ASPARTIC PROTEASES AND THEIR ROLE IN DROUGHT STRESS

D IPPÓLITO, SEBASTIAN; FREY MARIA EUGENIA; GUEVARA MARIA GABRIELA

Congreso; LIII Reunion Anual de SAIB; 2017

Plant aspartic proteases have been implicated in protein processing as well as in plant senescence, stress responses, programmed cell death and reproduction. In last years, it has been reported that they might have a role in the adaptation of plants to an environment with less water availability. In our laboratory we determined that an A. thaliana gene that encodes for an aspartic protease (At1g11910) that is expressed in guard cell, is induced under deficit water conditions. The aim of this work was to study the role of At1g11910 during the plant response to drought. We performed assays to compare the response of Col-0 and At1g11910 mutant plants in a mild water deficit (MWD) condition. Seedlings of 14 days were putted in pots with an equal substrate quantity and were watered until saturation during 10 days. Then, treated plants were watered until reached a 26% of the maximum substrate capacity (0.13 g of water/g substrate) during the next 20 days. We evaluated the phenotype of each plant under stress conditions and quantified different hydric parameters as water content, consumption and loss. Our results indicated that mutant plants were more susceptible than Col-0 to a MWD, showing a reduction in the total area leaf and in the apical length in a 60% and 40% respectively. On the other hand, we did not observed significant differences in chlorophyll content. We determine that mutant plants had a higher water loss (60%) and consumption (25%) but they presented lower water content (28%). These results allow us to suggest that At1g11910 A. thaliana gene would participate in the tolerance to drought. Currently we are completing the characterization of this gene and generating At1g11910 overexpressing A. thaliana plants as a new biotechnological tool to face water deficit conditions.Keywords: Aspartic Proteases, Drought, A. thaliana.