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Kim S, Huh SM, Han HJ, Lee GS, Hwang YS, Cho MH, Kim BG, Song JS, Chung JH, Nam MH, Ji H, Kim KH, Yoon IS. A rice seed-specific glycine-rich protein OsDOR1 interacts with GID1 to repress GA signaling and regulates seed dormancy. PLANT MOLECULAR BIOLOGY 2023; 111:523-539. [PMID: 36973492 DOI: 10.1007/s11103-023-01343-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Accepted: 02/20/2023] [Indexed: 06/18/2023]
Abstract
Seed dormancy is an important agronomic trait under the control of complex genetic and environmental interactions, which have not been yet comprehensively understood. From the field screening of rice mutant library generated by a Ds transposable element, we identified a pre-harvest sprouting (PHS) mutant dor1. This mutant has a single insertion of Ds element at the second exon of OsDOR1 (LOC_Os03g20770), which encodes a novel seed-specific glycine-rich protein. This gene successfully complemented the PHS phenotype of dor1 mutant and its ectopic expression enhanced seed dormancy. Here, we demonstrated that OsDOR1 protein binds to the GA receptor protein, OsGID1 in rice protoplasts, and interrupts with the formation OsGID1-OsSLR1 complex in yeast cells. Co-expression of OsDOR1 with OsGID1 in rice protoplasts attenuated the GA-dependent degradation of OsSLR1, the key repressor of GA signaling. We showed the endogenous OsSLR1 protein level in the dor1 mutant seeds is significantly lower than that of wild type. The dor1 mutant featured a hypersensitive GA-response of α-amylase gene expression during seed germination. Based on these findings, we suggest that OsDOR1 is a novel negative player of GA signaling operated in the maintenance of seed dormancy. Our findings provide a novel source of PHS resistance.
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Affiliation(s)
- Sooyeon Kim
- Gene Engineering Division, Rural Development Administration, National Institute of Agricultural Sciences, Jeonju, 55365, Republic of Korea
| | - Sun Mi Huh
- Gene Engineering Division, Rural Development Administration, National Institute of Agricultural Sciences, Jeonju, 55365, Republic of Korea
- Department of Medical and Biological Sciences, Institute of Convergence Science & Technology, The Catholic University of Korea, Bucheon, 14662, Republic of Korea
| | - Hay Ju Han
- Gene Engineering Division, Rural Development Administration, National Institute of Agricultural Sciences, Jeonju, 55365, Republic of Korea
| | - Gang Seob Lee
- Biosafety Division, Rural Development Administration, National Institute of Agricultural Sciences, Jeonju, 55365, Republic of Korea
| | - Yong-Sic Hwang
- Department of Systems Biotechnology, Konkuk University, Seoul, 05029, Republic of Korea
| | - Mi Hyun Cho
- Gene Engineering Division, Rural Development Administration, National Institute of Agricultural Sciences, Jeonju, 55365, Republic of Korea
| | - Beom-Gi Kim
- Metabolic Engineering Division, National Institute of Agricultural Sciences, Jeonju, 55365, Republic of Korea
| | - Ji Sun Song
- Gene Engineering Division, Rural Development Administration, National Institute of Agricultural Sciences, Jeonju, 55365, Republic of Korea
| | - Joo Hee Chung
- Seoul Center, Korea Basic Science Institute (KBSI), Seoul, 02841, Republic of Korea
| | - Myung Hee Nam
- Seoul Center, Korea Basic Science Institute (KBSI), Seoul, 02841, Republic of Korea
| | - Hyeonso Ji
- Gene Engineering Division, Rural Development Administration, National Institute of Agricultural Sciences, Jeonju, 55365, Republic of Korea
| | - Kyung-Hwan Kim
- Gene Engineering Division, Rural Development Administration, National Institute of Agricultural Sciences, Jeonju, 55365, Republic of Korea
| | - In Sun Yoon
- Gene Engineering Division, Rural Development Administration, National Institute of Agricultural Sciences, Jeonju, 55365, Republic of Korea.
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Che R, Hu B, Wang W, Xiao Y, Liu D, Yin W, Tong H, Chu C. POLLEN STERILITY, a novel suppressor of cell division, is required for timely tapetal programmed cell death in rice. SCIENCE CHINA-LIFE SCIENCES 2021; 65:1235-1247. [PMID: 34767152 DOI: 10.1007/s11427-021-2011-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Accepted: 09/18/2021] [Indexed: 11/28/2022]
Abstract
Timely programmed cell death (PCD) of the tapetum supplying nutrients to microspores is a prerequisite for normal pollen development. Here we identified a unique mutant of rice (Oryza sativa L.), pollen sterility (post), which showed aborted pollens accompanied with extra-large husks. Due to failure of timely PCD of tapetal cells, post exhibited abnormal pollen wall patterning and defective pollen grains. By map-based cloning, we identified a causal gene, POST, encoding a novel protein which is ubiquitously localized in cells. RNA in situ hybridization showed that POST is highly detected in the tapetum and microspores at stages 8 and 9. Transcriptome analysis indicated that POST could function as an important regulator of the metabolic process involved in tapetal PCD. Compared with wild-type rice, post mutant has an increased cell number resulting from elevated expression of cell cycle associated genes in grain husks. Overexpression of POST inhibits grain size in wild type, while appropriate expression of POST in post mutant can recover the seed fertility but has little effect on the large grains, illustrating that fine-tuning of POST expression could be a potential strategy for rice yield improvement. The connection between cell division and cell death conferred by POST provides novel insights into the understanding of the tapetal PCD process.
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Affiliation(s)
- Ronghui Che
- State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, the Innovative Academy for Seed Design, Chinese Academy of Sciences, Beijing, 100101, China.,School of Biological and Science Technology, University of Jinan, Jinan, 250022, China
| | - Bin Hu
- State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, the Innovative Academy for Seed Design, Chinese Academy of Sciences, Beijing, 100101, China.,College of Agriculture, South China Agricultural University, Guangzhou, 510642, China
| | - Wei Wang
- State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, the Innovative Academy for Seed Design, Chinese Academy of Sciences, Beijing, 100101, China.,College of Agriculture, South China Agricultural University, Guangzhou, 510642, China
| | - Yunhua Xiao
- State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, the Innovative Academy for Seed Design, Chinese Academy of Sciences, Beijing, 100101, China
| | - Dapu Liu
- National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Wenchao Yin
- National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Hongning Tong
- National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.
| | - Chengcai Chu
- State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, the Innovative Academy for Seed Design, Chinese Academy of Sciences, Beijing, 100101, China.
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3
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Yuan G, Lu H, Tang D, Hassan MM, Li Y, Chen JG, Tuskan GA, Yang X. Expanding the application of a UV-visible reporter for transient gene expression and stable transformation in plants. HORTICULTURE RESEARCH 2021; 8:234. [PMID: 34719678 PMCID: PMC8558336 DOI: 10.1038/s41438-021-00663-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Revised: 07/25/2021] [Accepted: 08/01/2021] [Indexed: 05/08/2023]
Abstract
Green fluorescent protein (GFP) has been widely used for monitoring gene expression and protein localization in diverse organisms. However, highly sensitive imaging equipment, like fluorescence microscope, is usually required for the visualization of GFP, limitings its application to fixed locations in samples. A reporter that can be visualized in real-time regardless the shape, size and location of the target samples will increase the flexibility and efficiency of research work. Here, we report the application of a GFP-like protein, called eYGFPuv, in both transient expression and stable transformation, in two herbaceous plant species (Arabidopsis and tobacco) and two woody plant species (poplar and citrus). We observed bright fluorescence under UV light in all of the four plant species without any effects on plant growth or development. eYGFPuv was shown to be effective for imaging transient expression in leaf and root tissues. With a focus on in vitro transformation, we demonstrated that the transgenic events expressing 1x eYGFPuv could be easily identified visually during the callus stage and the shoot stage, enabling early and efficient selection of transformants. Furthermore, whole-plant level visualization of eYGFPuv revealed its ubiquitous stability in transgenic plants. In addition, our transformation experiments showed that eYGFPuv can also be used to select transgenic plants without antibiotics. This work demonstrates the feasibility of utilizing 1x eYGFPuv in studies of gene expression and plant transformation in diverse plants.
