title: Expression of TaCYP78A3, a gene encoding cytochrome P450 CYP78A3 protein in wheat (Triticum aestivum L.), affects seed size.
abstract: 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 TaCYP78A3 gene and its effect on seed size. TaCYP78A3 encoded wheat cytochrome P450 CYP78A3, and was specifically expressed in wheat reproductive organs. TaCYP78A3 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 TaCYP78A3 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 TaCYP78A3 expression level, which affected the extent of integument cell proliferation in the developing ovule and seed. Unfortunately, TaCYP78A3 over-expression in Arabidopsis caused a reduced seed set due to an ovule developmental defect. Moreover, TaCYP78A3 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 TaCYP78A3 plays critical roles in influencing seed size by affecting the extent of integument cell proliferation. The present study provides direct evidence that TaCYP78A3 affects seed size in wheat, and contributes to an understanding of the cellular basis of the gene influencing seed development.
authors.affiliation: College of Life Sciences, Northwest A & F University, Yangling, Shaanxi, 712100, China.
authors.forename: Meng
authors.initials: M
authors.lastname: Ma
authors.affiliation: College of Life Sciences, Northwest A & F University, Yangling, Shaanxi, 712100, China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Wang
authors.affiliation: College of Life Sciences, Northwest A & F University, Yangling, Shaanxi, 712100, China.
authors.forename: Zhanjie
authors.initials: Z
authors.lastname: Li
authors.affiliation: College of Life Sciences, Northwest A & F University, Yangling, Shaanxi, 712100, China.
authors.forename: Huihui
authors.initials: H
authors.lastname: Cheng
authors.affiliation: College of Life Sciences, Northwest A & F University, Yangling, Shaanxi, 712100, China.
authors.forename: Zhaojie
authors.initials: Z
authors.lastname: Li
authors.affiliation: College of Life Sciences, Northwest A & F University, Yangling, Shaanxi, 712100, China.
authors.forename: Xiangli
authors.initials: X
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Crop Stress Biology in Arid Areas, Northwest A & F University, Yangling, Shaanxi, 712100, China.|College of Agronomy, Northwest A & F University, Yangling, Shaanxi, 712100, China.
authors.forename: Weining
authors.initials: W
authors.lastname: Song
authors.affiliation: School of Veterinary and Life Sciences, Murdoch University, South Street, Murdoch, WA, 6150, Australia.
authors.forename: Rudi
authors.initials: R
authors.lastname: Appels
authors.affiliation: College of Life Sciences, Northwest A & F University, Yangling, Shaanxi, 712100, China.|State Key Laboratory of Crop Stress Biology in Arid Areas, Northwest A & F University, Yangling, Shaanxi, 712100, China.
authors.forename: Huixian
authors.initials: H
authors.lastname: Zhao
mesh_terms: D049109:Cell Proliferation / Q000235:genetics; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics*; D015971:Gene Expression Regulation, Enzymologic; D018506:Gene Expression Regulation, Plant; D020868:Gene Silencing; D017343:Genes, Plant; D008969:Molecular Sequence Data; D010802:Phylogeny; D040641:Quantitative Trait Loci; D012639:Seeds; D014908:Triticum / Q000196:embryology / Q000201:enzymology* / Q000235:genetics
chemical_list: D003577:Cytochrome P-450 Enzyme System
keywords: BSMV-VIGS; CYP78A; TaCYP78A3; Triticum aestivum; cytochrome P450; seed size