| The IRE1a protein is a key player in the response of plant cells to endoplasmic reticulum (ER) stress by activating bZIP60, a transcription factor implicated in effective ER stress response. Natural variation has been observed in the expression of the IRE1a gene in natural accessions of Arabidopsis thaliana, a model plant organism. Here, an attempt is made to correlate basal natural variation of IRE1a with response of the plant to abiotic stress. Abiotic stress response through IRE1a activity, specifically bZIP60 transcript splicing, does correspond to basal IRE1a expression. Additionally, alleles of the IRE1a gene were determined to exist as a result of nucleotide polymorphisms. Such polymorphisms are characterized by nonsynonymous mutations of gene coding regions that affect the amino acid sequence. As the evolution of ecophysiological traits with regards to environmental pressures is of current interest in modern plant biology, the relation of natural selection to the development of IRE1a variation is elucidated based upon conservation of mutations and the diverse geographic range inhabited by Arabidopsis.;Keywords: IRE1a, bZIP60, natural variation, Arabidopsis, abiotic stress. |
