Germination rate in Arabidopsis thaliana increases in the absence of cytokinin transporter AZG2

TESSI, TOMÁS MARÍA; PETTINARI, GEORGINA LUCIA; MARTINI, CAROLINA; DESIMONE MARCELO

Corrientes

Congreso; XXXI Argentinian meeting of Plant Physiology; 2016

SAFV

The study of hormones transport has changed the understanding of various developmentalprocesses. Although auxins transport is widely studied, little is known about how their antagonistichormones, cytokinins, are transported. In previous works, we presented AZG2 as a cytokininstransporter involved in the inhibition of lateral root (LR) emergence. This transporter is expressed ina small group of cortical and epidermal cells, immediately above LR primordias. Recently, wedetected expression of AZG2 in micropilar endosperm cells during seed?s coat opening. After 48hsof vernalization and 8h of light exposition, AZG2 expression is induced. This induction takes placein 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 duringgermination, knock out (KO) and overexpressing lines were analyzed. Our results suggest thatAZG2 has a function similar to the LR emergence inhibition during germination. AZG2 KO lineshave more LR than the wild type line while in seeds these KOs show a faster radicle emergencethan in the wild type and overexpressing lines. All these data propose AZG2 as a key regulatorduring root development, probably link to tissue remodeling.