Plastidic pyruvate dehydrogenase complex E1 component subunit Alpha1 is involved in galactolipid biosynthesis required for amyloplast development in rice

• DOI: 10.1111/pbi.13727
• Publication Date: 2021-10-20T21:24:50Z
• Authors: Jie Lei; Xuan Teng; Yongfei Wang; Xiaokang Jiang; Huanhuan Zhao; Xiaoming Zheng; Yulong Ren; Hui Dong; Yunlong Wang; Erchao Duan; Yuanyan Zhang; Wenwei Zhang; Hang Yang; Xiaoli Chen; Rongbo Chen; Yu Zhang; Mingzhou Yu; Shanbin Xu; Xiuhao Bao; Pengcheng Zhang; Shijia Liu; Xi Liu; Yunlu Tian; Ling Jiang; Yihua Wang; Jianmin Wan
• Keywords: Amyloplast

Starch accounts for over 80% of the total dry weight in cereal endosperm and determines kernel texture nutritional quality. Amyloplasts, terminally differentiated plastids, are responsible starch biosynthesis storage. We screened a series rice mutants with floury to clarify mechanism underlying amyloplast development synthesis. identified endosperm19 (flo19) mutant which shows opaque interior endosperm. Abnormal compound grains (SGs) were present cells mutant. Molecular cloning revealed that FLO19 allele encodes plastid-localized pyruvate dehydrogenase complex E1 component subunit α1 (ptPDC-E1-α1) is expressed all tissues. In vivo enzyme assays demonstrated flo19 showed decreased activity plastidic complex. addition, amounts monogalactosyldiacylglycerol (MGDG) digalactosyldiacylglycerol (DGDG) much lower developing endosperm, suggesting participates fatty acid supply galactolipid amyloplasts. overexpression significantly increased seed size weight, but did not affect other important agronomic traits, such as panicle length, tiller number setting rate. An analysis single nucleotide polymorphism data from panel accessions pFLO19L haplotype was positively associated grain implying potential application breeding. summary, our study demonstrates involved essential rice.