The Arabidopsis transcription factor IIB-related protein BRP4 is involved in the regulation of mitotic cell-cycle progression during male gametogenesis.
Male gametogenesis in angiosperms involves two rounds of mitosis that are essential for the generation of two sperm cells to achieve double fertilization, a distinct event in the sexual reproduction of flowering plants. Precise regulation of mitosis during male gametogenesis is critically important for the establishment of the male germline. However, the molecular mechanisms underlying mitotic division during male gametophyte development have not been characterized fully. Here, we report that the Arabidopsis transcription initiation factor TFIIB-related protein BRP4 is involved in the regulation of mitotic cell-cycle progression during male gametogenesis. BRP4 was expressed predominately in developing male gametophytes. Knockdown expression of BRP4 by a native promoter-driven RNA interference construct in Arabidopsis resulted in arrest of the mitotic progression of male gametophytes, leading to a defect in pollen development. Moreover, we showed that the level of expression of a gene encoding a subunit of the origin recognition complex, ORC6, was decreased in BRP4 knockdown plants, and that the ORC6 knockdown transgenic plants phenocopied the male gametophyte defect observed in BRP4 knockdown plants, suggesting that ORC6 acts downstream of BRP4 to mediate male mitotic progression. Taken together, our results reveal that BRP4 plays an important role in the regulation of mitotic cell-cycle progression during male gametogenesis.
Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, PR China.
Zhixiang
Z
Qin
Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, PR China University of Chinese Academy of Sciences, Beijing, PR China.
Xiaoran
X
Zhang
Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, PR China University of Chinese Academy of Sciences, Beijing, PR China.
Xiao
X
Zhang
Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, PR China.
Wei
W
Xin
Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, PR China.
Jia
J
Li
Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, PR China National Center for Plant Gene Research, Beijing, PR China huyuxin@ibcas.ac.cn.
Yuxin
Y
Hu
D017360:Arabidopsis / Q000166:cytology* / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D056130:Gametogenesis, Plant; D018506:Gene Expression Regulation, Plant; D008938:Mitosis; D051738:Origin Recognition Complex / Q000235:genetics / Q000378:metabolism; D011058:Pollen / Q000166:cytology* / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors; D019473:Transcription Factors, TFII / Q000235:genetics / Q000378:metabolism*
D029681:Arabidopsis Proteins; C000594293:BRP4 protein, Arabidopsis; D051738:Origin Recognition Complex; D014157:Transcription Factors; D019473:Transcription Factors, TFII; C474201:transcription factor IIB-related protein, Arabidopsis
Arabidopsis; BRP4; ORC6; TFIIB-related protein.; male gametogenesis; mitosis