Vacuolar invertase genes SbVIN1 and SbVIN2 are differently associated with stem and grain traits in sorghum (Sorghum bicolor)  

作　　者：Yunhua Chi Kimani Wilson Zhiquan Liu Xiaoyuan Wu Li Shang Limin Zhang Haichun Jing Huaiqing Hao 

机构地区：[1]Key Laboratory of Plant Resources,Institute of Botany,Chinese Academy of Sciences,Beijing 100093,China [2]University of Chinese Academy of Sciences,Beijing 100049,China [3]Engineering Laboratory for Grass-based Livestock Husbandry,Chinese Academy of Sciences,Beijing 100093,China

出　　处：《The Crop Journal》2020年第2期299-312,共14页作物学报（英文版）

基　　金：the National Natural Science Foundation of China(No.31471570,No.31461143023);Ministry of Science and Technology of the People's Republic of China(2015BAD15B03).

摘　　要：In higher plants, vacuolar invertases play essential roles in sugar metabolism, organ development, and sink strength. In sorghum(Sorghum bicolor), two vacuolar invertase genes,Sb VIN1(Sobic. 004 G004800) and Sb VIN2(Sobic. 006 G160700) have been reported, but their enzymatic properties and functional differences are largely unknown. We combined molecular, biochemical and genomic approaches to investigate their roles in sorghum stem and grain traits. Sb VIN1 and Sb VIN2 showed different expression levels in internodes,leaves, and panicles, indicating that their importance in each organ was different. In an in vitro sucrose hydrolysis assay, proteins of both genes heterologously expressed in Pichia pastoris displayed similar enzyme properties including the same optimum reaction p H(5)and similar Kmfor sucroe(49 mmol L-1 and 45 mmol L-1 for Sb VIN1 and Sb VIN2,respectively). The optimum reaction temperatures of Sb VIN1 and Sb VIN2 were 45 °C and65 °C, respectively. Sb VIN2 showed higher tolerance to high temperature than Sb VIN1. We characterized the sequence variation of these two vacuolar invertase genes in a panel of 216 diverse inbred lines of sweet and grain sorghum and performed gene-based association analysis. Sb VIN1 showed significant associations with stem traits including stem length,stem diameter, internode number, stem fresh weight, and Brix, as well as grain traits including hundred-grain weight and grain width. Significantly associated variation sites were mainly in 5′ upstream and intron regions. Sb VIN2 only associated with grain width and stem water-soluble carbohydrates(WSCs) content. We conclude that the vacuolar invertase genes Sb VIN1 and Sb VIN2 are differently associated with stem and grain traits in sorghum.

关 键 词：Sorghum(Sorghum bicolor) VACUOLAR INVERTASE SbVIN1 SbVIN2 ENZYMATIC properties Association analysis 

分 类 号：S514[农业科学—作物学]