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Affiliation(s)
- Guoliang Yuan
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
- The Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Haiwei Lu
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Dan Tang
- Department of Plant Science and Landscape Architecture, University of Connecticut, Storrs, CT, 06269, USA
- National Center for Citrus Improvement, College of Horticulture, Hunan Agricultural University, Changsha, 410128, Hunan, China
| | - Md Mahmudul Hassan
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
- The Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
- Department of Genetics and Plant Breeding, Patuakhali Science and Technology University, Dumki, Patuakhali, 8602, Bangladesh
| | - Yi Li
- Department of Plant Science and Landscape Architecture, University of Connecticut, Storrs, CT, 06269, USA
| | - Jin-Gui Chen
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
- The Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Gerald A Tuskan
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA.
- The Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA.
| | - Xiaohan Yang
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA.
- The Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA.
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Tai L, Wang HJ, Xu XJ, Sun WH, Ju L, Liu WT, Li WQ, Sun J, Chen KM. Pre-harvest sprouting in cereals: genetic and biochemical mechanisms. JOURNAL OF EXPERIMENTAL BOTANY 2021; 72:2857-2876. [PMID: 33471899 DOI: 10.1093/jxb/erab024] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Accepted: 01/18/2021] [Indexed: 05/22/2023]
Abstract
With the growth of the global population and the increasing frequency of natural disasters, crop yields must be steadily increased to enhance human adaptability to risks. Pre-harvest sprouting (PHS), a term mainly used to describe the phenomenon in which grains germinate on the mother plant directly before harvest, is a serious global problem for agricultural production. After domestication, the dormancy level of cultivated crops was generally lower than that of their wild ancestors. Although the shortened dormancy period likely improved the industrial performance of cereals such as wheat, barley, rice, and maize, the excessive germination rate has caused frequent PHS in areas with higher rainfall, resulting in great economic losses. Here, we systematically review the causes of PHS and its consequences, the major indicators and methods for PHS assessment, and emphasize the biological significance of PHS in crop production. Wheat quantitative trait loci functioning in the control of PHS are also comprehensively summarized in a meta-analysis. Finally, we use Arabidopsis as a model plant to develop more complete PHS regulatory networks for wheat. The integration of this information is conducive to the development of custom-made cultivated lines suitable for different demands and regions, and is of great significance for improving crop yields and economic benefits.
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Affiliation(s)
- Li Tai
- State Key Laboratory of Crop Stress Biology in Arid Areas, College of Life Sciences, Northwest A&F University, Yangling 712100, Shaanxi, China
| | - Hong-Jin Wang
- State Key Laboratory of Crop Stress Biology in Arid Areas, College of Life Sciences, Northwest A&F University, Yangling 712100, Shaanxi, China
| | - Xiao-Jing Xu
- State Key Laboratory of Crop Stress Biology in Arid Areas, College of Life Sciences, Northwest A&F University, Yangling 712100, Shaanxi, China
| | - Wei-Hang Sun
- State Key Laboratory of Crop Stress Biology in Arid Areas, College of Life Sciences, Northwest A&F University, Yangling 712100, Shaanxi, China
| | - Lan Ju
- State Key Laboratory of Crop Stress Biology in Arid Areas, College of Life Sciences, Northwest A&F University, Yangling 712100, Shaanxi, China
| | - Wen-Ting Liu
- State Key Laboratory of Crop Stress Biology in Arid Areas, College of Life Sciences, Northwest A&F University, Yangling 712100, Shaanxi, China
| | - Wen-Qiang Li
- State Key Laboratory of Crop Stress Biology in Arid Areas, College of Life Sciences, Northwest A&F University, Yangling 712100, Shaanxi, China
| | - Jiaqiang Sun
- National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Kun-Ming Chen
- State Key Laboratory of Crop Stress Biology in Arid Areas, College of Life Sciences, Northwest A&F University, Yangling 712100, Shaanxi, China
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5
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Xu F, Tang J, Gao S, Cheng X, Du L, Chu C. Control of rice pre-harvest sprouting by glutaredoxin-mediated abscisic acid signaling. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2019; 100:1036-1051. [PMID: 31436865 DOI: 10.1111/tpj.14501] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Revised: 07/27/2019] [Accepted: 08/07/2019] [Indexed: 05/18/2023]
Abstract
Pre-harvest sprouting (PHS) is one of the major problems in cereal production worldwide, which causes significant losses of both yield and quality; however, the molecular mechanism underlying PHS remains largely unknown. Here, we identified a dominant PHS mutant phs9-D. The corresponding gene PHS9 encodes a higher plant unique CC-type glutaredoxin and is specifically expressed in the embryo at the late embryogenesis stage, implying that PHS9 plays some roles in the late stage of seed development. Yeast two-hybrid screening showed that PHS9 could interact with OsGAP, which is an interaction partner of the abscicic acid (ABA) receptor OsRCAR1. PHS9- or OsGAP overexpression plants showed reduced ABA sensitivity in seed germination, whereas PHS9 or OsGAP knock-out mutant plants showed increased ABA sensitivity in seed germination, suggesting that PHS9 and OsGAP acted as negative regulators in ABA signaling during seed germination. Interestingly, the germination of PHS9 and OsGAP overexpression or knock-out plant seeds was weakly promoted by H2 O2 , implying that PHS9 and OsGAP could affect reactive oxygen species (ROS) signaling during seed germination. These results indicate that PHS9 plays an important role in the regulation of rice PHS through the integration of ROS signaling and ABA signaling.
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Affiliation(s)
- Fan Xu
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing, China
- Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, China
| | - Jiuyou Tang
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing, China
| | - Shaopei Gao
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing, China
| | - Xi Cheng
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing, China
| | - Lin Du
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing, China
| | - Chengcai Chu
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing, China
- College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing, China
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6
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Mutation of a histidine-rich calcium-binding-protein gene in wheat confers resistance to Fusarium head blight. Nat Genet 2019; 51:1106-1112. [PMID: 31182810 DOI: 10.1038/s41588-019-0426-7] [Citation(s) in RCA: 133] [Impact Index Per Article: 26.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2017] [Accepted: 04/23/2019] [Indexed: 11/08/2022]
Abstract
Head or ear blight, mainly caused by Fusarium species, can devastate almost all staple cereal crops (particularly wheat), resulting in great economic loss and imposing health threats on both human beings and livestock1-3. However, achievement in breeding for highly resistant cultivars is still not satisfactory. Here, we isolated the major-effect wheat quantitative trait locus, Qfhs.njau-3B, which confers head blight resistance, and showed that it is the same as the previously designated Fhb1. Fhb1 results from a rare deletion involving the 3' exon of the histidine-rich calcium-binding-protein gene on chromosome 3BS. Both wheat and Arabidopsis transformed with the Fhb1 sequence showed enhanced resistance to Fusarium graminearum spread. The translation products of this gene's homologs among plants are well conserved and might be essential for plant growth and development. Fhb1 could be useful not only for curbing Fusarium head blight in grain crops but also for improving other plants vulnerable to Fusarium species.
