GERMINATION RATE IN Arabidopsis thaliana INCREASES IN THE ABSENCE OF CYTOKININ TRANSPORTER AZG2

TESSI, TOMÁS M.; DESIMONE, MARCELO; MARTINI, CAROLINA; PETTINARI, GEORGINA

Corrientes

Congreso; XXXI Argentine Plant Physiology Meeting - XXXI Reunión Argentina de Fisiología Vegetal; 2016

Sociedad Argentina de Fisiología Vegetal

The study of hormones transport has changed the understanding of various developmental processes. Although auxins transport is widely studied, little is known about how their antagonistic hormones, cytokinins, are transported. In previous works, we presented AZG2 as a cytokinins transporter involved in the inhibition of lateral root (LR) emergence. This transporter is expressed in a small group of cortical and epidermal cells, immediately above LR primordias. Recently, we detected expression of AZG2 in micropilar endosperm cells during seed?s coat opening. After 48hs of vernalization and 8h of light exposition, AZG2 expression is induced. This induction takes place in a group of cells below the coat opening which disaggregate almost completely 24 hours later, suggesting high cell wall remodeling activity. Therefore, in order to study the role of AZG2 during germination, knock out (KO) and overexpressing lines were analyzed. Our results suggest that AZG2 has a function similar to the LR emergence inhibition during germination. AZG2 KO lines have more LR than the wild type line while in seeds these KOs show a faster radicle emergence than in the wild type and overexpressing lines. All these data propose AZG2 as a key regulator during root development, probably link to tissue remodeling.