Ácido salicílico e metionina mitigam os efeitos deletérios da restrição hídrica em feijão-caupi

Abstract

In the northeastern semiarid, water restriction is a negative factor for vegetables, which reduces productivity and alters plant metabolism. Despite resistance to this abiotic stress, cowpea has modifications in its anatomy and physiology to adapt to the edaphoclimatic conditions of this region, which are attenuated by the use of endogenous or exogenous substances such as salicylic acid and methionine. Based on this, the objective of this research was evaluate foliar application of salicylic acid and methionine in cultivars BRS Pajeu and BRS Nova Era, aiming to mitigate the deleterious effects of water restriction. In the experiment the cultivars BRS Pajeú and BRS Novaera were studied, both submitted to 5 applications of eliciting substances: control (referring to 100% of the pot's field capacity, without eliciting application); stress (referring to 50% of the vessel's field capacity, without the application of an elicitor); stress + application of salicylic acid (1.5 mM); stress + application of methionine (6 mM); stress + salicylic acid (1.5 Mm) + methionine (6 mM). The design was completely randomized, in a 2x5 factorial scheme, with 5 (five) replications. The data were submitted to analysis of variance by F test (P ≤ 0.05), cultivation conditions were compared by Tukey test (P ≤ 0.05), and cultivars were compared by t-student test (P ≤ 0, 05) by Sisvar statistical programme 5.6. Water restriction reduced the water status of plants and increased the content of elicitor molecules such as proline, amino acid and total soluble sugars. The exogenous application of salicylic acid and methionine decreased the deleterious effects of water restriction, helping to maintain the water status of cowpea plants. Also, the antioxidant action of APX, CAT, and SOD were enhanced by the application of salicylic acid and methionine, these elicitors induced an increase in resistance against oxidative damage provided by reactive oxygen species. Between the cultivars, BRS Novaera stands out for the increase in proteins, amino acids, and internal carbon content, provided by the application of salicylic acid and methionine.