Estratégias moleculares e fisiológicas para mitigação de estresses abióticos em Setaria viridis

Abstract

Genetic breeding techniques became promising in helping countries to overcome the challenge of growing demand for food, especially in a scenario of scarce resources, such as water. There is a gap regarding the quantitative information on the complex conditions faced by plants, such as drought and high temperature conditions, for example. For most of crops, the transformation and regeneration times used in transgenic methods have low efficiency, and are also time consuming or simply not available. Due to these drawbacks, there is a need to use model plants to perform rapid analysis of potential target genes involved in the responses to abiotic and biotic stresses. In this scenario, Setaria viridis has been demonstrated to be an excellent model for plants performing C4 photosynthesis. This species belongs to the same plant group of crops of high economic importance, such as corn, sorghum and sugarcane. By two different approaches, the study presented here aimed to better understand how this plant responds to drought stress. The first approach was to study the effects of the orphan gene CcUNK8 from Coffea canephora, previously reported as a candidate gene involved in drought tolerance processes in this plant species, through genetic transformation of S. viridis. The second approach was to identify and characterize the S. viridis genes coding the PYL-PYR-RCAR/SnRK2/PP2C proteins of tripartite system involved in the first steps of abscisic acid (ABA) perception in response to abiotic stress. In addition to their potential use biotechnology, the identification of the genes controlling this important signalling pathway as well as the study of their regulation, are essential to better understand the mechanisms involved in plant responses to abiotic stresses.