Working group session:
Functional Genomics
Presentation type:
oral
Authors:
Shang, Xiaoguang; Guo, Wangzhen; Ruan, Yong-Ling
Presenter:
Shang, Xiaoguang
Correspondent:
Guo, Wangzhen; Ruan, Yong-Ling
Abstract:
KORRIGAN1 (KOR1) is a membrane-bound endoglucanase that has been implicated in cell wall formation, largely based on studies in vegetative tissues. Its potential role in reproductive development, however, remains unknown. Here, we demonstrated that GhKOR1 played significant roles in cotton (Gossypium hirsutum) endosperm and embryo development and the establishment of early seedling vigor. Down-regulation of GhKOR1 transcript in RNAi or co-suppressed transgenic cotton resulted in smaller filial tissue and reduced seed weight. Further histological studies revealed that silencing KOR1 disrupted endosperm cellularization and delayed embryo development, leading to weak growth of seedling following germination. The transgenic plants exhibited fewer and smaller endosperm cell with irregular brittle cell walls at 10 days post anthesis (DPA) when the wild type endosperm has become highly cellularized. In contrast to the progression to heart stage of the wild type embryo, the transgenic embryo was still in the globular stage at 10 DPA. The transgenic seed also displayed reduced fiber growth. These findings demonstrate that GhKOR1 is required for cytokinesis of endosperm cell and the development of embryo and fiber. Also noteworthy is that down-regulation of GhKOR1 transcript dramatically reduced callose deposition in the seed coat transfer cells. This, however, does not appear to affect the morphology of the transfer cells. Together, the study provides several novel findings which significantly advances our understanding on the functions of KOR1 gene in seed development.