of peat-free growing media. Arabidopsis performed extremely poorly on coir alone, presumably because this medium was completely nitrate-free. Some peat-free growing media were more susceptible to fungal contamination. We found that autoclaving of control (peat-based) growing media had no effect upon any physiological parameters that we examined, compared with non-autoclaved control growing media, under our experimental conditions. Overall, we conclude that Arabidopsis performs best when cultivated on peat-based growing media because seed yield was almost always reduced when peat-free media were used. This may be because standard laboratory protocols and growth conditions for Arabidopsis are optimized for peat-based media. However, during the vegetative growth phase several phenotypic traits were comparable between plants cultivated on peat-based and some peat-free media, suggesting that under certain circumstances peat-free media can be suitable for phenotypic analysis of Arabidopsis.
Collapse
|
80
|
Dave A, Vaistij FE, Gilday AD, Penfield SD, Graham IA. Regulation of Arabidopsis thaliana seed dormancy and germination by 12-oxo-phytodienoic acid. JOURNAL OF EXPERIMENTAL BOTANY 2016; 67:2277-84. [PMID: 26873978 PMCID: PMC4809285 DOI: 10.1093/jxb/erw028] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
We previously demonstrated that the oxylipin 12-oxo-phytodienoic acid (OPDA) acts along with abscisic acid to regulate seed germination in Arabidopsis thaliana, but the mechanistic details of this synergistic interaction remain to be elucidated. Here, we show that OPDA acts through the germination inhibition effects of abscisic acid, the abscisic acid-sensing ABI5 protein, and the gibberellin-sensing RGL2 DELLA protein. We further demonstrate that OPDA also acts through another dormancy-promoting factor, MOTHER-OF-FT-AND-TFL1 (MFT). Both abscisic acid and MFT positively feed back into the OPDA pathway by promoting its accumulation. These results confirm the central role of OPDA in regulating seed dormancy and germination in A. thaliana and underline the complexity of interactions between OPDA and other dormancy-promoting factors such as abscisic acid, RGL2, and MFT.
Collapse
Affiliation(s)
- Anuja Dave
- Centre for Novel Agricultural Products, Department of Biology, University of York, York YO10 5DD, United Kingdom
| | - Fabián E Vaistij
- Centre for Novel Agricultural Products, Department of Biology, University of York, York YO10 5DD, United Kingdom
| | - Alison D Gilday
- Centre for Novel Agricultural Products, Department of Biology, University of York, York YO10 5DD, United Kingdom
| | - Steven D Penfield
- Department of Crop Genetics, John Innes Centre, Norwich NR4 7UH, United Kingdom
| | - Ian A Graham
- Centre for Novel Agricultural Products, Department of Biology, University of York, York YO10 5DD, United Kingdom
| |
Collapse
|
81
|
Shen X, Li Y, Pan Y, Zhong S. Activation of HLS1 by Mechanical Stress via Ethylene-Stabilized EIN3 Is Crucial for Seedling Soil Emergence. FRONTIERS IN PLANT SCIENCE 2016; 7:1571. [PMID: 27822221 PMCID: PMC5075538 DOI: 10.3389/fpls.2016.01571] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Accepted: 10/05/2016] [Indexed: 05/05/2023]
Abstract
The seeds of terrestrial flowering plants often start their life cycle in subterranean darkness. To protect the fragile apical meristematic tissues and cotyledons from mechanical injuries during soil penetration, dicotyledonous seedlings form an elegant apical hook at the top of the hypocotyl. The apical hook has been considered as an adaption structure to the subterranean environment. However, the role of the apical hook in seedling emergence and the molecular mechanism of apical hook formation under real-life conditions remain highly speculative. Here, we find that HOOKLESS 1 (HLS1), a critical gene in apical hook formation in Arabidopsis thaliana, is required for seedling emergence from the soil. When grown under soil, hls1 mutant exhibits severe emergence defects. By contrast, HLS1 overexpression in the hls1 background fully restores emergence defects and displays better emergence capacity than that of WT. Our results indicate that HLS1 transcription is stimulated in response to the mechanical stress of soil cover, which is dependent on the function of the transcription factors ETHYLENE INSENSITIVE 3 (EIN3) and EIN3-LIKE 1 (EIL1). Soil-conferred mechanical stress activates the ethylene signaling pathway to stabilize EIN3 by repressing the activity of the F-box proteins EBF1 and EBF2. These combined results reveal a signaling pathway in which plant seedlings transduce the mechanical pressure of soil cover to correctly modulate apical hook formation during soil emergence.
