THE DC1-DOMAIN PROTEIN VLG IS INVOLVED IN ARABIDOPSIS FERTILITY

FRIK, J.; ARIAS, L.; LOMBARDO, M; D IPPÓLITO, SEBASTIAN; TERRILE MC; CASALONGUE, C.; FIOL, D

Salta

Congreso; SAIB PABMB 2019; 2019

SAIB

VACUOLELESS GAMETOPHYTES (VLG) is a DC1 domain containing protein that was first characterized in our laboratory as a necessary factor to complete female and male gametophytes development in Arabidopsis. Its subcellular localization at the prevacuolar compartment and the ability to interact with SNARE proteins suggest a role in the vesicular fusion during vacuolar formation. Vlg expression was also detected in the vasculature, the filament of mature flowers and root elongation zones, implying a broader role for this protein in sporophyte tissues. Since vlg homozygous insertional mutants are lethal, we generated transgenic silenced lines encoding an artificial microRNA targeting vlg transcripts with the aim to explore the loss of VLG function. The phenotypic characterization showed a lower yield in quantity of fruits and number of seeds per fruit in vlg silenced plants as a result of deficient pollination. This phenotype was caused partially by undehisced anthers suggesting reduced male fertility. In addition, the first flowers on the main stem displayed excessive gynoecium elongation which resulted in stigma exsertion and thus impaired pollen-stigma interactions. Rosette leaves were also more elongated in silenced plants and the number of lateral roots was higher, suggesting that VLG may mediate processes that regulate organ morphology. We found that vlg promoter activity is modulated by the hormones auxin and jasmonic acid, both involved in another development and further crossed vlg silenced plants with auxin signaling reporter lines to explore alterations due to diminished VLG levels. Taken together, our results show that VLG participates in the processes mediating fertility and morphogenesis in Arabidopsis. Funded by ANPCyT, Conicet, UNMdP, CIC.