Interação entre fungos endofíticos melanizados septados da caatinga e genótipos contrastantes de Vigna unguiculata [L.] Walp. sob déficit hídrico

Abstract

Drough is one of the main environmental stresses that limit agricultural productivity, especially in the semi-arid region of the northeast, where crops such as cowpea (Vigna unguiculata) have great socioeconomic importance. Melanized and septate endophytic fungi (DSEs) have been associated with plant growth promotion and the mitigation of water deficit effects, bult their functionality in agricultural crops is still poorly understood. This study avaluated the potential of DSE isolates native to the Caatinga to promove growth and contribute to water stress tolerance in contrasting genotypes of V. unguiculata, Pingo-de-Ouro ,2 (PO) and Santo Inácio (SI). Of the 14 isolated species, 14 colonized cowpea and 11 colonized corn. Among them, the DSE2 strain was selected for showing the best effects of water stress and maintaining plant growth. Inoculation with DSE2 resulted in a higher colonization rate under water stress, especially in the susceptible cultivar (SI). Additionally, it promoted an increase in intrinsic water use efficiency, with a more pronounced effect in the tolerant cultivar (PO). The water regime was the main determining fator for changes in the leaf and root metabolome, while inoculation with DSE2 exerted a secundary modulatory effect. However, in the root system of the SI cultivar, the presence of DSE2 promoted more expressive metabolic reprogramming associated with the response to water stress. The results show that native DSEs from the Caatinga have the potential to modulate physiological and metabolic responses of V.unguiculata under water deficit, with effects depending on the water regime, genotype, and organ analyzed.