Qin Genji, Ma Zhiqiang, Zhang Li, Xing Shufan, Hou Xianhui, Deng Jie, Liu Jingjing, Chen Zhangliang, Qu Li-Jia, Gu Hongya
National Laboratory for Protein Engineering and Plant Genetic Engineering, Peking-Yale Joint Research Center for Plant Molecular Genetics and AgroBiotechnology, College of Life Sciences, Peking University, Beijing, China.
Cell Res. 2007 Mar;17(3):249-63. doi: 10.1038/cr.2007.7.
Pollen germination on the surface of compatible stigmatic tissues is an essential step for plant fertilization. Here we report that the Arabidopsis mutant bcl1 is male sterile as a result of the failure of pollen germination. We show that the bcl1 mutant allele cannot be transmitted by male gametophytes and no homozygous bcl1 mutants were obtained. Analysis of pollen developmental stages indicates that the bcl1 mutation affects pollen germination but not pollen maturation. Molecular analysis demonstrates that the failure of pollen germination was caused by the disruption of AtBECLIN 1. AtBECLIN 1 is expressed predominantly in mature pollen and encodes a protein with significant homology to Beclin1/Atg6/Vps30 required for the processes of autophagy and vacuolar protein sorting (VPS) in yeast. We also show that AtBECLIN 1 is required for normal plant development, and that genes related to autophagy, VPS and the glycosylphosphatidylinositol anchor system, were affected by the deficiency of AtBECLIN 1.
花粉在亲和性柱头组织表面萌发是植物受精的关键步骤。在此，我们报道拟南芥突变体bcl1由于花粉萌发失败而表现为雄性不育。我们发现bcl1突变等位基因不能通过雄配子体传递，且未获得纯合的bcl1突变体。对花粉发育阶段的分析表明，bcl1突变影响花粉萌发，但不影响花粉成熟。分子分析显示，花粉萌发失败是由AtBECLIN 1的破坏所致。AtBECLIN 1主要在成熟花粉中表达，编码一种与酵母自噬和液泡蛋白分选（VPS）过程所需的Beclin1/Atg6/Vps30具有显著同源性的蛋白质。我们还表明，AtBECLIN 1是正常植物发育所必需的，并且与自噬、VPS和糖基磷脂酰肌醇锚定系统相关的基因受到AtBECLIN 1缺乏的影响。