Collapse
|
82
|
Liu Y, Müller K, El-Kassaby YA, Kermode AR. Changes in hormone flux and signaling in white spruce (Picea glauca) seeds during the transition from dormancy to germination in response to temperature cues. BMC PLANT BIOLOGY 2015; 15:292. [PMID: 26680643 PMCID: PMC4683703 DOI: 10.1186/s12870-015-0638-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2015] [Accepted: 10/05/2015] [Indexed: 05/21/2023]
Abstract
BACKGROUND Seeds use environmental cues such as temperature to coordinate the timing of their germination, allowing plants to synchronize their life history with the seasons. Winter chilling is of central importance to alleviate seed dormancy, but very little is known of how chilling responses are regulated in conifer seeds. White spruce (Picea glauca) is an important conifer species of boreal forests in the North American taiga. The recent sequencing and assembly of the white spruce genome allows for comparative gene expression studies toward elucidating the molecular mechanisms governing dormancy alleviation by moist chilling. Here we focused on hormone metabolite profiling and analyses of genes encoding components of hormone signal transduction pathways, to elucidate changes during dormancy alleviation and to help address how germination cues such as temperature and light trigger radicle emergence. RESULTS ABA, GA, and auxin underwent considerable changes as seeds underwent moist chilling and during subsequent germination; likewise, transcripts encoding hormone-signaling components (e.g. ABI3, ARF4 and Aux/IAA) were differentially regulated during these critical stages. During moist chilling, active IAA was maintained at constant levels, but IAA conjugates (IAA-Asp and IAA-Glu) were substantially accumulated. ABA concentrations decreased during germination of previously moist-chilled seeds, while the precursor of bioactive GA1 (GA53) accumulated. We contend that seed dormancy and germination may be partly mediated through the changing hormone concentrations and a modulation of interactions between central auxin-signaling pathway components (TIR1/AFB, Aux/IAA and ARF4). In response to germination cues, namely exposure to light and to increased temperature: the transfer of seeds from moist-chilling to 30 °C, significant changes in gene transcripts and protein expression occurred during the first six hours, substantiating a very swift reaction to germination-promoting conditions after seeds had received sufficient exposure to the chilling stimulus. CONCLUSIONS The dormancy to germination transition in white spruce seeds was correlated with changes in auxin conjugation, auxin signaling components, and potential interactions between auxin-ABA signaling cascades (e.g. the transcription factor ARF4 and ABI3). Auxin flux adds a new dimension to the ABA:GA balance mechanism that underlies both dormancy alleviation by chilling, and subsequent radicle emergence to complete germination by warm temperature and light stimuli.
Collapse
Affiliation(s)
- Yang Liu
- Department of Forest and Conservation Sciences, Faculty of Forestry, University of British Columbia, Vancouver, British Columbia, V6T 1Z4, Canada.
| | - Kerstin Müller
- Department of Biological Sciences, Simon Fraser University, Burnaby, British Columbia, V5A 1S6, Canada.
| | - Yousry A El-Kassaby
- Department of Forest and Conservation Sciences, Faculty of Forestry, University of British Columbia, Vancouver, British Columbia, V6T 1Z4, Canada.
| | - Allison R Kermode
- Department of Biological Sciences, Simon Fraser University, Burnaby, British Columbia, V5A 1S6, Canada.
| |
Collapse
|
83
|
Lorenzo CD, Sanchez-Lamas M, Antonietti MS, Cerdán PD. Emerging Hubs in Plant Light and Temperature Signaling. Photochem Photobiol 2015; 92:3-13. [DOI: 10.1111/php.12535] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2015] [Accepted: 09/02/2015] [Indexed: 12/19/2022]
Affiliation(s)
| | | | | | - Pablo D. Cerdán
- Fundación Instituto Leloir; IIBBA-CONICET; Buenos Aires Argentina
- Facultad de Ciencias Exactas y Naturales; Universidad de Buenos Aires; Buenos Aires Argentina
| |
Collapse
|
84
|
Boex-Fontvieille E, Rustgi S, Reinbothe S, Reinbothe C. A Kunitz-type protease inhibitor regulates programmed cell death during flower development in Arabidopsis thaliana. JOURNAL OF EXPERIMENTAL BOTANY 2015; 66:6119-35. [PMID: 26160583 DOI: 10.1093/jxb/erv327] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Flower development and fertilization are tightly controlled in Arabidopsis thaliana. In order to permit the fertilization of a maximum amount of ovules as well as proper embryo and seed development, a subtle balance between pollen tube growth inside the transmitting tract and pollen tube exit from the septum is needed. Both processes depend on a type of programmed cell death that is still poorly understood. Here, it is shown that a Kunitz protease inhibitor related to water-soluble chlorophyll proteins of Brassicaceae (AtWSCP, encoded by At1g72290) is involved in controlling cell death during flower development in A. thaliana. Genetic, biochemical, and cell biology approaches revealed that WSCP physically interacts with RD21 (RESPONSIVE TO DESICCATION) and that this interaction in turn inhibits the activity of RD21 as a pro-death protein. The regulatory circuit identified depends on the restricted expression of WSCP in the transmitting tract and the septum epidermis. In a respective Atwscp knock-out mutant, flowers exhibited precocious cell death in the transmitting tract and unnatural death of septum epidermis cells. As a consequence, apical-basal pollen tube growth, fertilization of ovules, as well as embryo development and seed formation were perturbed. Together, the data identify a unique mechanism of cell death regulation that fine-tunes pollen tube growth.