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Xiao Y, Liu D, Zhang G, Gao S, Liu L, Xu F, Che R, Wang Y, Tong H, Chu C. Big Grain3, encoding a purine permease, regulates grain size via modulating cytokinin transport in rice. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2019; 61:581-597. [PMID: 30267474 DOI: 10.1111/jipb.12727] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Accepted: 09/21/2018] [Indexed: 05/20/2023]
Abstract
Grain size is an important agronomic trait affecting grain yield, but the underlying molecular mechanisms remain to be elucidated. Here, we isolated a dominant mutant, big grain3 (bg3-D), which exhibits a remarkable increase of grain size caused by activation of the PURINE PERMEASE gene, OsPUP4. BG3/OsPUP4 is predominantly expressed in vascular tissues and is specifically suppressed by exogenous cytokinin application. Hormone profiling revealed that the distribution of different cytokinin forms, in roots and shoots of the bg3-D mutant, is altered. Quantitative reverse transcription-PCR (qRT-PCR) analysis indicated that expression of rice cytokinin type-A RESPONSE REGULATOR (OsRR) genes is enhanced in the roots of the bg3-D mutant. These results suggest that OsPUP4 might contribute to the long-distance transport of cytokinin, by reinforcing cytokinin loading into vascular bundle cells. Furthermore, plants overexpressing OsPUP7, the closest homolog of OsPUP4, also exhibited a similar phenotype to the bg3-D mutant. Interestingly, subcellular localization demonstrated that OsPUP4 was localized on the plasma membrane, whereas OsPUP7 was localized to the endoplasmic reticulum. Based on these findings, we propose that OsPUP4 and OsPUP7 function in a linear pathway to direct cytokinin cell-to-cell transport, affecting both its long-distance movement and local allocation.
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Affiliation(s)
- Yunhua Xiao
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, the Chinese Academy of Sciences, Beijing 100101, China
| | - Dapu Liu
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, the Chinese Academy of Sciences, Beijing 100101, China
| | - Guoxia Zhang
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, the Chinese Academy of Sciences, Beijing 100101, China
| | - Shaopei Gao
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, the Chinese Academy of Sciences, Beijing 100101, China
| | - Linchuan Liu
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, the Chinese Academy of Sciences, Beijing 100101, China
| | - Fan Xu
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, the Chinese Academy of Sciences, Beijing 100101, China
| | - Ronghui Che
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, the Chinese Academy of Sciences, Beijing 100101, China
| | - Yiqin Wang
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, the Chinese Academy of Sciences, Beijing 100101, China
| | - Hongning Tong
- National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Sciences, the Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Chengcai Chu
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, the Chinese Academy of Sciences, Beijing 100101, China
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Rosa MTG, Almeida DM, Pires IS, da Rosa Farias D, Martins AG, da Maia LC, de Oliveira AC, Saibo NJM, Oliveira MM, Abreu IA. Insights into the transcriptional and post-transcriptional regulation of the rice SUMOylation machinery and into the role of two rice SUMO proteases. BMC PLANT BIOLOGY 2018; 18:349. [PMID: 30541427 PMCID: PMC6291987 DOI: 10.1186/s12870-018-1547-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Accepted: 11/20/2018] [Indexed: 05/21/2023]
Abstract
BACKGROUND SUMOylation is an essential eukaryotic post-translation modification that, in plants, regulates numerous cellular processes, ranging from seed development to stress response. Using rice as a model crop plant, we searched for potential regulatory points that may influence the activity of the rice SUMOylation machinery genes. RESULTS We analyzed the presence of putative cis-acting regulatory elements (CREs) within the promoter regions of the rice SUMOylation machinery genes and found CREs related to different cellular processes, including hormone signaling. We confirmed that the transcript levels of genes involved in target-SUMOylation, containing ABA- and GA-related CREs, are responsive to treatments with these hormones. Transcriptional analysis in Nipponbare (spp. japonica) and LC-93-4 (spp. indica), showed that the transcript levels of all studied genes are maintained in the two subspecies, under normal growth. OsSUMO3 is an exceptional case since it is expressed at low levels or is not detectable at all in LC-93-4 roots and shoots, respectively. We revealed post-transcriptional regulation by alternative splicing (AS) for all genes studied, except for SUMO coding genes, OsSIZ2, OsOTS3, and OsELS2. Some AS forms have the potential to alter protein domains and catalytic centers. We also performed the molecular and phenotypic characterization of T-DNA insertion lines of some of the genes under study. Knockouts of OsFUG1 and OsELS1 showed increased SUMOylation levels and non-overlapping phenotypes. The fug1 line showed a dwarf phenotype, and significant defects in fertility, seed weight, and panicle architecture, while the els1 line showed early flowering and decreased plant height. We suggest that OsELS1 is an ortholog of AtEsd4, which was also supported by our phylogenetic analysis. CONCLUSIONS Overall, we provide a comprehensive analysis of the rice SUMOylation machinery and discuss possible effects of the regulation of these genes at the transcriptional and post-transcriptional level. We also contribute to the characterization of two rice SUMO proteases, OsELS1 and OsFUG1.
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Affiliation(s)
- Margarida T. G. Rosa
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa (ITQB-UNL), Av. da República, 2780-157 Oeiras, Portugal
| | - Diego M. Almeida
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa (ITQB-UNL), Av. da República, 2780-157 Oeiras, Portugal
- IBET, Av. da República, 2780-157 Oeiras, Portugal
- Laboratoire de Biochimie et Physiologie Moléculaire des Plantes (BPMP), Institut National de la Recherche Agronomique (INRA), Université de Montpellier (UM), Montpellier, France
| | - Inês S. Pires
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa (ITQB-UNL), Av. da República, 2780-157 Oeiras, Portugal
- Frontiers Media SA, Avenue du Tribunal-Fédéral 34, CH-1015 Lausanne, Switzerland
| | - Daniel da Rosa Farias
- Plant Genomics and Breeding Center, Faculdade de Agronomia Eliseu Maciel, Universidade Federal de Pelotas, Pelotas, RS Brazil
| | - Alice G. Martins
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa (ITQB-UNL), Av. da República, 2780-157 Oeiras, Portugal
| | - Luciano Carlos da Maia
- Plant Genomics and Breeding Center, Faculdade de Agronomia Eliseu Maciel, Universidade Federal de Pelotas, Pelotas, RS Brazil
| | - António Costa de Oliveira
- Plant Genomics and Breeding Center, Faculdade de Agronomia Eliseu Maciel, Universidade Federal de Pelotas, Pelotas, RS Brazil
| | - Nelson J. M. Saibo
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa (ITQB-UNL), Av. da República, 2780-157 Oeiras, Portugal
| | - M. Margarida Oliveira
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa (ITQB-UNL), Av. da República, 2780-157 Oeiras, Portugal
| | - Isabel A. Abreu
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa (ITQB-UNL), Av. da República, 2780-157 Oeiras, Portugal
- IBET, Av. da República, 2780-157 Oeiras, Portugal
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9
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Du L, Xu F, Fang J, Gao S, Tang J, Fang S, Wang H, Tong H, Zhang F, Chu J, Wang G, Chu C. Endosperm sugar accumulation caused by mutation of PHS8/ISA1 leads to pre-harvest sprouting in rice. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2018; 95:545-556. [PMID: 29775500 DOI: 10.1111/tpj.13970] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Revised: 05/07/2018] [Accepted: 05/09/2018] [Indexed: 05/18/2023]
Abstract
Pre-harvest sprouting (PHS) is an unfavorable trait in cereal crops that could seriously decrease grain yield and quality. Although some PHS-associated quantitative trait loci or genes in cereals have been reported, the molecular mechanism underlying PHS remains largely elusive. Here, we characterized a rice mutant, phs8, which exhibits PHS phenotype accompanied by sugary endosperm. Map-based cloning revealed that PHS8 encodes a starch debranching enzyme named isoamylase1. Mutation in PHS8 resulted in the phytoglycogen breakdown and sugar accumulation in the endosperm. Intriguingly, with increase of sugar contents, decreased expression of OsABI3 and OsABI5 as well as reduced sensitivity to abscisic acid (ABA) were found in the phs8 mutant. Using rice suspension cell system, we confirmed that exogenous sugar is sufficient to suppress the expression of both OsABI3 and OsABI5. Furthermore, overexpression of OsABI3 or OsABI5 could partially rescue the PHS phenotype of phs8. Therefore, our study presents important evidence supporting that endosperm sugar not only acts as an essential energy source for seed germination but also determines seed dormancy and germination by affecting ABA signaling.
