Identification of SNP mutations in MYBYE-1 gene involved in drought stress tolerance in maiz

Abstract

As one of the most important agricultural crops, maize is a staple diet for a large portion of the continuously growing world's human population. Unfortunately, its production is severely affected by adverse environmental stresses such as drought, salt, low and high temperatures. The mechanisms of drought stress tolerance in maize are quite complex and involves a signaling network of genes that controls its adaptation to the stress. Recently, many transcription factors (TFs) for tolerance to drought stress have been identified in maize. In this study, specifically designed primers were used to identify functional single nucleotide polymorphisms (SNPs) in the MYB-like protein E1 (MYBE1) gene of 26 tolerant and sensitive maize inbred lines from the gene banks of Maize Research Institute "Zemun Polje", Serbia and Maize Research Institute, Kneja, Bulgaria by PCR amplification and direct sequencing. Multiple alignments of the sequenced fragments to the drought sensitive US maize inbred B73 and other inbred lines, representing the functional diversity of maize, from the Panzea database (http://www.panzea.org/) was performed. The sequence alignment revealed several SNPs in inbred lines object of this study, one of which unique to the drought tolerant Serbian inbreds T3, T5, T6, T7 and T8. In these lines, the A→G transition, located in the acidic Ser/Thr - rich region of the gene, leads to amino acid change from Tryptophan to Alanine at the corresponding position of the protein. This replacement does not affect the binding site of MYBE-1 transcription factor, but possibly reflects the spatial conformation through changing of its functional activity. This study will contribute the identification of functional markers in genes implicated in the development of drought stress tolerance and their further use for genomic improvement in the national maize selection programs.