Collapse
Affiliation(s)
- Edouard Boex-Fontvieille
- Laboratoire de Génétique Moléculaire des Plantes and Biologie Environnementale et Systémique (BEeSy), Université Joseph Fourier, LBFA, BP53F, 38041 Grenoble cedex 9, France
| | - Sachin Rustgi
- Molecular Plant Sciences, Department of Crop and Soil Sciences, Washington State University, Pullman WA 99164-6420, USA
| | - Steffen Reinbothe
- Laboratoire de Génétique Moléculaire des Plantes and Biologie Environnementale et Systémique (BEeSy), Université Joseph Fourier, LBFA, BP53F, 38041 Grenoble cedex 9, France
| | | |
Collapse
|
85
|
Lazaro A, Mouriz A, Piñeiro M, Jarillo JA. Red Light-Mediated Degradation of CONSTANS by the E3 Ubiquitin Ligase HOS1 Regulates Photoperiodic Flowering in Arabidopsis. THE PLANT CELL 2015; 27:2437-54. [PMID: 26373454 PMCID: PMC4815090 DOI: 10.1105/tpc.15.00529] [Citation(s) in RCA: 72] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Revised: 08/12/2015] [Accepted: 08/22/2015] [Indexed: 05/18/2023]
Abstract
The regulation of CONSTANS (CO) gene expression is crucial to accurately measure changes in daylength, which influences flowering time in Arabidopsis thaliana. CO expression is under both transcriptional and posttranslational control mechanisms. We previously showed that the E3 ubiquitin ligase HIGH EXPRESSION OF OSMOTICALLY RESPONSIVE GENES1 (HOS1) physically interacts with CO in Arabidopsis. This interaction is required to precisely modulate the timing of CO accumulation and, consequently, to maintain low levels of FLOWERING LOCUS T expression during the first part of the day. The data presented here demonstrate that HOS1 is involved in the red light-mediated degradation of CO that takes place in the early stages of the daylight period. Our results show that phytochrome B (phyB) is able to regulate flowering time, acting in the phloem companion cells, as previously described for CO and HOS1. Moreover, we reveal that phyB physically interacts with HOS1 and CO, indicating that the three proteins may be present in a complex in planta that is required to coordinate a correct photoperiodic response in Arabidopsis.
Collapse
Affiliation(s)
- Ana Lazaro
- Centro de Biotecnología y Genómica de Plantas, INIA-UPM, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, 28223 Madrid, Spain
| | - Alfonso Mouriz
- Centro de Biotecnología y Genómica de Plantas, INIA-UPM, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, 28223 Madrid, Spain
| | - Manuel Piñeiro
- Centro de Biotecnología y Genómica de Plantas, INIA-UPM, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, 28223 Madrid, Spain
| | - José A Jarillo
- Centro de Biotecnología y Genómica de Plantas, INIA-UPM, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, 28223 Madrid, Spain
| |
Collapse
|
86
|
Lee N, Park J, Kim K, Choi G. The Transcriptional Coregulator LEUNIG_HOMOLOG Inhibits Light-Dependent Seed Germination in Arabidopsis. THE PLANT CELL 2015; 27:2301-13. [PMID: 26276832 PMCID: PMC4568510 DOI: 10.1105/tpc.15.00444] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Accepted: 07/27/2015] [Indexed: 05/11/2023]
Abstract
PHYTOCHROME-INTERACTING FACTOR1 (PIF1) is a basic helix-loop-helix transcription factor that inhibits light-dependent seed germination in Arabidopsis thaliana. However, it remains unclear whether PIF1 requires other factors to regulate its direct targets. Here, we demonstrate that LEUNIG_HOMOLOG (LUH), a Groucho family transcriptional corepressor, binds to PIF1 and coregulates its targets. Not only are the transcriptional profiles of the luh and pif1 mutants remarkably similar, more than 80% of the seeds of both genotypes germinate in the dark. We show by chromatin immunoprecipitation that LUH binds a subset of PIF1 targets in a partially PIF1-dependent manner. Unexpectedly, we found LUH binds and coregulates not only PIF1-activated targets but also PIF1-repressed targets. Together, our results indicate LUH functions with PIF1 as a transcriptional coregulator to inhibit seed germination.
Collapse
Affiliation(s)
- Nayoung Lee
- Department of Biological Sciences, KAIST, Daejeon 305-701, Korea
| | - Jeongmoo Park
- Department of Biological Sciences, KAIST, Daejeon 305-701, Korea
| | - Keunhwa Kim
- Department of Biological Sciences, KAIST, Daejeon 305-701, Korea
| | - Giltsu Choi
- Department of Biological Sciences, KAIST, Daejeon 305-701, Korea
| |
Collapse
|
87
|
Kondhare K, Farrell A, Kettlewell P, Hedden P, Monaghan J. Pre-maturity α-amylase in wheat: The role of abscisic acid and gibberellins. J Cereal Sci 2015. [DOI: 10.1016/j.jcs.2015.03.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
|
88
|
Wang H, Wang H. Phytochrome signaling: time to tighten up the loose ends. MOLECULAR PLANT 2015; 8:540-51. [PMID: 25670340 DOI: 10.1016/j.molp.2014.11.021] [Citation(s) in RCA: 78] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2014] [Revised: 11/12/2014] [Accepted: 11/14/2014] [Indexed: 05/18/2023]
Abstract
Phytochromes are red and far-red light photoreceptors that play fundamental roles in controlling many aspects of plant growth and development in response to light. The past two decades have witnessed the mechanistic elucidation of the action mode of phytochromes, including their regulation by external and endogenous factors and how they exert their function as transcriptional regulators. More importantly, recent advances have substantially deepened our understanding on the integration of the phytochrome-mediated signal into other cellular and developmental processes, such as elongation of hypocotyls, shoot branching, circadian clock, and flowering time, which often involves complex intercellular and interorgan signaling. Based on these advances, this review illustrates a blueprint of our current understanding of phytochrome signaling and its crosstalk with other signaling pathways, and also points out still open questions that need to be addressed in the future.
