1. ¹National 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 100871, China
2. ²The National Plant Gene Research Center (Beijing), Beijing 100101, China

Correspondence: Hongya Gu, Fax: +86-10-6275-1841 E-mail: guhy@pku.edu.cn

Received 31 December 2006; Revised 23 January 2007; Accepted 2 February 2007.

Abstract

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.