AtERF65 OVEREXPRESSION CAUSES INCREASED SHOOT-BRANCHING AND REDUCED TOLERANCE TO DROUGHT STRESS.

VALLE, EM;; MENGARELLI, DIEGO; ZANOR, MI; OSELLA, AV,

Corrientes

Congreso; RAFV2016; 2016

SAFV

AtERF65 OVEREXPRESSION CAUSES INCREASED SHOOT-BRANCHING AND REDUCED TOLERANCE TO DROUGHT STRESS. Diego Mengarelli, Virginia Osella, Estela Valle, María Inés ZanorInstituto de Biología Molecular y Celular de Rosario-CONICET. Fac de Cs Bioquímicas y Farmacéuticas UNR Environmental stresses greatly affect plant growth and development. One important aspect is the ability to control axillary shoot growth by selective promotion of branching. The over-expression of the ethylene responsive factor AtERF65 leads to increased shoot branching, smaller leaf size and reduced tolerance to drought stress. AtERF65ox lines have increased stomatal density accompanied by higher percentage of open stomata. Leaf stomata are the gates controlling CO2 exchange and water vapor, and allow plant to minimize water loss by the regulation of stomata size and density. Lower stomatal density in terrestrial plants allow to reduce the transpiration rate and to increase water use efficiency. Osmotic adjustment has been considered one of the crucial processes in plant adaptation to drought, and the osmotic compounds synthetized include soluble sugar and amino acids. Metabolite profiling of the lines revealed changes in soluble sugar contents and lignin in the cell wall. Drought responses are mainly regulated by ABA and Rboh-dependent ROS production is required for stomatal closure. AtERF65ox lines have lower levels of ROS when compared with WT. Taking into account that Rboh D transcript levels were found decreased in these lines, we propose that AtERF65 acts in ABA dependent drought plant stress responses.