Unraveling the role of nitric oxide in drought tolerance in citrus plants

Abstract

Considering the damage caused by water deficit in plants and the future prospects of increasing the frequency and intensity of drought events, studies that explore mechanisms of plant tolerance to water restriction and the participation of cellular chemical signals, such as nitric oxide (NO) should be encouraged. In this context, this is the first study that will seek to understand whether there is a relationship between in Rangpur lime - a drought tolerant rootstock - with the NO signaling, considering that this radical is associated with increased tolerance of plants to drought. The aims to (i) know whether the greater tolerance to drought of the Rangpur lime is related to the greater NO production, evaluating the endogenous production of NO, the oxidative damages (in vitro and in situ), the antioxidant metabolism enzymes, content of S-nitrosothiois, content of amino acids, polyamines and urea, production of auxins, as well as root development; (ii) understand how NO modulates hydraulic conductivity and water transport in citrus, evaluating the root hydraulic conductivity, expression of aquaporins and hydration of tissues. Three experiments will be conducted, the first and the second will seek to understand the mechanisms and characteristics that induce higher drought tolerance, and the third aims to carried out of the species that produce the most NO, enabling early screening of drought-tolerant materials - which can be a tool in citrus breeding programs. Therefore, the present proposal covers basic and applied research, with the citrus sector being the main beneficiary of the results of this research. (AU)