Collapse
Affiliation(s)
- Hai Wang
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Haiyang Wang
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
| |
Collapse
|
89
|
Han C, Yang P. Studies on the molecular mechanisms of seed germination. Proteomics 2015; 15:1671-9. [PMID: 25597791 DOI: 10.1002/pmic.201400375] [Citation(s) in RCA: 113] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2014] [Revised: 12/03/2014] [Accepted: 01/14/2015] [Indexed: 11/07/2022]
Abstract
Seed germination that begins with imbibition and ends with radicle emergence is the first step for plant growth. Successful germination is not only crucial for seedling establishment but also important for crop yield. After being dispersed from mother plant, seed undergoes continuous desiccation in ecosystem and selects proper environment to trigger germination. Owing to the contribution of transcriptomic, proteomic, and molecular biological studies, molecular aspect of seed germination is elucidated well in Arabidopsis. Recently, more and more proteomic and genetic studies concerning cereal seed germination were performed on rice (Oryza sativa) and barley (Hordeum vulgare), which possess completely different seed structure and domestication background with Arabidopsis. In this review, both the common features and the distinct mechanisms of seed germination are compared among different plant species including Arabidopsis, rice, and maize. These features include morphological changes, cell and its related structure recovery, metabolic activation, hormone behavior, and transcription and translation activation. This review will provide more comprehensive insights into the molecular mechanisms of seed germination.
Collapse
Affiliation(s)
- Chao Han
- Key Laboratory of Plant Germplasm Enhancement and Speciality Agriculture, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, P. R. China
| | - Pingfang Yang
- Key Laboratory of Plant Germplasm Enhancement and Speciality Agriculture, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, P. R. China
| |
Collapse
|
90
|
Santopolo S, Boccaccini A, Lorrai R, Ruta V, Capauto D, Minutello E, Serino G, Costantino P, Vittorioso P. DOF AFFECTING GERMINATION 2 is a positive regulator of light-mediated seed germination and is repressed by DOF AFFECTING GERMINATION 1. BMC PLANT BIOLOGY 2015; 15:72. [PMID: 25850831 PMCID: PMC4355143 DOI: 10.1186/s12870-015-0453-1] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2014] [Accepted: 02/12/2015] [Indexed: 05/18/2023]
Abstract
BACKGROUND The transcription factor DOF AFFECTING GERMINATION1 (DAG1) is a repressor of the light-mediated seed germination process. DAG1 acts downstream PHYTOCHROME INTERACTING FACTOR3-LIKE 5 (PIL5), the master repressor, and negatively regulates gibberellin biosynthesis by directly repressing the biosynthetic gene AtGA3ox1. The Dof protein DOF AFFECTING GERMINATION (DAG2) shares a high degree of aminoacidic identity with DAG1. While DAG1 inactivation considerably increases the germination capability of seeds, the dag2 mutant has seeds with a germination potential substantially lower than the wild-type, indicating that these factors may play opposite roles in seed germination. RESULTS We show here that DAG2 expression is positively regulated by environmental factors triggering germination, whereas its expression is repressed by PIL5 and DAG1; by Chromatin Immuno Precipitation (ChIP) analysis we prove that DAG1 directly regulates DAG2. In addition, we show that Red light significantly reduces germination of dag2 mutant seeds. CONCLUSIONS In agreement with the seed germination phenotype of the dag2 mutant previously published, the present data prove that DAG2 is a positive regulator of the light-mediated seed germination process, and particularly reveal that this protein plays its main role downstream of PIL5 and DAG1 in the phytochrome B (phyB)-mediated pathway.
Collapse
Affiliation(s)
- Silvia Santopolo
- />Dipartimento di Biologia e Biotecnologie “C. Darwin”, Sapienza Università di Roma, Piazzale Aldo Moro 5, 00185 Rome, Italy
| | - Alessandra Boccaccini
- />Dipartimento di Biologia e Biotecnologie “C. Darwin”, Sapienza Università di Roma, Piazzale Aldo Moro 5, 00185 Rome, Italy
- />Istituto Pasteur Fondazione Cenci Bolognetti, Dipartimento di Biologia e Biotecnologie “C. Darwin”, Sapienza Università di Roma, Piazzale Aldo Moro 5, 00185 Rome, Italy
| | - Riccardo Lorrai
- />Dipartimento di Biologia e Biotecnologie “C. Darwin”, Sapienza Università di Roma, Piazzale Aldo Moro 5, 00185 Rome, Italy
- />Istituto Pasteur Fondazione Cenci Bolognetti, Dipartimento di Biologia e Biotecnologie “C. Darwin”, Sapienza Università di Roma, Piazzale Aldo Moro 5, 00185 Rome, Italy
| | - Veronica Ruta
- />Dipartimento di Biologia e Biotecnologie “C. Darwin”, Sapienza Università di Roma, Piazzale Aldo Moro 5, 00185 Rome, Italy
| | - Davide Capauto
- />Dipartimento di Biologia e Biotecnologie “C. Darwin”, Sapienza Università di Roma, Piazzale Aldo Moro 5, 00185 Rome, Italy
| | - Emanuele Minutello
- />Dipartimento di Biologia e Biotecnologie “C. Darwin”, Sapienza Università di Roma, Piazzale Aldo Moro 5, 00185 Rome, Italy
| | - Giovanna Serino
- />Dipartimento di Biologia e Biotecnologie “C. Darwin”, Sapienza Università di Roma, Piazzale Aldo Moro 5, 00185 Rome, Italy
| | - Paolo Costantino
- />Dipartimento di Biologia e Biotecnologie “C. Darwin”, Sapienza Università di Roma, Piazzale Aldo Moro 5, 00185 Rome, Italy
| | - Paola Vittorioso