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Affiliation(s)
- Lin Du
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Fan Xu
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Jun Fang
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Shaopei Gao
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Jiuyou Tang
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Shuang Fang
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Hongru Wang
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Hongning Tong
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Fengxia Zhang
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Jinfang Chu
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Guodong Wang
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Chengcai Chu
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China
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10
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Activation of Big Grain1 significantly improves grain size by regulating auxin transport in rice. Proc Natl Acad Sci U S A 2015; 112:11102-7. [PMID: 26283354 DOI: 10.1073/pnas.1512748112] [Citation(s) in RCA: 202] [Impact Index Per Article: 22.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Grain size is one of the key factors determining grain yield. However, it remains largely unknown how grain size is regulated by developmental signals. Here, we report the identification and characterization of a dominant mutant big grain1 (Bg1-D) that shows an extra-large grain phenotype from our rice T-DNA insertion population. Overexpression of BG1 leads to significantly increased grain size, and the severe lines exhibit obviously perturbed gravitropism. In addition, the mutant has increased sensitivities to both auxin and N-1-naphthylphthalamic acid, an auxin transport inhibitor, whereas knockdown of BG1 results in decreased sensitivities and smaller grains. Moreover, BG1 is specifically induced by auxin treatment, preferentially expresses in the vascular tissue of culms and young panicles, and encodes a novel membrane-localized protein, strongly suggesting its role in regulating auxin transport. Consistent with this finding, the mutant has increased auxin basipetal transport and altered auxin distribution, whereas the knockdown plants have decreased auxin transport. Manipulation of BG1 in both rice and Arabidopsis can enhance plant biomass, seed weight, and yield. Taking these data together, we identify a novel positive regulator of auxin response and transport in a crop plant and demonstrate its role in regulating grain size, thus illuminating a new strategy to improve plant productivity.
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11
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Abstract
The small grass Brachypodium distachyon has attributes that make it an excellent model for the development and improvement of cereal crops and bioenergy feedstocks. To realize the potential of this system, many tools have been developed (e.g., the complete genome sequence, a large collection of natural accessions, a high density genetic map, BAC libraries, EST sequences, microarrays, etc.). In this chapter, we describe a high-efficiency transformation system, an essential tool for a modern model system. Our method utilizes the natural ability of Agrobacterium tumefaciens to transfer a well-defined region of DNA from its tumor-inducing (Ti) plasmid DNA into the genome of a host plant cell. Immature embryos dissected out of developing B. distachyon seeds generate an embryogenic callus that serves as the source material for transformation and regeneration of transgenic plants. Embryogenic callus is cocultivated with A. tumefaciens carrying a recombinant plasmid containing the desired transformation sequence. Following cocultivation, callus is transferred to selective media to identify and amplify the transgenic tissue. After 2-5 weeks on selection media, transgenic callus is moved onto regeneration media for 2-4 weeks until plantlets emerge. Plantlets are grown in tissue culture until they develop roots and are transplanted into soil. Transgenic plants can be transferred to soil 6-10 weeks after cocultivation. Using this method with hygromycin selection, transformation efficiencies average 42 %, and it is routinely observed that 50-75 % of cocultivated calluses produce transgenic plants. The time from dissecting out embryos to having the first transgenic plants in soil is 14-18 weeks, and the time to harvesting transgenic seeds is 20-31 weeks.
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Affiliation(s)
- Jennifer N Bragg
- USDA-ARS, Western Regional Research Center, Albany, CA, 94710, USA
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12
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Hu B, Wang W, Deng K, Li H, Zhang Z, Zhang L, Chu C. MicroRNA399 is involved in multiple nutrient starvation responses in rice. FRONTIERS IN PLANT SCIENCE 2015; 6:188. [PMID: 25852730 PMCID: PMC4371656 DOI: 10.3389/fpls.2015.00188] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2014] [Accepted: 03/08/2015] [Indexed: 05/20/2023]
Abstract
The increasing evidences have revealed that microRNAs (miRNAs) play significant role in nutrient stress response. Previously, miR399 was documented to be induced by phosphorus (P) starvation and involved in regulating P starvation responses. To further investigate the function of miR399 in rice (Oryza sativa L.), we performed GeneChip analysis with OsmiR399 over-expressing plants. Interestingly, our results showed that, besides P starvation responsive genes, the expression of a number of genes involved in iron (Fe), potassium (K), sodium (Na), and calcium (Ca) absorption was dramatically up-regulated in OsmiR399 over-expressing plants. Consistently, the concentrations of Fe, K, Na, and Ca were also increased in OsmiR399 over-expressing plants. The expression of OsmiR399 was also up-regulated by these nutrient starvations, respectively. Moreover, the loss-of-function of LTN1, the down-stream target of OsmiR399, also resulted in the increase of multiple metal elements and the up-regulation of the absorption related genes. These results indicated that OsmiR399 participates in the regulation of multiple nutrient starvation responses, which also gives new view on understanding the interaction among different nutrients mediated by miR399.
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Affiliation(s)
- Bin Hu
- State Key Laboratory of Plant Genomics, National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of SciencesBeijing, China
| | - Wei Wang
- State Key Laboratory of Plant Genomics, National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of SciencesBeijing, China
- University of Chinese Academy of SciencesBeijing, China
| | - Kun Deng
- School of Agriculture, Henan University of Science and TechnologyLuoyang, China
| | - Hua Li
- State Key Laboratory of Plant Genomics, National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of SciencesBeijing, China
- University of Chinese Academy of SciencesBeijing, China
| | - Zhihua Zhang
- State Key Laboratory of Plant Genomics, National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of SciencesBeijing, China
- University of Chinese Academy of SciencesBeijing, China
| | - Lianhe Zhang
- School of Agriculture, Henan University of Science and TechnologyLuoyang, China
| | - Chengcai Chu
- State Key Laboratory of Plant Genomics, National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of SciencesBeijing, China
- *Correspondence: Chengcai Chu, State Key Laboratory of Plant Genomics, National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beichen West Road No.1, Beijing 100101, China
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13
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Gao S, Fang J, Xu F, Wang W, Sun X, Chu J, Cai B, Feng Y, Chu C. CYTOKININ OXIDASE/DEHYDROGENASE4 Integrates Cytokinin and Auxin Signaling to Control Rice Crown Root Formation. PLANT PHYSIOLOGY 2014; 165:1035-1046. [PMID: 24808099 PMCID: PMC4081320 DOI: 10.1104/pp.114.238584] [Citation(s) in RCA: 143] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2014] [Accepted: 05/03/2014] [Indexed: 05/17/2023]
Abstract
Crown roots constitute the majority of the rice (Oryza sativa) root system and play an important role in rice growth and development. However, the molecular mechanism of crown root formation in rice is not well understood. Here, we characterized a rice dominant mutant, root enhancer1 (ren1-D), which was observed to exhibit a more robust root system, increased crown root number, and reduced plant height. Molecular and genetic analyses revealed that these phenotypes are caused by the activation of a cytokinin oxidase/dehydrogenase (CKX) family gene, OsCKX4. Subcellular localization demonstrated that OsCKX4 is a cytosolic isoform of CKX. OsCKX4 is predominantly expressed in leaf blades and roots. It is the dominant CKX, preferentially expressed in the shoot base where crown root primordia are produced, underlining its role in root initiation. OsCKX4 is induced by exogenous auxin and cytokinin in the roots. Furthermore, one-hybrid assays revealed that OsCKX4 is a direct binding target of both the auxin response factor OsARF25 and the cytokinin response regulators OsRR2 and OsRR3. Overexpression and RNA interference of OsCKX4 confirmed that OsCKX4 plays a positive role in crown root formation. Moreover, expression analysis revealed a significant alteration in the expression of auxin-related genes in the ren1-D mutants, indicating that the OsCKX4 mediates crown root development by integrating the interaction between cytokinin and auxin. Transgenic plants harboring OsCKX4 under the control of the root-specific promoter RCc3 displayed enhanced root development without affecting their shoot parts, suggesting that this strategy could be a powerful tool in rice root engineering.
