Characterization of calcium transporters during the pollen tube growth in Arabidopsis thaliana

GARCIA BOSSI, JULIAN; OBERTELLO, MARIANA; BARBERINI, MARIA LAURA; SANLINAS, NICOLAS; ESTEVEZ, JOSÉ; MUSCHIETTI, JORGE

Congreso; XXXIII Reunión Argentina de Fisiología Vegetal; 2021

Santa Fe, Argentina

In plants, calcium signals are involved in multiple physiologicalprocesses such as stomatal opening, stress responses, and polarized growth ofroot hairs and pollen tubes. These signals are given as repetitive oscillationsof cytosolic free Ca2+ where the intensity and amplitude correlateaccording to the stimulus. Pollen tube growth occurs through the concertedaction of different factors such as pH, ROS, actin and calcium gradient. Anyimbalance 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 typecalcium pumps (Autoinhibited Ca2+-ATPases,ACAs), in pollen tubes of Arabidopsis thaliana. These pumps are mainlylocated in vacuole, endoplasmic reticulum and/or plasma membrane and are involvedin removing calcium from the cytoplasm. Studies conducted with ACA insertionalmutants have shown that these pumps have a role beyond the maintenance of Ca2+homeostasis. Since some Arabidopsis ACAs are specifically expressed inmature pollen, we propose to explore pollen-pistil interactions of ACA mutantplants.  We will also study calciumdynamics during pollen tube growth. These resultswill provide new perspectives about how pollen tube growth is regulated and itwill be also applicable to other cellular polar growth models.