- />Dipartimento di Biologia e Biotecnologie “C. Darwin”, Sapienza Università di Roma, Piazzale Aldo Moro 5, 00185 Rome, Italy
- />Istituto Pasteur Fondazione Cenci Bolognetti, Dipartimento di Biologia e Biotecnologie “C. Darwin”, Sapienza Università di Roma, Piazzale Aldo Moro 5, 00185 Rome, Italy
| |
Collapse
|
91
|
Dogra V, Bagler G, Sreenivasulu Y. Re-analysis of protein data reveals the germination pathway and up accumulation mechanism of cell wall hydrolases during the radicle protrusion step of seed germination in Podophyllum hexandrum- a high altitude plant. FRONTIERS IN PLANT SCIENCE 2015; 6:874. [PMID: 26579141 PMCID: PMC4620410 DOI: 10.3389/fpls.2015.00874] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2015] [Accepted: 10/02/2015] [Indexed: 05/06/2023]
Abstract
Podophyllum hexandrum Royle is an important high-altitude plant of Himalayas with immense medicinal value. Earlier, it was reported that the cell wall hydrolases were up accumulated during radicle protrusion step of Podophyllum seed germination. In the present study, Podophyllum seed Germination protein interaction Network (PGN) was constructed by using the differentially accumulated protein (DAP) data set of Podophyllum during the radicle protrusion step of seed germination, with reference to Arabidopsis protein-protein interaction network (AtPIN). The developed PGN is comprised of a giant cluster with 1028 proteins having 10,519 interactions and a few small clusters with relevant gene ontological signatures. In this analysis, a germination pathway related cluster which is also central to the topology and information dynamics of PGN was obtained with a set of 60 key proteins. Among these, eight proteins which are known to be involved in signaling, metabolism, protein modification, cell wall modification, and cell cycle regulation processes were found commonly highlighted in both the proteomic and interactome analysis. The systems-level analysis of PGN identified the key proteins involved in radicle protrusion step of seed germination in Podophyllum.
Collapse
Affiliation(s)
- Vivek Dogra
- Biotechnology Division, Council of Scientific and Industrial Research-Institute of Himalayan Bioresource TechnologyPalampur, India
| | - Ganesh Bagler
- Centre for Biologically Inspired System Science, Indian Institute of Technology JodhpurJodhpur, India
- Ganesh Bagler
| | - Yelam Sreenivasulu
- Biotechnology Division, Council of Scientific and Industrial Research-Institute of Himalayan Bioresource TechnologyPalampur, India
- *Correspondence: Yelam Sreenivasulu ;
| |
Collapse
|
92
|
Maternal temperature history activates Flowering Locus T in fruits to control progeny dormancy according to time of year. Proc Natl Acad Sci U S A 2014; 111:18787-92. [PMID: 25516986 DOI: 10.1073/pnas.1412274111] [Citation(s) in RCA: 104] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Seasonal behavior is important for fitness in temperate environments but it is unclear how progeny gain their initial seasonal entrainment. Plants use temperature signals to measure time of year, and changes to life histories are therefore an important consequence of climate change. Here we show that in Arabidopsis the current and prior temperature experience of the mother plant is used to control germination of progeny seeds, via the activation of the florigen Flowering Locus T (FT) in fruit tissues. We demonstrate that maternal past and current temperature experience are transduced to the FT locus in silique phloem. In turn, FT controls seed dormancy through inhibition of proanthocyanidin synthesis in fruits, resulting in altered seed coat tannin content. Our data reveal that maternal temperature history is integrated through FT in the fruit to generate a metabolic signal that entrains the behavior of progeny seeds according to time of year.
Collapse
|
93
|
Boccaccini A, Santopolo S, Capauto D, Lorrai R, Minutello E, Belcram K, Palauqui JC, Costantino P, Vittorioso P. Independent and interactive effects of DOF affecting germination 1 (DAG1) and the Della proteins GA insensitive (GAI) and Repressor of ga1-3 (RGA) in embryo development and seed germination. BMC PLANT BIOLOGY 2014; 14:200. [PMID: 25064446 PMCID: PMC4222566 DOI: 10.1186/s12870-014-0200-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2014] [Accepted: 07/16/2014] [Indexed: 05/22/2023]
Abstract
BACKGROUND The transcription factor DOF AFFECTING GERMINATION1 (DAG1) is a repressor of seed germination acting downstream of the master repressor PHYTOCROME INTERACTING FACTOR3-LIKE 5 (PIL5). Among others, PIL5 induces the expression of the genes encoding the two DELLA proteins GA INSENSITIVE 1 (GAI) and REPRESSOR OF ga1-3 (RGA). RESULTS Based on the properties of gai-t6 and rga28 mutant seeds, we show here that the absence of RGA severely increases dormancy, while lack of GAI only partially compensates RGA inactivation. In addition, the germination properties of the dag1rga28 double mutant are different from those of the dag1 and rga28 single mutants, suggesting that RGA and DAG1 act in independent branches of the PIL5-controlled germination pathway. Surprisingly, the dag1gai-t6 double mutant proved embryo-lethal, suggesting an unexpected involvement of (a possible complex between) DAG1 and GAI in embryo development. CONCLUSIONS Rather than overlapping functions as previously suggested, we show that RGA and GAI play distinct roles in seed germination, and that GAI interacts with DAG1 in embryo development.
