The DC1 domain protein BINUCLEATE POLLEN is required for pollen development in Arabidopsis.

JESICA FRIK; GABRIELA CAROLINA PAGNUSSAT; LEONARDO AGUSTÍN ARIAS; CLAUDIA ANAHÍ CASALONGUÉ; SEBASTIAN D'IPPÓLITO; DIEGO FERNANDO FIOL

Buenos Aires

Congreso; Xth Meeting of the Latin American Society for Developmental Biology; 2019

Latin American Society for Developmental Biology

Development of the male gametophyte is a tightly regulated process thatrequires precise control of cell division and gene expression. Arelevant aspect to understand the events underlying pollen developmentregulation constitutes the identification and characterization of thegenes required for this process. In this work we showed that the DC1domain protein BINUCLEATE POLLEN (BNP) is essential for pollendevelopment and germination. Pollen grains carrying the defective BNPallele failed to complete mitosis II and are impaired in pollengermination. By yeast two hybrid screening and bimolecular fluorescencecomplementation assays, we identified a set of BNP-interacting proteins.Among confirmed interactors we found NAC family transcriptionalregulators Vascular plant One‐Zinc finger 1 (VOZ1) and VOZ2. BNP andVOZ1/2 proteins were mainly detected co-localized in prevacuolarcompartments. As voz1voz2 double mutants showed the same developmentaldefect observed in bnp pollen grains, we propose that BNP requirement tocomplete microgametogenesis could be linked to its interaction withVOZ1/2 proteins. By studying VOZ1 localization in pollen from bnp/BNPplants, we showed that VOZ1 nuclear localization requires BNP. Wepropose that BNP is acting as a scaffold protein recruiting VOZ1 andlikely VOZ2 to prevacuolar compartments into assemblies that couldmodulate VOZ1/2 translocation to the nucleus and therefore modulatetheir activity as transcriptional regulators.