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Affiliation(s)
- Shaopei Gao
- Key Laboratory of Cell Proliferation and Regulation Biology of the Ministry of Education, College of Life Sciences, Beijing Normal University, Beijing 100875, China (S.G.);State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China (S.G., J.F., F.X., W.W., X.S., J.C., C.C.); andKey Laboratory of Analytical Chemistry for Biology and Medicine of the Ministry of Education, Department of Chemistry, Wuhan University, Wuhan 430072, China (B.C., Y.F.)
| | - Jun Fang
- Key Laboratory of Cell Proliferation and Regulation Biology of the Ministry of Education, College of Life Sciences, Beijing Normal University, Beijing 100875, China (S.G.);State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China (S.G., J.F., F.X., W.W., X.S., J.C., C.C.); andKey Laboratory of Analytical Chemistry for Biology and Medicine of the Ministry of Education, Department of Chemistry, Wuhan University, Wuhan 430072, China (B.C., Y.F.)
| | - Fan Xu
- Key Laboratory of Cell Proliferation and Regulation Biology of the Ministry of Education, College of Life Sciences, Beijing Normal University, Beijing 100875, China (S.G.);State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China (S.G., J.F., F.X., W.W., X.S., J.C., C.C.); andKey Laboratory of Analytical Chemistry for Biology and Medicine of the Ministry of Education, Department of Chemistry, Wuhan University, Wuhan 430072, China (B.C., Y.F.)
| | - Wei Wang
- Key Laboratory of Cell Proliferation and Regulation Biology of the Ministry of Education, College of Life Sciences, Beijing Normal University, Beijing 100875, China (S.G.);State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China (S.G., J.F., F.X., W.W., X.S., J.C., C.C.); andKey Laboratory of Analytical Chemistry for Biology and Medicine of the Ministry of Education, Department of Chemistry, Wuhan University, Wuhan 430072, China (B.C., Y.F.)
| | - Xiaohong Sun
- Key Laboratory of Cell Proliferation and Regulation Biology of the Ministry of Education, College of Life Sciences, Beijing Normal University, Beijing 100875, China (S.G.);State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China (S.G., J.F., F.X., W.W., X.S., J.C., C.C.); andKey Laboratory of Analytical Chemistry for Biology and Medicine of the Ministry of Education, Department of Chemistry, Wuhan University, Wuhan 430072, China (B.C., Y.F.)
| | - Jinfang Chu
- Key Laboratory of Cell Proliferation and Regulation Biology of the Ministry of Education, College of Life Sciences, Beijing Normal University, Beijing 100875, China (S.G.);State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China (S.G., J.F., F.X., W.W., X.S., J.C., C.C.); andKey Laboratory of Analytical Chemistry for Biology and Medicine of the Ministry of Education, Department of Chemistry, Wuhan University, Wuhan 430072, China (B.C., Y.F.)
| | - Baodong Cai
- Key Laboratory of Cell Proliferation and Regulation Biology of the Ministry of Education, College of Life Sciences, Beijing Normal University, Beijing 100875, China (S.G.);State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China (S.G., J.F., F.X., W.W., X.S., J.C., C.C.); andKey Laboratory of Analytical Chemistry for Biology and Medicine of the Ministry of Education, Department of Chemistry, Wuhan University, Wuhan 430072, China (B.C., Y.F.)
| | - Yuqi Feng
- Key Laboratory of Cell Proliferation and Regulation Biology of the Ministry of Education, College of Life Sciences, Beijing Normal University, Beijing 100875, China (S.G.);State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China (S.G., J.F., F.X., W.W., X.S., J.C., C.C.); andKey Laboratory of Analytical Chemistry for Biology and Medicine of the Ministry of Education, Department of Chemistry, Wuhan University, Wuhan 430072, China (B.C., Y.F.)
| | - Chengcai Chu
- Key Laboratory of Cell Proliferation and Regulation Biology of the Ministry of Education, College of Life Sciences, Beijing Normal University, Beijing 100875, China (S.G.);State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China (S.G., J.F., F.X., W.W., X.S., J.C., C.C.); andKey Laboratory of Analytical Chemistry for Biology and Medicine of the Ministry of Education, Department of Chemistry, Wuhan University, Wuhan 430072, China (B.C., Y.F.)
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14
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OsNAP connects abscisic acid and leaf senescence by fine-tuning abscisic acid biosynthesis and directly targeting senescence-associated genes in rice. Proc Natl Acad Sci U S A 2014; 111:10013-8. [PMID: 24951508 DOI: 10.1073/pnas.1321568111] [Citation(s) in RCA: 328] [Impact Index Per Article: 32.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
It has long been established that premature leaf senescence negatively impacts the yield stability of rice, but the underlying molecular mechanism driving this relationship remains largely unknown. Here, we identified a dominant premature leaf senescence mutant, prematurely senile 1 (ps1-D). PS1 encodes a plant-specific NAC (no apical meristem, Arabidopsis ATAF1/2, and cup-shaped cotyledon2) transcriptional activator, Oryza sativa NAC-like, activated by apetala3/pistillata (OsNAP). Overexpression of OsNAP significantly promoted senescence, whereas knockdown of OsNAP produced a marked delay of senescence, confirming the role of this gene in the development of rice senescence. OsNAP expression was tightly linked with the onset of leaf senescence in an age-dependent manner. Similarly, ChIP-PCR and yeast one-hybrid assays demonstrated that OsNAP positively regulates leaf senescence by directly targeting genes related to chlorophyll degradation and nutrient transport and other genes associated with senescence, suggesting that OsNAP is an ideal marker of senescence onset in rice. Further analysis determined that OsNAP is induced specifically by abscisic acid (ABA), whereas its expression is repressed in both aba1 and aba2, two ABA biosynthetic mutants. Moreover, ABA content is reduced significantly in ps1-D mutants, indicating a feedback repression of OsNAP on ABA biosynthesis. Our data suggest that OsNAP serves as an important link between ABA and leaf senescence. Additionally, reduced OsNAP expression leads to delayed leaf senescence and an extended grain-filling period, resulting in a 6.3% and 10.3% increase in the grain yield of two independent representative RNAi lines, respectively. Thus, fine-tuning OsNAP expression should be a useful strategy for improving rice yield in the future.
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15
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Lu G, Wang X, Liu J, Yu K, Gao Y, Liu H, Wang C, Wang W, Wang G, Liu M, Mao G, Li B, Qin J, Xia M, Zhou J, Liu J, Jiang S, Mo H, Cui J, Nagasawa N, Sivasankar S, Albertsen MC, Sakai H, Mazur BJ, Lassner MW, Broglie RM. Application of T-DNA activation tagging to identify glutamate receptor-like genes that enhance drought tolerance in plants. PLANT CELL REPORTS 2014; 33:617-31. [PMID: 24682459 DOI: 10.1007/s00299-014-1586-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2013] [Revised: 02/05/2014] [Accepted: 02/06/2014] [Indexed: 05/26/2023]
Abstract
A high-quality rice activation tagging population has been developed and screened for drought-tolerant lines using various water stress assays. One drought-tolerant line activated two rice glutamate receptor-like genes. Transgenic overexpression of the rice glutamate receptor-like genes conferred drought tolerance to rice and Arabidopsis. Rice (Oryza sativa) is a multi-billion dollar crop grown in more than one hundred countries, as well as a useful functional genetic tool for trait discovery. We have developed a population of more than 200,000 activation-tagged rice lines for use in forward genetic screens to identify genes that improve drought tolerance and other traits that improve yield and agronomic productivity. The population has an expected coverage of more than 90 % of rice genes. About 80 % of the lines have a single T-DNA insertion locus and this molecular feature simplifies gene identification. One of the lines identified in our screens, AH01486, exhibits improved drought tolerance. The AH01486 T-DNA locus is located in a region with two glutamate receptor-like genes. Constitutive overexpression of either glutamate receptor-like gene significantly enhances the drought tolerance of rice and Arabidopsis, thus revealing a novel function of this important gene family in plant biology.
