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Arabidopsis replication factor C4 is critical for DNA replication during the mitotic cell cycle
Author(s) -
Qian Jie,
Chen Yueyue,
Hu Ying,
Deng Yingtian,
Liu Yang,
Li Gang,
Zou Wenxuan,
Zhao Jie
Publication year - 2018
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.13855
Subject(s) - biology , endosperm , zygote , microbiology and biotechnology , suspensor , dna replication , embryo , mitosis , control of chromosome duplication , cell cycle , dna replication factor cdt1 , arabidopsis , licensing factor , genetics , dna , gene , embryogenesis , mutant
Summary Replication factor C ( RFC ) is a conserved eukaryotic complex consisting of RFC 1/2/3/4/5. It plays important roles in DNA replication and the cell cycle in yeast and fruit fly. However, it is not very clear how RFC subunits function in higher plants, except for the Arabidopsis ( At ) subunits At RFC 1 and At RFC 3 . In this study, we investigated the functions of At RFC 4 and found that loss of function of At RFC 4 led to an early sporophyte lethality that initiated as early as the elongated zygote stage, all defective embryos arrested at the two‐ to four‐cell embryo proper stage, and the endosperm possessed six to eight free nuclei. Complementation of rfc4‐1 /+ with At RFC 4 expression driven through the embryo‐specific DD 45pro and ABI 3pro or the endosperm‐specific FIS 2pro could not completely restore the defective embryo or endosperm, whereas a combination of these three promoters in rfc4‐1 /+ enabled the aborted ovules to develop into viable seeds. This suggests that At RFC 4 functions simultaneously in endosperm and embryo and that the proliferation of endosperm is critical for embryo maturation. Assays of DNA content in rfc4‐1 /+ verified that DNA replication was disrupted in endosperm and embryo, resulting in blocked mitosis. Moreover, we observed a decreased proportion of late S‐phase and M‐phase cells in the rfc4‐1 /– FIS 2; DD 45; ABI 3pro::At RFC 4 seedlings, suggesting that incomplete DNA replication triggered cell cycle arrest in cells of the root apical meristem. Therefore, we conclude that At RFC 4 is a crucial gene for DNA replication.