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Expression of Ta CYP 78A3 , a gene encoding cytochrome P450 CYP 78A3 protein in wheat ( Triticum aestivum L.), affects seed size
Author(s) -
Ma Meng,
Wang Qian,
Li Zhanjie,
Cheng Huihui,
Li Zhaojie,
Liu Xiangli,
Song Weining,
Appels Rudi,
Zhao Huixian
Publication year - 2015
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1111/tpj.12896
Subject(s) - biology , ovule , arabidopsis , integument , embryo , gene , gene expression , coat , arabidopsis thaliana , microbiology and biotechnology , botany , genetics , paleontology , mutant
Summary 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 Ta CYP 78A3 gene and its effect on seed size. Ta CYP 78A3 encoded wheat cytochrome P450 CYP 78A3, and was specifically expressed in wheat reproductive organs. Ta CYP 78A3 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 Ta CYP 78A3 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 Ta CYP 78A3 expression level, which affected the extent of integument cell proliferation in the developing ovule and seed. Unfortunately, Ta CYP 78A3 over‐expression in Arabidopsis caused a reduced seed set due to an ovule developmental defect. Moreover, Ta CYP 78A3 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 Ta CYP 78A3 plays critical roles in influencing seed size by affecting the extent of integument cell proliferation. The present study provides direct evidence that Ta CYP 78A3 affects seed size in wheat, and contributes to an understanding of the cellular basis of the gene influencing seed development.