Abstract
Yeast ATG6, isolated as an autophagy-related gene, is allelic to VPS30, a component of phosphatidylinositol 3-kinase (PI3K) complex. Screening of T-DNA insertion mutants of Arabidopsis ATG6 has identified no homozygous mutant lines. Approximately 50% of the seeds in the progeny of selfed-heterozygous plant were heterozygous, characteristic of a male gametophytic mutant phenotype. This idea was confirmed by crossing experiments between AtATG6 heterozygous and wild type plants. DAPI staining of mature pollen grains from AtATG6 heterozygous plants detected no phenotypically aberrant pollen. However, efficiency of pollen germination in AtATG6 heterozygous plants seemed to be reduced compared to wild type. When AtATG6 heterozygous plants were crossed to quartet1 mutant, normal and aborted pollen grains from ATG6/atg6/qrt/qrt plants seemed to segregate 2:2 in the tetrads: less than 2 pollen grains in each quartet germinated. These results suggested that ATG6/VPS30 plays critical roles in pollen development.
