TY - JOUR
T1 - Role of brassinosteroids in rice spikelet differentiation and degeneration under soil-drying during panicle development
AU - Zhang, Weiyang
AU - Sheng, Jiayan
AU - Xu, Yunji
AU - Xiong, Fei
AU - Wu, Yunfei
AU - Wang, Weilu
AU - Wang, Zhiqin
AU - Yang, Jianchang
AU - Zhang, Jianhua
N1 - Funding Information:
This study was financially supported by the grants from the National Natural Science Foundation of China (31461143015, 31771710), the National Key Research and Development Program of China (2016YFD0300206–4, 2018YFD0300801), the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD), the Top Talent Supporting Program of Yangzhou University (2015–01), the Council of Hong Kong Baptist University (1806439), the Project funded by China Postdoctoral Science Foundation (2018 M640528), and the Open Project from Joint International Research Laboratory of Agriculture and Agri-Product Safety of Yangzhou University (JRK2018004).
PY - 2019/9/18
Y1 - 2019/9/18
N2 - Background: Brassinosteroids (BRs) are a new group of plant hormones and play important roles in plant growth and development. However, little information is available if BRs could regulate spikelet development in rice (Oryza sativa L.) especially under soil-drying conditions. This study investigated whether and how BRs mediate the effect of soil-drying on spikelet differentiation and degeneration in rice. A rice cultivar was field-grown and exposed to three soil moisture treatments during panicle development, that is, well-watered (WW), moderate soil-drying (MD) and severe soil-drying (SD). Results: Compared with the WW treatment, the MD treatment enhanced BRs biosynthesis in young panicles, increased spikelet differentiation and reduced spikelet degeneration. The SD treatment had the opposite effects. Changes in expression levels of key rice inflorescence development genes (OsAPO2 and OsTAW1), ascorbic acid (AsA) content, and activities of enzymes involved AsA synthesis and recycle, and amount of nonstructural carbohydrates (NSC) in young panicles were consistent with those in BRs levels, whereas hydrogen peroxide (H2O2) content showed opposite trend. Knockdown of the BRs synthesis gene OsD11 or application of a BRs biosynthesis inhibitor to young panicles markedly decreased OsAPO2 and OsTAW1 expression levels, BRs and AsA contents, activities of enzymes involved AsA synthesis and recycle, NSC amount in rice panicles and spikelet differentiation but increased the H2O2 content and spikelet degeneration compared to the control (the wide type or application of water). The opposite effects were observed when exogenous BRs were applied. Conclusions: The results suggest that BRs mediate the effect of soil-drying on spikelet differentiation and degeneration, and elevated BRs levels in rice panicles promote spikelet development under MD by enhancing inflorescence meristem activity, AsA recycle and NSC partitioning to the growing panicles.
AB - Background: Brassinosteroids (BRs) are a new group of plant hormones and play important roles in plant growth and development. However, little information is available if BRs could regulate spikelet development in rice (Oryza sativa L.) especially under soil-drying conditions. This study investigated whether and how BRs mediate the effect of soil-drying on spikelet differentiation and degeneration in rice. A rice cultivar was field-grown and exposed to three soil moisture treatments during panicle development, that is, well-watered (WW), moderate soil-drying (MD) and severe soil-drying (SD). Results: Compared with the WW treatment, the MD treatment enhanced BRs biosynthesis in young panicles, increased spikelet differentiation and reduced spikelet degeneration. The SD treatment had the opposite effects. Changes in expression levels of key rice inflorescence development genes (OsAPO2 and OsTAW1), ascorbic acid (AsA) content, and activities of enzymes involved AsA synthesis and recycle, and amount of nonstructural carbohydrates (NSC) in young panicles were consistent with those in BRs levels, whereas hydrogen peroxide (H2O2) content showed opposite trend. Knockdown of the BRs synthesis gene OsD11 or application of a BRs biosynthesis inhibitor to young panicles markedly decreased OsAPO2 and OsTAW1 expression levels, BRs and AsA contents, activities of enzymes involved AsA synthesis and recycle, NSC amount in rice panicles and spikelet differentiation but increased the H2O2 content and spikelet degeneration compared to the control (the wide type or application of water). The opposite effects were observed when exogenous BRs were applied. Conclusions: The results suggest that BRs mediate the effect of soil-drying on spikelet differentiation and degeneration, and elevated BRs levels in rice panicles promote spikelet development under MD by enhancing inflorescence meristem activity, AsA recycle and NSC partitioning to the growing panicles.
KW - Ascorbic acid (AsA)
KW - Assimilate distribution
KW - Brassinosteroids (BRs)
KW - Rice (Oryza sativa L.)
KW - Soil-drying
KW - Spikelet differentiation and degeneration
UR - http://www.scopus.com/inward/record.url?scp=85072370154&partnerID=8YFLogxK
U2 - 10.1186/s12870-019-2025-2
DO - 10.1186/s12870-019-2025-2
M3 - Journal article
C2 - 31533628
AN - SCOPUS:85072370154
SN - 1471-2229
VL - 19
JO - BMC Plant Biology
JF - BMC Plant Biology
IS - 1
M1 - 409
ER -