THE ELICITOR AsES REGULATES RIPENING AND ENHANCES PROTECTION IN AVOCADO AND STRAWBERRY FRUIT

PERATO, SILVIA M.; MARTÍNEZ ZAMORA, MARTÍN G.; SALAZAR, SERGIO M; DÍAZ RICCI, JUAN C.

Paraná, Entre Ríos

Simposio; Plant Biotechnology Symposium. 54º Annual Meeting of the Argentine Society for Biochemistry and Molecular Biology.; 2018

Argentine Society for Biochemistry and Molecular Biology. SAIB

AsES (AcremoniumstrictumElicitor Subtilisin) is a protein capable of inducing a defense response in strawberry (Fragariaananassa) and Arabidopsis thaliana, increasing the resistance against the hemibiotrophic fungal pathogen Colletotrichumacutatum, and the necrotrophic fungus (Botrytis cinerea). It was reported that the defense response observed was due to the activation the salicylic acid (SA), jasmonic acid (JA) and ethylene (ET) signaling pathways. Since AsES activates the metabolism of ET which is involved in many physiological responses we were interested to investigate whether AsES can further regulate ripening of a climacteric fruit such as avocado (Perseaamericana), and a nonclimacteric fruit such as strawberry. The study included the evaluation of ET production, respiratory rate (CO2), weight loss, firmness, color, acidity, and soluble solids. Evaluation of ET formation on fruits treated with AsES showed a significant increase of ET production not only in climacteric fruits (avocado), but also in non-climacteric fruits (strawberry). However, the effect on avocado and strawberry were different. Whereas the ET and CO2 production in avocado presented a peak 3 dpt, in strawberry the ET production was higher but steady along the time, and CO2 exhibits no significant changes as compared with not treated fruits. Evaluations of weight loss showed that avocado fruits treated with AsES exhibited higher rate of weight loss, while strawberries presented lower rates. Firmness was only evaluated in avocado fruits, and results indicated that AsES causes a significant decrease of the firmness during the first 8 days evaluated. Color quality and acidity were only evaluated in strawberry. Results indicated that AsES causes lower color deterioration after the harvest during the first 3 days evaluated, and acidity showed no significant changes. Soluble solid determination revealed a significant increase in avocado and almost no change in strawberry fruit after the treatment. All these data clearly indicate that AsES affects key aspects of ripening and fruit quality either in avocado or strawberry fruit. It was also observed that AsES induced a protection effect against spontaneous natural post-harvest pathogens in avocado and strawberry fruits. Fruits treated with the ethylene competitive inhibitor 1-MPC (1-methylcyclopropene) previous to AsES suggested that the protection effect was due to the activation of the ET defense signaling pathway. These results uncover the potential use of AsES on the postharvest management of fruit ripening and quality, opening new research lines to study different immunization strategies to increase the crop protection to diseases.