Plasticidade fenotípica de genótipos de feijão (phaseolus vulgaris l.) submetidos a estresse abiótico

Abstract

Bean cultivation (Phaseolus vulgaris L.) has historical, nutritional, and sociocultural importance in Brazil, forming a staple food for different communities and representing an important biological heritage shaped by historical processes of seed selection and conservation. However, intensified climate change and the growing simplification of agroecosystems driven by the capitalist mode of production have created new challenges for agricultural production, especially related to water deficits and changes in light conditions. In this context, this study aimed to analyze the phenotypic plasticity of bean genotypes under abiotic stress by evaluating changes in leaf anatomy under shading and water deficit conditions. The experiment was conducted in a greenhouse, using a randomized block design in a 2 × 2 × 2 factorial arrangement with four replications, involving a local genotype (Carioquinha) and a transgenic cultivar (BRS FC401 RMD). Variables related to leaf anatomy were evaluated, including mesophyll, palisade parenchyma, spongy parenchyma, and stomatal density on both the adaxial and abaxial surfaces. Anatomical analyses were carried out through light microscopy and quantified using ImageJ software. The results showed that water deficit and shading significantly affected leaf anatomical traits, highlighting adaptive responses related to the structural reorganization of photosynthetic tissues. Differences in the expression of phenotypic plasticity between the genotypes were also observed, indicating different strategies for adapting to the environmental conditions applied. The results reinforce that changes in the organization of the mesophyll and in stomatal density are relevant mechanisms for maintaining plant metabolism under stress. Finally, it is reiterated that genetic diversity represents an essential element for the resilience of agroecosystems in the face of the climate emergency, highlighting the importance of conserving genetic resources and valuing traditional seeds as a key factor for sustainable and adaptive agricultural systems in response to the hostility created by the contradiction between society and nature driven by capital.