Expressão de genes de catalase e speróxido dismutase da mandioca durante interação com Phytopythium sp

Abstract

Cassava culture is of great importance worldwide, supplying around 800 million people in the world. In Brazil, the state of Pará stands out in the production of this culture, which is mainly cultivated by family farmers, which guaranteed their subsistence through the marketing and consumption of their derivatives. However, pathogens such as the oomycete Phytopythium sp. cause of soft root rot can compromise its production by up to 100%. Seeking to understand the interaction between Phytopythium sp. and cassava and the mechanisms involved in the response at the molecular level in this interaction, the aim of this research was to analyze changes in the levels of expression of the catalase (CAT) and superoxide dismutase (SOD) genes in detached cassava roots susceptible to infection. Thus, in this work, the search for CAT and SOD gene sequences was initially carried out in the cassava genome available from the Phytozome Database, which resulted in 7 CAT and 9 SOD genes. Of these, 4 CAT and 5 SOD genes were selected, for which the sequences of synthesized primers were determined. Then, semiquantitative RT-PCR assays were performed to evaluate the levels of expression of these genes in detached cassava roots infected with Phytopythium sp. compared to the control (uninfected roots). Differences were observed between the treatment time intervals for each treatment, the largest being the SOD and CAT genes in the 48 hpi period for the inoculated treatment. The results demonstrate that the plant-pathogen interaction increased the expression of the studied genes, which may be involved in the plant's defense mechanism, however, studies of functional analysis of these still need to be further investigated, mainly using over expression and loss of function tests.