Expression of TaCYP78A3, a gene encoding cytochrome P450 CYP78A3 protein in wheat (Triticum aestivum L.), affects seed size. (July 2015)

• Record Type: Journal Article
• Authors: Ma, Meng; Wang, Qian; Li, Zhanjie; Cheng, Huihui; Li, Zhaojie; Liu, Xiangli; Song, Weining; Appels, Rudi; Zhao, Huixian
• Is Part Of: Plant journal. Volume 83:Number 2(2015:Jul.)
• Page Start: 312
• Page End: 325
• Publication Date: 2015-07
• Subjects: Plant molecular biology -- Periodicals; Plant cells and tissues -- Periodicals; Botany -- Periodicals; 580
• DOI: 10.1111/tpj.12896
• Languages: English
• ISSNs: 0960-7412

Abstract

<abstract abstract-type="main" id="tpj12896-abs-0001"> <title>Summary</title> <p>Several studies have described quantitative trait loci (QTL) for seed size in wheat, but the relevant genes and molecular mechanisms remain largely unknown. Here we report the functional characterization of the wheat <italic>TaCYP78A3</italic> gene and its effect on seed size. <italic>TaCYP78A3</italic> encoded wheat cytochrome P450 CYP78A3, and was specifically expressed in wheat reproductive organs. <italic>TaCYP78A3</italic> activity was positively correlated with the final seed size. Its silencing caused a reduction of cell number in the seed coat, resulting in an 11% decrease in wheat seed size, whereas <italic>TaCYP78A3</italic> over‐expression induced production of more cells in the seed coat, leading to an 11–48% increase in Arabidopsis seed size. In addition, the cell number in the final seed coat was determined by the <italic>TaCYP78A3</italic> expression level, which affected the extent of integument cell proliferation in the developing ovule and seed. Unfortunately, <italic>TaCYP78A3</italic> over‐expression in Arabidopsis caused a reduced seed set due to an ovule developmental defect. Moreover, <italic>TaCYP78A3</italic> over‐expression affected embryo development by promoting embryo integument cell proliferation during seed development, which also ultimately affected the final seed size in Arabidopsis. In summary, our results indicated that <italic>TaCYP78A3</italic> plays critical roles in influencing seed size by affecting the extent of integument cell proliferation. The present study provides direct evidence that <italic>TaCYP78A3</italic> affects seed size in wheat, and contributes to an understanding of the cellular basis of the gene influencing seed development.</p> </abstract>