Collapse
Affiliation(s)
- Alessandra Boccaccini
- Istituto Pasteur Fondazione Cenci Bolognetti, Dipartimento di Biologia e Biotecnologie “C. Darwin”, Sapienza Università di Roma, Piazzale Aldo Moro 5, Rome, 00185, Italy
| | - Silvia Santopolo
- Istituto Pasteur Fondazione Cenci Bolognetti, Dipartimento di Biologia e Biotecnologie “C. Darwin”, Sapienza Università di Roma, Piazzale Aldo Moro 5, Rome, 00185, Italy
| | - Davide Capauto
- Istituto Pasteur Fondazione Cenci Bolognetti, Dipartimento di Biologia e Biotecnologie “C. Darwin”, Sapienza Università di Roma, Piazzale Aldo Moro 5, Rome, 00185, Italy
| | - Riccardo Lorrai
- Istituto Pasteur Fondazione Cenci Bolognetti, Dipartimento di Biologia e Biotecnologie “C. Darwin”, Sapienza Università di Roma, Piazzale Aldo Moro 5, Rome, 00185, Italy
| | - Emanuele Minutello
- Istituto Pasteur Fondazione Cenci Bolognetti, Dipartimento di Biologia e Biotecnologie “C. Darwin”, Sapienza Università di Roma, Piazzale Aldo Moro 5, Rome, 00185, Italy
| | - Katia Belcram
- Institut Jean-Pierre Bourgin, UMR1318 INRA-AgroParisTech, Bâtiment 2, INRA, Centre de Versailles-Grignon, Route de St-Cyr (RD10), Versailles Cedex, 78026, France
| | - Jean-Cristophe Palauqui
- Institut Jean-Pierre Bourgin, UMR1318 INRA-AgroParisTech, Bâtiment 2, INRA, Centre de Versailles-Grignon, Route de St-Cyr (RD10), Versailles Cedex, 78026, France
| | - Paolo Costantino
- Istituto Pasteur Fondazione Cenci Bolognetti, Dipartimento di Biologia e Biotecnologie “C. Darwin”, Sapienza Università di Roma, Piazzale Aldo Moro 5, Rome, 00185, Italy
| | - Paola Vittorioso
- Istituto Pasteur Fondazione Cenci Bolognetti, Dipartimento di Biologia e Biotecnologie “C. Darwin”, Sapienza Università di Roma, Piazzale Aldo Moro 5, Rome, 00185, Italy
- Dipartimento di Biologia e Biotecnologie “C. Darwin”, Sapienza Università di Roma, Piazzale Aldo Moro 5, Rome, 00185, Italy
| |
Collapse
|
94
|
Rombolá-Caldentey B, Rueda-Romero P, Iglesias-Fernández R, Carbonero P, Oñate-Sánchez L. Arabidopsis DELLA and two HD-ZIP transcription factors regulate GA signaling in the epidermis through the L1 box cis-element. THE PLANT CELL 2014; 26:2905-19. [PMID: 24989044 PMCID: PMC4145122 DOI: 10.1105/tpc.114.127647] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2014] [Revised: 05/13/2014] [Accepted: 06/13/2014] [Indexed: 05/21/2023]
Abstract
Gibberellins (GAs) are plant hormones that affect plant growth and regulate gene expression differentially across tissues. To study the molecular mechanisms underlying GA signaling in Arabidopsis thaliana, we focused on a GDSL lipase gene (LIP1) induced by GA and repressed by DELLA proteins. LIP1 contains an L1 box promoter sequence, conserved in the promoters of epidermis-specific genes, that is bound by ATML1, an HD-ZIP transcription factor required for epidermis specification. In this study, we demonstrate that LIP1 is specifically expressed in the epidermis and that its L1 box sequence mediates GA-induced transcription. We show that this sequence is overrepresented in the upstream regulatory regions of GA-induced and DELLA-repressed transcriptomes and that blocking GA signaling in the epidermis represses the expression of L1 box-containing genes and negatively affects seed germination. We show that DELLA proteins interact directly with ATML1 and its paralogue PDF2 and that silencing of both HD-ZIP transcription factors inhibits epidermal gene expression and delays germination. Our results indicate that, upon seed imbibition, increased GA levels reduce DELLA protein abundance and release ATML1/PDF2 to activate L1 box gene expression, thus enhancing germination potential.