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Affiliation(s)
- Guihua Lu
- Beijing Kaituo DNA Biotech Research Center, Co., Ltd., Beijing, 102206, China,
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16
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Guo X, Hou X, Fang J, Wei P, Xu B, Chen M, Feng Y, Chu C. The rice GERMINATION DEFECTIVE 1, encoding a B3 domain transcriptional repressor, regulates seed germination and seedling development by integrating GA and carbohydrate metabolism. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2013; 75:403-16. [PMID: 23581288 PMCID: PMC3813988 DOI: 10.1111/tpj.12209] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2013] [Revised: 04/08/2013] [Accepted: 04/11/2013] [Indexed: 05/19/2023]
Abstract
It has been shown that seed development is regulated by a network of transcription factors in Arabidopsis including LEC1 (LEAFY COTYLEDON1), L1L (LEC1-like) and the B3 domain factors LEC2, FUS3 (FUSCA3) and ABI3 (ABA-INSENSITIVE3); however, molecular and genetic regulation of seed development in cereals is poorly understood. To understand seed development and seed germination in cereals, a large-scale screen was performed using our T-DNA mutant population, and a mutant germination-defective1 (gd1) was identified. In addition to the severe germination defect, the gd1 mutant also shows a dwarf phenotype and abnormal flower development. Molecular and biochemical analyses revealed that GD1 encodes a B3 domain-containing transcription factor with repression activity. Consistent with the dwarf phenotype of gd1, expression of the gibberelic acid (GA) inactivation gene OsGA2ox3 is increased dramatically, accompanied by reduced expression of GA biosynthetic genes including OsGA20ox1, OsGA20ox2 and OsGA3ox2 in gd1, resulting in a decreased endogenous GA₄ level. Exogenous application of GA not only induced GD1 expression, but also partially rescued the dwarf phenotype of gd1. Furthermore, GD1 binds to the promoter of OsLFL1, a LEC2/FUS3-like gene of rice, via an RY element, leading to significant up-regulation of OsLFL1 and a large subset of seed maturation genes in the gd1 mutant. Plants over-expressing OsLFL1 partly mimic the gd1 mutant. In addition, expression of GD1 was induced under sugar treatment, and the contents of starch and soluble sugar are altered in the gd1 mutant. These data indicate that GD1 participates directly or indirectly in regulating GA and carbohydrate homeostasis, and further regulates rice seed germination and seedling development.
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Affiliation(s)
- Xiaoli Guo
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of SciencesBeijing, 100101, China
| | - Xiaomei Hou
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of SciencesBeijing, 100101, China
- Graduate University of the Chinese Academy of SciencesBeijing, 100049, China
| | - Jun Fang
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of SciencesBeijing, 100101, China
- For correspondence (e-mail or )
| | - Piwei Wei
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of SciencesBeijing, 100101, China
| | - Bo Xu
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of SciencesBeijing, 100101, China
- Graduate University of the Chinese Academy of SciencesBeijing, 100049, China
| | - Mingluan Chen
- Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education) Department of Chemistry, Wuhan UniversityWuhan, 430072, China
| | - Yuqi Feng
- Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education) Department of Chemistry, Wuhan UniversityWuhan, 430072, China
| | - Chengcai Chu
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of SciencesBeijing, 100101, China
- For correspondence (e-mail or )
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17
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Chang Y, Long T, Wu C. Effort and contribution of T-DNA Insertion mutant library for rice functional genomics research in China: review and perspective. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2012; 54:953-966. [PMID: 23020748 DOI: 10.1111/j.1744-7909.2012.01171.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
With the completion of the rice (Oryza sativa L.) genome-sequencing project, the rice research community proposed to characterize the function of every predicted gene in rice by 2020. One of the most effective and high-throughput strategies for studying gene function is to employ genetic mutations induced by insertion elements such as T-DNA or transposons. Since 1999, with support from the Ministry of Science and Technology of China for Rice Functional Genomics Programs, large-scale T-DNA insertion mutant populations have been generated in Huazhong Agricultural University, the Chinese Academy of Sciences and the Chinese Academy of Agricultural Sciences. Currently, a total of 372,346 mutant lines have been generated, and 58,226 T-DNA or Tos17 flanking sequence tags have been isolated. Using these mutant resources, more than 40 genes with potential applications in rice breeding have already been identified. These include genes involved in biotic or abiotic stress responses, nutrient metabolism, pollen development, and plant architecture. The functional analysis of these genes will not only deepen our understanding of the fundamental biological questions in rice, but will also offer valuable gene resources for developing Green Super Rice that is high-yielding with few inputs even under the poor growth conditions of many regions of Africa and Asia.
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Affiliation(s)
- Yuxiao Chang
- National Key Laboratory of Crop Genetic Improvement and National Center of Plant Gene Research-Wuhan, Huazhong Agricultural University, Wuhan 430070, China
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18
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Liu X, Li F, Tang J, Wang W, Zhang F, Wang G, Chu J, Yan C, Wang T, Chu C, Li C. Activation of the jasmonic acid pathway by depletion of the hydroperoxide lyase OsHPL3 reveals crosstalk between the HPL and AOS branches of the oxylipin pathway in rice. PLoS One 2012; 7:e50089. [PMID: 23209649 PMCID: PMC3510209 DOI: 10.1371/journal.pone.0050089] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2012] [Accepted: 10/15/2012] [Indexed: 01/31/2023] Open
Abstract
The allene oxide synthase (AOS) and hydroperoxide lyase (HPL) branches of the oxylipin pathway, which underlie the production of jasmonates and aldehydes, respectively, function in plant responses to a range of stresses. Regulatory crosstalk has been proposed to exist between these two signaling branches; however, there is no direct evidence of this. Here, we identified and characterized a jasmonic acid (JA) overproduction mutant, cea62, by screening a rice T-DNA insertion mutant library for lineages that constitutively express the AOS gene. Map-based cloning was used to identify the underlying gene as hydroperoxide lyase OsHPL3. HPL3 expression and the enzyme activity of its product, (E)-2-hexenal, were depleted in the cea62 mutant, which resulted in the dramatic overproduction of JA, the activation of JA signaling, and the emergence of the lesion mimic phenotype. A time-course analysis of lesion formation and of the induction of defense responsive genes in the cea62 mutant revealed that the activation of JA biosynthesis and signaling in cea62 was regulated in a developmental manner, as was OsHPL3 activity in the wild-type plant. Microarray analysis showed that the JA-governed defense response was greatly activated in cea62 and this plant exhibited enhanced resistance to the T1 strain of the bacterial blight pathogen Xanthomonasoryzaepvoryzae (Xoo). The wounding response was attenuated in cea62 plants during the early stages of development, but partially recovered when JA levels were elevated during the later stages. In contrast, the wounding response was not altered during the different developmental stages of wild-type plants. These findings suggest that these two branches of the oxylipin pathway exhibit crosstalk with regards to biosynthesis and signaling and cooperate with each other to function in diverse stress responses.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | - Chengcai Chu
- State Key Laboratory of Plant Genomics, National Centre for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, People's Republic of China
| | - Chuanyou Li
- State Key Laboratory of Plant Genomics, National Centre for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, People's Republic of China
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19
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Computation-assisted SiteFinding- PCR for isolating flanking sequence tags in rice. Biotechniques 2012; 51:421-3. [PMID: 22150334 DOI: 10.2144/000113787] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2011] [Accepted: 11/10/2011] [Indexed: 11/23/2022] Open
Abstract
SiteFinding-PCR is a method for isolating flanking sequence tags (FSTs) of T-DNA insertion lines, but the efficiency needs to be improved. Here we report a computation-assisted design for the random primers used in SiteFinding- PCR. A short sequence, GCATG, was screened from the rice genome and used as the 3' end of the random primer. When applying the optimized primer for isolating FSTs from 168 transgenic rice lines, we obtained 107 specific products, including 64 FSTs. The efficiency of obtaining FSTs using the modified version of SiteFinding-PCR increased by 73.0% compared with the method previously reported (P < 0.01, µ test). We also provide computational results for several other plant species such as maize, sorghum, Arabidopsis, foxtail millet, and Brachypodium based on the available genome data, so that the modified method could be easily adapted to other species.
