Expressão gênica de tiorredoxinas h em eucalipto em resposta ao estresse salino

Abstract

Eucalyptus grandis is the first eucalyptus species to have its genome fully sequenced and published in 2014. The plant is of great economic interest to Brazil and currently has a planted area of 7.84 million hectares for pulp production. The species also remains the target of breeding studies through hybrids and genetic transformation for the production of transgenic plants already released for experimental planting. The objective of this work is to study the gene expression of three genes encoding E. grandis cytoplasmic thioredoxins, Eucgr.F01604.1, Eucgr.F01854.1 and Eucgr.I02383.1. The technical approach in question involves in silico analysis and a saline stress response condition in seedlings in the laboratory as well as in adult individuals kept in experimental planting. The methodology used to obtain seedlings is to submit pelletized seeds in plates containing filter paper moistened in solutions with two NaCl concentrations, besides the control in three treatments, control, 50mM and 100mM NaCL. Adult plants are specimens of the TECHS experiment (Clonal Eucalyptus Tolerance to Water, Thermal and Biotic Stress) maintained at the Academic Unit Specialized in Agricultural Sciences of the Federal University of Rio Grande do Norte. RT-PCR assays were performed from total RNA extraction from seedlings subjected to saline stress and from adult TECHS plants. CDNA libraries were obtained from total RNA extracted from plant material and PCR reactions were performed with the primer oligonucleotides specific for the three genes studied. Semi-quantitative gene expression was estimated in DNA electrophoresis gels. An in silico analysis of the promoter sequences of the studied genes was also performed to identify regulatory protein binding domains involved with the salt stress response. The results show that E. grandis seedlings respond to saline stress and constitute a good plant material for functional analysis of plant genes. At the same time, there is a correlation between the salt stress response and the possible intervention of transcription factors such as MYC1 in coexpression with the Eucgr.F01604.1 gene.