Collapse
Affiliation(s)
- Belén Rombolá-Caldentey
- Centro de Biotecnología y Genómica de Plantas, UPM-INIA, and E.T.S.I. Agrónomos, Universidad Politécnica de Madrid, Campus de Montegancedo, Pozuelo de Alarcón, 28223 Madrid, Spain
| | - Paloma Rueda-Romero
- Centro de Biotecnología y Genómica de Plantas, UPM-INIA, and E.T.S.I. Agrónomos, Universidad Politécnica de Madrid, Campus de Montegancedo, Pozuelo de Alarcón, 28223 Madrid, Spain
| | - Raquel Iglesias-Fernández
- Centro de Biotecnología y Genómica de Plantas, UPM-INIA, and E.T.S.I. Agrónomos, Universidad Politécnica de Madrid, Campus de Montegancedo, Pozuelo de Alarcón, 28223 Madrid, Spain
| | - Pilar Carbonero
- Centro de Biotecnología y Genómica de Plantas, UPM-INIA, and E.T.S.I. Agrónomos, Universidad Politécnica de Madrid, Campus de Montegancedo, Pozuelo de Alarcón, 28223 Madrid, Spain
| | - Luis Oñate-Sánchez
- Centro de Biotecnología y Genómica de Plantas, UPM-INIA, and E.T.S.I. Agrónomos, Universidad Politécnica de Madrid, Campus de Montegancedo, Pozuelo de Alarcón, 28223 Madrid, Spain
| |
Collapse
|
95
|
Lee N, Kang H, Lee D, Choi G. A histone methyltransferase inhibits seed germination by increasing PIF1 mRNA expression in imbibed seeds. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2014; 78:282-93. [PMID: 24635727 DOI: 10.1111/tpj.12467] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2013] [Revised: 01/28/2014] [Accepted: 01/31/2014] [Indexed: 05/25/2023]
Abstract
Phytochrome-interacting factor 1 (PIF1) inhibits light-dependent seed germination. The specific function of PIF1 in seed germination is partly due to its high level of expression in imbibed seeds, but the associated regulatory factors have not been identified. Here we show that mutation of the early flowering in short days (EFS) gene, encoding an H3K4 and H3K36 methyltransferase, decreases the level of H3K36me2 and H3K36me3 but not H3K4me3 at the PIF1 locus, reduces the targeting of RNA polymerase II to the PIF1 locus, and reduces mRNA expression of PIF1 in imbibed seeds. Consistently, the efs mutant geminated even under the phyBoff condition, and had an expression profile of PIF1 target genes similar to that of the pif1 mutant. Introduction of an EFS transgene into the efs mutant restored the level of H3K36me2 and H3K36me3 at the PIF1 locus, the high-level expression of PIF1 mRNA, the expression pattern of PIF1 target genes, and the light-dependent germination of these seeds. Introduction of a PIF1 transgene into the efs mutant also restored the expression pattern of PIF1 target genes and light-dependent germination in imbibed seeds, but did not restore the flowering phenotype. Taken together, our results indicate that EFS is necessary for high-level expression of PIF1 mRNA in imbibed seeds.
Collapse
Affiliation(s)
- Nayoung Lee
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon, 305-701, Korea
| | | | | | | |
Collapse
|
96
|
Garzón MJ, Jensen O, Schweigmann N. Resistance to freezing temperatures in Aedes (Ochlerotatus) albifasciatus (Macquart) eggs (Diptera: Culicidae) from two different climatic regions of Argentina. JOURNAL OF VECTOR ECOLOGY : JOURNAL OF THE SOCIETY FOR VECTOR ECOLOGY 2013; 38:339-344. [PMID: 24581364 DOI: 10.1111/j.1948-7134.2013.12049.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2013] [Accepted: 06/12/2013] [Indexed: 06/03/2023]
Abstract
Aedes (Ochlerotatus) albifasciatus (Macquart) has the capacity to proliferate in different kinds of climates within its distribution range in South America. With the aim of studying local thermal adaptations of eggs, we exposed egg stocks from two climatically different localities: temperate humid pampa (Buenos Aires) and cold arid Patagonian (Sarmiento), to freezing conditions and then evaluated the effect on some features at this level. First, we thermally described the substrate where this species lays its eggs in the arid region. A typical thermal condition during winter was 10 h at -12° C. Second, we evaluated the effect of freezing on primary hatching (vs total hatching) and embryo survival. We also compared the proportion of embryonated eggs from both populations. The proportions of embryonated eggs were not different between localities, with averages of 78% and 83% in Sarmiento and Buenos Aires, respectively. Survival was equally successful after freezing in the two localities with an average range between 94-99%. Whether or not the eggs from Buenos Aires and Sarmiento were under freezing conditions, hatching was more than 98% after the first flooding. The results suggest that eggs of Ae. albifasciatus from Sarmiento and Buenos Aires have the same ability to survive at extreme temperatures (<0° C), showing a regional thermal adaptation rather than a local one.
Collapse
Affiliation(s)
- M J Garzón
- Grupo de Estudio de Mosquitos, Departamento de Ecología, Genética y Evolución, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires. Ciudad Autónoma de Buenos Aires, Argentina; CONICET, Departamento de Investigación en Salud, Secretaria de Salud, Chubut, Argentina.
| | | | | |
Collapse
|
97
|
Peng HH, Shan W, Kuang JF, Lu WJ, Chen JY. Molecular characterization of cold-responsive basic helix-loop-helix transcription factors MabHLHs that interact with MaICE1 in banana fruit. PLANTA 2013; 238:937-53. [PMID: 23955147 DOI: 10.1007/s00425-013-1944-7] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2013] [Accepted: 07/30/2013] [Indexed: 05/18/2023]
Abstract
Basic helix-loop-helix (bHLH) transcription factors (TFs) are ubiquitously involved in the response of higher plants to various abiotic stresses. However, little is known about bHLH TFs involved in the cold stress response in economically important fruits. Here, five novel full-length bHLH genes, designated as MabHLH1-MabHLH5, were isolated and characterized from banana fruit. Gene expression profiles revealed that MabHLH1/2/4 were induced by cold stress and methyl jasmonate (MeJA) treatment. Transient assays in tobacco BY2 protoplasts showed that MabHLH1/2/4 promoters were activated by cold stress and MeJA treatments. Moreover, protein-protein interaction analysis demonstrated that MabHLH1/2/4 not only physically interacted with each other to form hetero-dimers in the nucleus, but also interacted with an important upstream component of cold signaling MaICE1, with different interaction domains at their N-terminus. These results indicate that banana fruit cold-responsive MabHLHs may form a big protein complex in the nucleus with MaICE1. Taken together, our findings advance our understanding of the possible involvement of bHLH TFs in the regulatory network of ICE-CBF cold signaling pathway.
