title: TaCYP78A5 regulates seed size in wheat (Triticum aestivum).
abstract: Seed size is an important agronomic trait and a major component of seed yield in wheat. However, little is known about the genes and mechanisms that determine the final seed size in wheat. Here, we isolated TaCYP78A5, the orthologous gene of Arabidopsis CYP78A5/KLUH in wheat, from wheat cv. Shaan 512 and demonstrated that the expression of TaCYP78A5 affects seed size. TaCYP78A5 encodes the cytochrome P450 (CYP) 78A5 protein in wheat and rescued the phenotype of the Arabidopsis deletion mutant cyp78a5. By affecting the extent of integument cell proliferation in the developing ovule and seed, TaCYP78A5 influenced the growth of the seed coat, which appears to limit seed growth. TaCYP78A5 silencing caused a 10% reduction in cell numbers in the seed coat, resulting in a 10% reduction in seed size in wheat cv. Shaan 512. By contrast, the overexpression of TaCYP78A5 increased the number of cells in the seed coat, resulting in seed enlargement of ~11-35% in Arabidopsis. TaCYP78A5 activity was positively correlated with the final seed size. However, TaCYP78A5 overexpression significantly reduced seed set in Arabidopsis, possibly due to an ovule development defect. TaCYP78A5 also influenced embryo development by promoting embryo integument cell proliferation during seed development. Accordingly, a working model of the influence of TaCYP7A5 on seed size was proposed. This study provides direct evidence that TaCYP78A5 affects seed size and is a potential target for crop improvement.
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 State Key Laboratory of Crop Stress Biology in Arid Areas, Northwest A & F University, Yangling, Shaanxi 712100, China hxzhao212@nwsuaf.edu.cn liuxianglii@163.com.
authors.forename: Huixian
authors.initials: H
authors.lastname: Zhao
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: 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: Shengwu
authors.initials: S
authors.lastname: Hu
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: College of Life Sciences, Northwest A & F University, Yangling, Shaanxi 712100, China hxzhao212@nwsuaf.edu.cn liuxianglii@163.com.
authors.forename: Xiangli
authors.initials: X
authors.lastname: Liu
mesh_terms: D017360:Arabidopsis / Q000166:cytology; D002452:Cell Count; D049109:Cell Proliferation; D017353:Gene Deletion; D020868:Gene Silencing; D008954:Models, Biological; D009154:Mutation / Q000235:genetics; D009929:Organ Size; D056771:Ovule / Q000166:cytology / Q000378:metabolism; D010641:Phenotype; D010802:Phylogeny; D010940:Plant Proteins / Q000378:metabolism*; D012639:Seeds / Q000033:anatomy & histology* / Q000166:cytology; D014908:Triticum / Q000033:anatomy & histology* / Q000166:cytology / Q000196:embryology / Q000254:growth & development
chemical_list: D010940:Plant Proteins
keywords: BSMV-VIGS; CYP78A; TaCYP78A5.; Triticum aestivum L.; cell proliferation; seed size