The small auxin-up RNA OsSAUR45 affects auxin synthesis and transport in rice.
This research is the first to demonstrate that OsSAUR45 is involved in plant growth though affecting auxin synthesis and transport by repressing OsYUCCA and OsPIN gene expression in rice. Small auxin-up RNAs (SAURs) comprise a large multigene family and are rapidly activated as part of the primary auxin response in plants. However, little is known about the role of SAURs in plant growth and development, especially in monocots. Here, we report the biological function of OsSAUR45 in the model plant rice (Oryza sativa). OsSAUR45 is expressed in a tissue-specific pattern and is localized to the cytoplasm. Rice lines overexpressing OsSAUR45 displayed pleiotropic developmental defects including reduced plant height and primary root length, fewer adventitious roots, narrower leaves, and reduced seed setting. Auxin levels and transport were reduced in the OsSAUR45 overexpression lines, potentially because of decreased expression of Flavin-binding monooxygenase family proteins (OsYUCCAs) and PIN-FORMED family proteins (OsPINs). Exogenous auxin application rapidly induced OsSAUR45 expression and partially restored the phenotype of rice lines overexpressing OsSAUR45. These results demonstrate that OsSAUR45 is involved in plant growth by affecting auxin synthesis and transport through the repression of OsYUCCA and OsPIN gene expression in rice.
National Center for Tea Improvement, Tea Research Institute of the Chinese Academy of Agricultural Sciences/Key Laboratory of Tea Biology and Resources Utilization, Ministry of Agriculture, 9 South Meiling Road, Hangzhou, 310008, China. xuyanxia@tricaas.com.|State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou, 310058, China. xuyanxia@tricaas.com.
Yan-Xia
YX
Xu
State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou, 310058, China.
Meng-Zhu
MZ
Xiao
State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou, 310058, China.
Yan
Y
Liu
State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou, 310058, China.
Jun-Liang
JL
Fu
State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou, 310058, China.
Yi
Y
He
State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou, 310058, China. dajiang@zju.edu.cn.
De-An
DA
Jiang
D001692:Biological Transport; D018506:Gene Expression Regulation, Plant / Q000502:physiology*; D007210:Indoleacetic Acids / Q000378:metabolism*; D012275:Oryza / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified; D018749:RNA, Plant / Q000235:genetics / Q000378:metabolism*
D007210:Indoleacetic Acids; D018749:RNA, Plant
Auxin; Gene expression; Oryza sativa (L.); Regulation; SAUR; Synthesis and transport