Auxin Transporter OsPIN1b, a Novel Regulator of Leaf Inclination in Rice (<i>Oryza sativa</i> L.)
Yanjun Zhang,
Shaqila Han,
Yuqing Lin,
Jiyue Qiao,
Naren Han,
Yanyan Li,
Yaning Feng,
Dongming Li,
Yanhua Qi
Affiliations
Yanjun Zhang
Key Laboratory of Herbage & Endemic Crop Biology of Ministry of Education, Inner Mongolia Key Laboratory of Herbage & Endemic Crop Biotechnology, School of Life Sciences, Inner Mongolia University, Hohhot 010030, China
Shaqila Han
Key Laboratory of Herbage & Endemic Crop Biology of Ministry of Education, Inner Mongolia Key Laboratory of Herbage & Endemic Crop Biotechnology, School of Life Sciences, Inner Mongolia University, Hohhot 010030, China
Yuqing Lin
State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou 310058, China
Jiyue Qiao
State Key Laboratory of Rice Biology, China National Rice Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou 310006, China
Naren Han
Key Laboratory of Herbage & Endemic Crop Biology of Ministry of Education, Inner Mongolia Key Laboratory of Herbage & Endemic Crop Biotechnology, School of Life Sciences, Inner Mongolia University, Hohhot 010030, China
Yanyan Li
College of Life Science and Technology, Inner Mongolia Normal University, Hohhot 010022, China
Yaning Feng
College of Life Science and Technology, Inner Mongolia Normal University, Hohhot 010022, China
Dongming Li
Key Laboratory of Herbage & Endemic Crop Biology of Ministry of Education, Inner Mongolia Key Laboratory of Herbage & Endemic Crop Biotechnology, School of Life Sciences, Inner Mongolia University, Hohhot 010030, China
Yanhua Qi
Key Laboratory of Herbage & Endemic Crop Biology of Ministry of Education, Inner Mongolia Key Laboratory of Herbage & Endemic Crop Biotechnology, School of Life Sciences, Inner Mongolia University, Hohhot 010030, China
Leaf inclination is one of the most important components of the ideal architecture, which effects yield gain. Leaf inclination was shown that is mainly regulated by brassinosteroid (BR) and auxin signaling. Here, we reveal a novel regulator of leaf inclination, auxin transporter OsPIN1b. Two CRISPR-Cas9 homozygous mutants, ospin1b-1 and ospin1b-2, with smaller leaf inclination compared to the wild-type, Nipponbare (WT/NIP), while overexpression lines, OE-OsPIN1b-1 and OE-OsPIN1b-2 have opposite phenotype. Further cell biological observation showed that in the adaxial region, OE-OsPIN1b-1 has significant bulge compared to WT/NIP and ospin1b-1, indicating that the increase in the adaxial cell division results in the enlarging of the leaf inclination in OE-OsPIN1b-1. The OsPIN1b was localized on the plasma membrane, and the free IAA contents in the lamina joint of ospin1b mutants were significantly increased while they were decreased in OE-OsPIN1b lines, suggesting that OsPIN1b might action an auxin transporter such as AtPIN1 to alter IAA content and leaf inclination. Furthermore, the OsPIN1b expression was induced by exogenous epibrassinolide (24-eBL) and IAA, and ospin1b mutants are insensitive to BR or IAA treatment, indicating that the effecting leaf inclination is regulated by OsPIN1b. This study contributes a new gene resource for molecular design breeding of rice architecture.
