The DC1 domain protein Vacuoleless Gametophytes regulates stamen development in Arabidopsis

Abstract

Vacuoleless Gametophytes (VLG) is a DC1 domain protein that was initially characterized as essential for early female and male gametophytes development in Arabidopsis. However, VLG expression was also detected in stamens, pistils and other sporophytic tissues, implying a broader role for this protein. As homozygous insertional VLG lines resulted unviable, we generated Arabidopsis amiRNA VLG knock-down plants to study the role of VLG in sporophyte development. The phenotypic characterization of VLG knock-down plants showed reduced seed set and indehiscent anthers with shorter filaments and stigma exsertion. Moreover, amiRNA VLG knock-down plants displayed unbroken stomia and septa, markedly reduced endothecium lignification, diminished ROS accumulation, and lower transcript levels of genes involved in jasmonic acid and lignin biosynthesis. The indehiscent phenotype was rescued by exogenous application of either jasmonic acid or H2O2. Altogether, our results suggest that VLG is involved in lignin and jasmonic acid biosynthesis pathways, and that proper levels of VLG are required in the process that leads to stomium breakage and anther dehiscence. Our findings shed light on the mechanisms underlying stamen development and provide new insights into the roles of a DC1 domain protein in plant reproduction.