Important progress in rice gluten research of Nanjing Agricultural University

The research group of Professor Wan Jianmin of Nanjing Agricultural University has made important progress in the mechanism of rice gluten separation Recently, the plant cell, a famous international authoritative botanical journal, published relevant research results entitled "glutelin precision accumation3 encodes a regulator of post Golgi vascular traffic essential for vacuum protein sorting in rice endosperm" Dr Ren Yulong, Associate Professor Wang Yihua and Dr Liu Feng are the first authors of this paper, and Professor Wan Jianmin is the corresponding author Rice contains a lot of storage protein, which is the second largest substance in rice after starch Among them, gluten is the highest storage protein in rice seeds, accounting for more than 70% of the total protein in the seeds It plays an important role in the quality and nutritional value of rice Glutelin was first synthesized in endoplasmic reticulum of endosperm cells in the form of 57kda precursor, and then transported to protein storage vacuole (PSV) through complex vesicle transport process After further processing, it finally gathered to form type II protein body (PBII) However, little is known about the vesicle transport process and the molecular mechanism of directional separation of Glutenin precursors A series of mutants with abnormal accumulation of glutelin precursor were obtained through a large number of screening by researchers of Wan Jianmin research group, one of which was named glutelin precursor accumulation 3 (gpa3) Cytological studies showed that DV (dense vesicle) from Golgi precursor was mistakenly sorted near the cytoplasmic membrane, and the molecules such as glutenin were sorted into extracellular space by membrane fusion, forming a PMB, The abnormal structure of paramural body) showed that gpa3 was a post Golgi sorting defect mutant of rice glutenin, and map cloning revealed that gpa3 gene encoded a plant specific protein containing kelch repeat motif, named oskelch1; In the following functional studies, gpa3 / kelch1 protein can form a functional protein complex with the small G protein gpa1 / RAB5A reported by our group and its upstream activator Gpa2 / vps9a, which can coordinate the directional transport of DV to PSV.