Overexpression of StAP- PSI domain in Arabidopsis thaliana increases resistance to B. cinérea

FREY MARIA EUGENIA; D' IPPOLITO, S.; PEPE ALFONSO; TITO FLORENCIA; GUEVARA MARIA GABRIELA; DALEO, GUSTAVO RAUL

Congreso; 52th Annual Meeting Argentine Society for Biochemistry and Molecular Biology; 2016

Aspartic proteases (APs) are a family of proteolytic enzymes widely distributed among living organisms. It was reported that plant APs are involved in various processes as senescence, programmed cell death, reproduction and stress responses. Purpose roles to these APs are to mediate defense responses either by directly processing pathogen related proteins (PR), or to generate elicitors that could potentially be recognized by PR proteins. Previously, in our laboratory we identified, purified and characterized two typical APs from potato (StAP1 and StAP3) that localized in the apoplast. This APs have a a Plant Specific Insert (PSI) and have antimicrobial activity against vegetal and human pathogens.Through the search for sequence homology we detected the presence of three StAP1 highly homologous genes in Arabidopsis. These genes are named as At1g11910 (80% id), At1g62290 (82% id) and At4g04460 (83% id).According with data described in Arabidopsis eFP browser, APA1 (At1g11910 mutant) is induced in leaves after Botrytis cinerea infection and other pathogens. However, there are not data reported that correlate the induction of these genes with the increase or decrease of the defense response of A. thaliana to B. cinerea. In the current study, we evaluate the susceptibility degree of APA1 mutant plants to B. cinerea infection. For this analysis, plants Col-0 and homozygous APA1 mutant lines were infected for 3 days with an inoculum of B. cinerea (1 X 10 5 spores/ml) and the response was analyzed. The APA1 mutant plants developed more severe disease symptoms at 3 days after infection with B. cinerea, including more extensive necrosis and chlorosis with the increased in 94% of lesion area than wild-type plants.In the present work, we show that mutation of the Arabidopsis APA1 gene causes enhanced susceptibility to the necrotrophic fungal pathogen B. cinerea. Therefore, we suggest that this typical AP (At1g11910) would participate in the Arabidopsis defense response against to B. cinerea attack.