エンドウ トシヤ   ENDO TOSHIYA
  遠藤 斗志也
   所属   京都産業大学  生命科学部 先端生命科学科
   職種   客員教授
言語種別 英語
発行・発表の年月 2019/08
形態種別 研究論文
査読 査読あり
標題 Fertilization-Coupled Sperm Nuclear Fusion is Required for Normal Endosperm Nuclear Proliferation.
執筆形態 その他
掲載誌名 Plant & cell physiology
掲載区分国内
巻・号・頁 61(1),pp.29-40
著者・共著者 Maruyama D,Higashiyama T,Endo T,Nishikawa SI
概要 Angiosperms exhibit double fertilization, a process in which one of the sperm cells released from the pollen tube fertilizes the egg, while the other sperm cell fertilizes the central cell, giving rise to the embryo and endosperm, respectively. We have previously reported two polar nuclear fusion-defective double knockout mutants of Arabidopsis thaliana immunoglobulin binding protein (BiP), a molecular chaperone of the heat shock protein 70 (Hsp70) localized in the endoplasmic reticulum (ER), (bip1 bip2) and its partner ER-resident J-proteins, ERdj3A and P58IPK (erdj3a p58ipk). These mutants are defective in the fusion of outer nuclear membrane and exhibit characteristic seed developmental defects after fertilization with wild-type pollen, which are accompanied by aberrant endosperm nuclear proliferation. In this study, we used time-lapse live-cell imaging analysis to determine the cause of aberrant endosperm nuclear division in these mutant seeds. We found that the central cell of bip1 bip2 or erdj3a p58ipk double mutant female gametophytes was also defective in sperm nuclear fusion at fertilization. Sperm nuclear fusion was achieved after the onset of the first endosperm nuclear division. However, division of the condensed sperm nucleus resulted in aberrant endosperm nuclear divisions and delayed expression of paternally derived genes. By contrast, the other double knockout mutant, erdj3b p58ipk, which is defective in the fusion of inner membrane of polar nuclei but does not show aberrant endosperm nuclear proliferation, was not defective in sperm nuclear fusion at fertilization. We thus propose that premitotic sperm nuclear fusion in the central cell is critical for normal endosperm nuclear proliferation.
DOI 10.1093/pcp/pcz158
ISSN 0032-0781
PMID 31410484