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20
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Zhang FT, Fang J, Sun CH, Li RB, Luo XD, Xie JK, Deng XJ, Chu CC. Characterisation of a rice dwarf and twist leaf 1 (dtl1) mutant and fine mapping of DTL1 gene. YI CHUAN = HEREDITAS 2012; 34:79-86. [DOI: 10.3724/sp.j.1005.2012.00079] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Lin A, Wang Y, Tang J, Xue P, Li C, Liu L, Hu B, Yang F, Loake GJ, Chu C. Nitric oxide and protein S-nitrosylation are integral to hydrogen peroxide-induced leaf cell death in rice. PLANT PHYSIOLOGY 2012; 158:451-64. [PMID: 22106097 PMCID: PMC3252116 DOI: 10.1104/pp.111.184531] [Citation(s) in RCA: 202] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2011] [Accepted: 11/19/2011] [Indexed: 05/18/2023]
Abstract
Nitric oxide (NO) is a key redox-active, small molecule involved in various aspects of plant growth and development. Here, we report the identification of an NO accumulation mutant, nitric oxide excess1 (noe1), in rice (Oryza sativa), the isolation of the corresponding gene, and the analysis of its role in NO-mediated leaf cell death. Map-based cloning revealed that NOE1 encoded a rice catalase, OsCATC. Furthermore, noe1 resulted in an increase of hydrogen peroxide (H(2)O(2)) in the leaves, which consequently promoted NO production via the activation of nitrate reductase. The removal of excess NO reduced cell death in both leaves and suspension cultures derived from noe1 plants, implicating NO as an important endogenous mediator of H(2)O(2)-induced leaf cell death. Reduction of intracellular S-nitrosothiol (SNO) levels, generated by overexpression of rice S-nitrosoglutathione reductase gene (GSNOR1), which regulates global levels of protein S-nitrosylation, alleviated leaf cell death in noe1 plants. Thus, S-nitrosylation was also involved in light-dependent leaf cell death in noe1. Utilizing the biotin-switch assay, nanoliquid chromatography, and tandem mass spectrometry, S-nitrosylated proteins were identified in both wild-type and noe1 plants. NO targets identified only in noe1 plants included glyceraldehyde 3-phosphate dehydrogenase and thioredoxin, which have been reported to be involved in S-nitrosylation-regulated cell death in animals. Collectively, our data suggest that both NO and SNOs are important mediators in the process of H(2)O(2)-induced leaf cell death in rice.
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RLIN1, encoding a putative coproporphyrinogen III oxidase, is involved in lesion initiation in rice. J Genet Genomics 2011; 38:29-37. [PMID: 21338950 DOI: 10.1016/j.jcg.2010.12.001] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2010] [Revised: 10/17/2010] [Accepted: 10/20/2010] [Indexed: 01/15/2023]
Abstract
Lesion mimic is necrotic lesions on plant leaf or stem in the absence of pathogenic infection, and its exact biological mechanism is varied. By a large-scale screening of our T-DNA mutant population, we identified a mutant rice lesion initiation 1 (rlin1), which was controlled by a single nuclear recessive gene. Map-based cloning revealed that RLIN1 encoded a putative coproporphyrinogen III oxidase in tetrapyrrole biosynthesis pathway. Sequencing results showed that a G to T substitution occurred in the second exon of RLIN1 and led to a missense mutation from Asp to Tyr. Ectopic expression of RLIN1 could rescue rlin1 lesion mimic phenotype. Histochemical analysis demonstrated that lesion formation in rlin1 was light-dependent accompanied by reactive oxygen species accumulated. These results suggest that tetrapyrrole participates in lesion formation in rice.
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Li C, Wang Y, Liu L, Hu Y, Zhang F, Mergen S, Wang G, Schläppi MR, Chu C. A rice plastidial nucleotide sugar epimerase is involved in galactolipid biosynthesis and improves photosynthetic efficiency. PLoS Genet 2011; 7:e1002196. [PMID: 21829379 PMCID: PMC3145628 DOI: 10.1371/journal.pgen.1002196] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2011] [Accepted: 06/07/2011] [Indexed: 11/18/2022] Open
Abstract
Photosynthesis is the final determinator for crop yield. To gain insight into genes controlling photosynthetic capacity, we selected from our large T-DNA mutant population a rice stunted growth mutant with decreased carbon assimilate and yield production named photoassimilate defective1 (phd1). Molecular and biochemical analyses revealed that PHD1 encodes a novel chloroplast-localized UDP-glucose epimerase (UGE), which is conserved in the plant kingdom. The chloroplast localization of PHD1 was confirmed by immunoblots, immunocytochemistry, and UGE activity in isolated chloroplasts, which was approximately 50% lower in the phd1-1 mutant than in the wild type. In addition, the amounts of UDP-glucose and UDP-galactose substrates in chloroplasts were significantly higher and lower, respectively, indicating that PHD1 was responsible for a major part of UGE activity in plastids. The relative amount of monogalactosyldiacylglycerol (MGDG), a major chloroplast membrane galactolipid, was decreased in the mutant, while the digalactosyldiacylglycerol (DGDG) amount was not significantly altered, suggesting that PHD1 participates mainly in UDP-galactose supply for MGDG biosynthesis in chloroplasts. The phd1 mutant showed decreased chlorophyll content, photosynthetic activity, and altered chloroplast ultrastructure, suggesting that a correct amount of galactoglycerolipids and the ratio of glycolipids versus phospholipids are necessary for proper chloroplast function. Downregulated expression of starch biosynthesis genes and upregulated expression of sucrose cleavage genes might be a result of reduced photosynthetic activity and account for the decreased starch and sucrose levels seen in phd1 leaves. PHD1 overexpression increased photosynthetic efficiency, biomass, and grain production, suggesting that PHD1 plays an important role in supplying sufficient galactolipids to thylakoid membranes for proper chloroplast biogenesis and photosynthetic activity. These findings will be useful for improving crop yields and for bioenergy crop engineering. Photosynthesis is carried out in chloroplast, a plant-specific organelle. Photosynthetic membranes in chloroplasts contain high levels of glycolipids, and UDP-galactose is a dominating donor for glycolipid biosynthesis. Although glycolipid assembly of photosynthetic membranes has been characterized at the genetic and enzymatic level, the mechanism of substrate supply of UDP-galactose for the glycolipid biosynthetic pathway remains obscure. By genetic screening of rice mutants that are impaired in photosynthetic capacity and carbon assimilation, we identified PHD1 as a novel nucleotide sugar epimerase involved in a process of glycolipid biosynthesis and participating in photosynthetic membrane biogenesis. PHD1 was preferentially expressed in green and meristem tissues, and the PHD1 protein was targeted to chloroplasts. We revealed that UDP-galactose for glycolipid biosynthesis catalyzed by the new enzyme was generated inside chloroplasts, and the reduced amounts of glycolipids in the mutant led to decreased chlorophyll content and photosynthetic activity. Overexpression of this gene lead to growth acceleration, enhanced photosynthetic efficiency, and finally improved biomass and grain yield in rice. These results suggest that PHD1 has significant economic implications in both traditional crop improvement and bioenergy crop production.
