CHARACTERIZATION OF CALCIUM TRANSPORTERS DURING THE POLLEN TUBE GROWTH IN Arabidopsis thaliana

GARCIA BOSSI, JULIÁN; MARIANA OBERTELLO; BARBERINI, MARIA LAURA; ESTEVEZ, JOSE; JORGE MUSCHIETTI

Congreso; XXII Reunión Argentina Fisiología Vegetal; 2018

?CHARACTERIZATION OF CALCIUM TRANSPORTERS DURING THE POLLEN TUBE GROWTH IN Arabidopsis thaliana?Julián García Bossi1, Mariana Obertello1, María Laura Barberini1, José Estevez2 y Jorge Muschietti1, 31 Instituto de Investigaciones en Ingeniería Genética y Biología Molecular ?Dr. Hector Torres? (INGEBI?CONICET), Vuelta de Obligado 2490, 1428, CABA, Argentina. 2 Fundación Instituto Leloir, (FIL-IIBBA-CONICET), Av. Patricias Argentinas 435, Buenos Aires, 1405, Argentina. 3 Departamento de Biodiversidad y Biología Experimental, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, 1428 Buenos Aires, ArgentinaIn plants, calcium signals are involved in multiple physiological processes such as stomatal opening, stress responses, and polarized growth of root hairs and pollen tubes. The signals are given as repetitive oscillations of cytosolic free Ca2+ where the intensity and amplitude correlate according to the stimulus. Pollen tube growth occurs through the concerted action of different factors such as pH, ROS, actin and calcium gradient. Any imbalance between these factors causes aborted pollen tubes and therefore, defects in fertility.In this work, we propose to perform a functional study of the P2B type calcium pumps designated as Autoinhibited Ca2+-ATPases (ACAs) in pollen of Arabidopsis thaliana. These pumps are mainly located in vacuoles, endoplasmic reticulum and plasma membranes and are involved in removing calcium from the cytoplasm. Since some Arabidopsis ACAs are specifically expressed in mature pollen, we propose to explore pollen physiology during reproduction of single and multiple ACA mutant plants. We will analyze how the calcium signature is affected with the use of cytoplasmic and endoplasmic reticulum fluorescent calcium biosensors. These results will provide new perspectives about how pollen tube growth is regulated and it will be also applicable for other cellular polar growth models.Key words: Arabidopsis, calcium, pollen tube, ACAs, biosensors