Leaf anatomy of maize inoculated with plant growth-promoting bacteria under different water conditions

Adopting plant growth-promoting bacteria configures a new technology with sustainable potential for maize production. Maize anatomy with this type of interaction is used as a tool to understand the structural mechanisms of plants, especially when planted under water stress conditions. This study sought to evaluate the leaf anatomy of maize plants inoculated with plant growth-promoting bacteria under different water stress conditions. Experiments were conducted in randomized blocks using a factorial scheme of five (inoculation with A. brasilense, inoculation with B. aryabhattai, combination of A. brasilense + B. aryabhattai, positive control and negative control) x three irrigation levels (water depths of 25%, 50% and 75% of field capacity), totaling 15 treatments. Evaluations were carried out after the plants reached the V6 stage of development. Leaf sections were performed to measure epidermis thickness and leaf mesophyll, and to quantify and measure the thickness of stomatal structures. Significant differences in the thickness of the upper and lower epidermis, in the mesophyll, and in the stomatal characteristics according to treatments were found. While A. brasilense promoted greater thickness of the upper epidermis under low water availability, B. aryabhattai had a greater effect on the lower epidermis at 75% irrigation level of the field capacity. Number and stomatal diameters also varied according to treatment. Overall, plant growth-promoting bacteria influence the leaf anatomy of maize plants under different irrigation levels, evincing their potential in developing plants under water stress.