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Affiliation(s)
- Chunlai Li
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
- Graduate University of the Chinese Academy of Sciences, Beijing, China
| | - Yiqin Wang
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - Linchuan Liu
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
- Graduate University of the Chinese Academy of Sciences, Beijing, China
| | - Yingchun Hu
- College of Life Sciences, Peking University, Beijing, China
| | - Fengxia Zhang
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - Sod Mergen
- College of Life Sciences, Peking University, Beijing, China
| | - Guodong Wang
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - Michael R. Schläppi
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
- Department of Biological Sciences, Marquette University, Milwaukee, Wisconsin, United States of America
| | - Chengcai Chu
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
- * E-mail:
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Hu B, Zhu C, Li F, Tang J, Wang Y, Lin A, Liu L, Che R, Chu C. LEAF TIP NECROSIS1 plays a pivotal role in the regulation of multiple phosphate starvation responses in rice. PLANT PHYSIOLOGY 2011; 156:1101-15. [PMID: 21317339 PMCID: PMC3135962 DOI: 10.1104/pp.110.170209] [Citation(s) in RCA: 142] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2010] [Accepted: 01/24/2011] [Indexed: 05/18/2023]
Abstract
Although phosphate (Pi) starvation signaling is well studied in Arabidopsis (Arabidopsis thaliana), it is still largely unknown in rice (Oryza sativa). In this work, a rice leaf tip necrosis1 (ltn1) mutant was identified and characterized. Map-based cloning identified LTN1 as LOC_Os05g48390, the putative ortholog of Arabidopsis PHO2, which plays important roles in Pi starvation signaling. Analysis of transgenic plants harboring a LTN1 promoter::β-glucuronidase construct revealed that LTN1 was preferentially expressed in vascular tissues. The ltn1 mutant exhibited increased Pi uptake and translocation, which led to Pi overaccumulation in shoots. In association with enhanced Pi uptake and transport, some Pi transporters were up-regulated in the ltn1 mutant in the presence of sufficient Pi. Furthermore, the elongation of primary and adventitious roots was enhanced in the ltn1 mutant under Pi starvation, suggesting that LTN1 is involved in Pi-dependent root architecture alteration. Under Pi-sufficient conditions, typical Pi starvation responses such as stimulation of phosphatase and RNase activities, lipid composition alteration, nitrogen assimilation repression, and increased metal uptake were also activated in ltn1. Moreover, analysis of OsmiR399-overexpressing plants showed that LTN1 was down-regulated by OsmiR399. Our results strongly indicate that LTN1 is a crucial Pi starvation signaling component downstream of miR399 involved in the regulation of multiple Pi starvation responses in rice.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Chengcai Chu
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China (B.H., C.Z., F.L., J.T., Y.W., A.L., L.L., R.C., C.C.); Graduate School of the Chinese Academy of Sciences, Beijing 100049, China (B.H., A.L., L.L., R.C.)
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Tang J, Zhu X, Wang Y, Liu L, Xu B, Li F, Fang J, Chu C. Semi-dominant mutations in the CC-NB-LRR-type R gene, NLS1, lead to constitutive activation of defense responses in rice. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2011; 66:996-1007. [PMID: 21418352 DOI: 10.1111/j.1365-313x.2011.04557.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
In this study, we characterized the semi-dominant mutant nls1-1D (necrotic leaf sheath 1) of rice, which displays spontaneous lesions, specifically on leaf sheaths, with a developmental pattern. nls1-1D plants also exhibited constitutively activated defense responses, including extensive cell death, excess hydrogen peroxide and salicylic acid (SA) accumulation, up-regulated expressions of pathogenesis-related genes, and enhanced resistance to bacterial pathogens. Map-based cloning revealed that NLS1 encodes a typical CC-NB-LRR-type protein in rice. The nls1-1D mutation causes a S367N substitution in the non-conserved region close to the GLPL motif of the NB domain. An adjacent S366T substitution was found in another semi-dominant mutant, nls1-2D, which exhibited the same phenotypes as nls1-1D. Combined analyses of wild-type plants transformed with the mutant NLS1 gene (nls1-1D), NLS1 RNAi and over-expression transgenic lines showed that nls1-2D is allelic to nls1-1D, and both mutations may cause constitutive auto-activation of the NLS1 R protein. Further real-time PCR analysis revealed that NLS1 is expressed constitutively in an age-dependent manner. In addition, because the morphology and constitutive defense responses of nls1-1D were not suppressed by blocking SA or NPR1 transcript accumulation, we suggest that NLS1 mediates both SA and NPR1-independent defense signaling pathways in rice.
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Affiliation(s)
- Jiuyou Tang
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
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Rice DENSE AND ERECT PANICLE 2 is essential for determining panicle outgrowth and elongation. Cell Res 2010; 20:838-49. [PMID: 20502443 DOI: 10.1038/cr.2010.69] [Citation(s) in RCA: 85] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
The architecture of the panicle, including grain size and panicle morphology, directly determines grain yield. Panicle erectness, which is selected for achieving ideal plant architecture in the northern part of China, has drawn increasing attention of rice breeders. Here, dense and erect panicle 2 (dep2) mutant, which shows a dense and erect panicle phenotype, was identified. DEP2 encodes a plant-specific protein without any known functional domain. Expression profiling of DEP2 revealed that it is highly expressed in young tissues, with most abundance in young panicles. Morphological and expression analysis indicated that mutation in DEP2 mainly affects the rapid elongation of rachis and primary and secondary branches, but does not impair the initiation or formation of panicle primordia. Further analysis suggests that decrease of panicle length in dep2 is caused by a defect in cell proliferation during the exponential elongation of panicle. Despite a more compact plant type in the dep2 mutant, no significant alteration in grain production was found between wild type and dep2 mutant. Therefore, the study of DEP2 not only strengthens our understanding of the molecular genetic basis of panicle architecture but also has important implications for rice breeding.
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Jiang SY, Ramachandran S. Natural and artificial mutants as valuable resources for functional genomics and molecular breeding. Int J Biol Sci 2010; 6:228-51. [PMID: 20440406 PMCID: PMC2862397 DOI: 10.7150/ijbs.6.228] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2010] [Accepted: 04/20/2010] [Indexed: 12/31/2022] Open
Abstract
With the completion of rice genome sequencing, large collection of expression data and the great efforts in annotating rice genomes, the next challenge is to systematically assign functions to all predicted genes in the genome. The generations and collections of mutants at the genome-wide level form technological platform of functional genomics. In this study, we have reviewed currently employed tools to generate such mutant populations. These tools include natural, physical, chemical, tissue culture, T-DNA, transposon or gene silencing based mutagenesis. We also reviewed how these tools were used to generate a large collection of mutants and how these mutants can be screened and detected for functional analysis of a gene. The data suggested that the current population of mutants might be large enough to tag all predicted genes. However, the collection of flanking sequencing tags (FSTs) is limited due to the relatively higher cost. Thus, we have proposed a new strategy to generate gene-silencing mutants at the genome-wide level. Due to the large collection of insertion mutants, the next step to rice functional genomics should be focusing on functional characterization of tagged genes by detailed survey of corresponding mutants. Additionally, we also evaluated the utilization of these mutants as valuable resources for molecular breeding.
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Affiliation(s)
| | - Srinivasan Ramachandran
- Rice Functional Genomics Group, Temasek Life Sciences Laboratory, 1 Research Link, Singapore 117604
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