Cargando…

A CYP78As–small grain4–coat protein complex Ⅱ pathway promotes grain size in rice

CYP78A, a cytochrome P450 subfamily that includes rice (Oryza sativa L.) BIG GRAIN2 (BG2, CYP78A13) and Arabidopsis thaliana KLUH (KLU, CYP78A5), generate an unknown mobile growth signal (referred to as a CYP78A-derived signal) that increases grain (seed) size. However, the mechanism by which the CY...

Descripción completa

Detalles Bibliográficos
Autores principales: Zhou, Chunlei, Lin, Qibing, Ren, Yulong, Lan, Jie, Miao, Rong, Feng, Miao, Wang, Xin, Liu, Xi, Zhang, Shengzhong, Pan, Tian, Wang, Jiachang, Luo, Sheng, Qian, Jinsheng, Luo, Wenfan, Mou, Changling, Nguyen, Thanhliem, Cheng, Zhijun, Zhang, Xin, Lei, Cailin, Zhu, Shanshan, Guo, Xiuping, Wang, Jie, Zhao, Zhichao, Liu, Shijia, Jiang, Ling, Wan, Jianmin
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Oxford University Press 2023
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10689148/
https://www.ncbi.nlm.nih.gov/pubmed/37738653
http://dx.doi.org/10.1093/plcell/koad239
Descripción
Sumario:CYP78A, a cytochrome P450 subfamily that includes rice (Oryza sativa L.) BIG GRAIN2 (BG2, CYP78A13) and Arabidopsis thaliana KLUH (KLU, CYP78A5), generate an unknown mobile growth signal (referred to as a CYP78A-derived signal) that increases grain (seed) size. However, the mechanism by which the CYP78A pathway increases grain size remains elusive. Here, we characterized a rice small grain mutant, small grain4 (smg4), with smaller grains than its wild type due to restricted cell expansion and cell proliferation in spikelet hulls. SMG4 encodes a multidrug and toxic compound extrusion (MATE) transporter. Loss of function of SMG4 causes smaller grains while overexpressing SMG4 results in larger grains. SMG4 is mainly localized to endoplasmic reticulum (ER) exit sites (ERESs) and partially localized to the ER and Golgi. Biochemically, SMG4 interacts with coat protein complex Ⅱ (COPⅡ) components (Sar1, Sec23, and Sec24) and CYP78As (BG2, GRAIN LENGTH 3.2 [GL3.2], and BG2-LIKE 1 [BG2L1]). Genetically, SMG4 acts, at least in part, in a common pathway with Sar1 and CYP78As to regulate grain size. In summary, our findings reveal a CYP78As–SMG4–COPⅡ regulatory pathway for grain size in rice, thus providing new insights into the molecular and genetic regulatory mechanism of grain size.