Collapse
Affiliation(s)
- Huan-Huan Peng
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources/Guangdong Key Laboratory for Postharvest Science, College of Horticultural Science, South China Agricultural University, Guangzhou, 510642, People's Republic of China
| | | | | | | | | |
Collapse
|
98
|
Donohue K. WHY ONTOGENY MATTERS DURING ADAPTATION: DEVELOPMENTAL NICHE CONSTRUCTION AND PLEIOTORPY ACROSS THE LIFE CYCLE INARABIDOPSIS THALIANA. Evolution 2013; 68:32-47. [DOI: 10.1111/evo.12284] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2013] [Accepted: 09/25/2013] [Indexed: 12/14/2022]
Affiliation(s)
- Kathleen Donohue
- Department of Biology; Duke University; Box 90338 Durham NC 27708
| |
Collapse
|
99
|
Shi H, Zhong S, Mo X, Liu N, Nezames CD, Deng XW. HFR1 sequesters PIF1 to govern the transcriptional network underlying light-initiated seed germination in Arabidopsis. THE PLANT CELL 2013; 25:3770-84. [PMID: 24179122 PMCID: PMC3877798 DOI: 10.1105/tpc.113.117424] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2013] [Revised: 09/30/2013] [Accepted: 10/14/2013] [Indexed: 05/19/2023]
Abstract
Seed germination is the first step for seed plants to initiate a new life cycle. Light plays a predominant role in promoting seed germination, where the initial phase is mediated by photoreceptor phytochrome B (phyB). Previous studies showed that phytochrome-interacting factor1 (PIF1) represses seed germination downstream of phyB. Here, we identify a positive regulator of phyB-dependent seed germination, long hypocotyl in far-red1 (HFR1). HFR1 blocks PIF1 transcriptional activity by forming a heterodimer with PIF1 that prevents PIF1 from binding to DNA. Our whole-genomic analysis shows that HFR1 and PIF1 oppositely mediate the light-regulated transcriptome in imbibed seeds. Through the HFR1-PIF1 module, light regulates expression of numerous genes involved in cell wall loosening, cell division, and hormone pathways to initiate seed germination. The functionally antagonistic HFR1-PIF1 pair constructs a fail-safe mechanism for fine-tuning seed germination during low-level illumination, ensuring a rapid response to favorable environmental changes. This study identifies the HFR1-PIF1 pair as a central module directing the whole genomic transcriptional network to rapidly initiate light-induced seed germination.
Collapse
Affiliation(s)
- Hui Shi
- Peking-Yale Joint Center for Plant Molecular Genetics and Agro-biotechnology, College of Life Sciences, Peking University, Beijing 100871, China
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, Connecticut 06520
| | - Shangwei Zhong
- Peking-Yale Joint Center for Plant Molecular Genetics and Agro-biotechnology, College of Life Sciences, Peking University, Beijing 100871, China
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, Connecticut 06520
| | - Xiaorong Mo
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, Connecticut 06520
| | - Na Liu
- Yale Stem Cell Center and Department of Cell Biology, Yale School of Medicine, New Haven, Connecticut 06519
| | - Cynthia D. Nezames
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, Connecticut 06520
| | - Xing Wang Deng
- Peking-Yale Joint Center for Plant Molecular Genetics and Agro-biotechnology, College of Life Sciences, Peking University, Beijing 100871, China
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, Connecticut 06520
- Address correspondence to
| |
Collapse
|
100
|
Lariguet P, Ranocha P, De Meyer M, Barbier O, Penel C, Dunand C. Identification of a hydrogen peroxide signalling pathway in the control of light-dependent germination in Arabidopsis. PLANTA 2013; 238:381-95. [PMID: 23716184 DOI: 10.1007/s00425-013-1901-5] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2013] [Accepted: 05/14/2013] [Indexed: 05/18/2023]
Abstract
Germination is controlled by external factors, such as temperature, water, light and by hormone balance. Recently, reactive oxygen species (ROS) have been shown to act as messengers during plant development, stress responses and programmed cell death. We analyzed the role of ROS during germination and demonstrated that ROS in addition to their role as cell wall loosening factor are essential signalling molecules in this process. Indeed, we showed that ROS are released prior to endosperm rupture, that their production is required for germination, and that class III peroxidases, as ROS level regulators, colocalized with ROS production. Among ROS, H2O2 modifies, during germination early steps, the expression of genes encoding for enzymes regulating ROS levels. This pointing out a regulatory feedback loop for ROS production. Measurements of endogenous levels of ROS following application of GA and ABA suggested that ABA inhibits germination by repressing ROS accumulation, and that, conversely, GA triggers germination by promoting an increase of ROS levels. We followed the early visible steps of germination (testa and endosperm rupture) in Arabidopsis seeds treated by specific ROS scavengers and as the light quality perception is necessary for a regular germination, we examined the germination in presence of exogenous H2O2 in different light qualities. H2O2 either promoted germination or repressed germination depending on the light wavelengths, showing that H2O2 acts as a signal molecule regulating germination in a light-dependent manner. Using photoreceptors null-mutants and GA-deficient mutants, we showed that H2O2-dependent promotion of germination relies on phytochrome signalling, but not on cryptochrome signalling, and that ROS signalling requires GA signalling.
Collapse
Affiliation(s)
- Patricia Lariguet
- Laboratory of Molecular Biology of Higher Plants, University of Geneva, Quai Ernest-Ansermet 30, Geneva 4, Switzerland
| | | | | | | | | | | |
Collapse
|