engleski

Plant aminoacyl-tRNA synthetases in abiotic stress

Aminoacyl-tRNA synthetases (AARS) are essential enzymes that covalently link amino acid and tRNA. Aminoacylated tRNAs are substrates for protein translation on ribosomes. Besides their central role in translation, AARSs from various organisms participate in other essential cellular processes. However, there are only two reports on noncanonical functions of plant AARSs. Arabidopsis aspartyl-tRNA synthetase and rice methionyl-tRNA synthetase are involved in plant defense mechanisms against pathogen attack. In order to reveal novel noncanonical functions of plant AARSs, we determined the expression levels of selected AARS genes in Arabidopsis thaliana seedlings exposed to various abiotic stress conditions (high heavy metal concentration (cadmium), salinity and osmotic stress) using RT- qPCR. In another set of experiments, we analyzed two transgenic A. thaliana lines. The transgenic lines contained a transgene consisting of coding sequences for seryl-tRNA synthetase (SerRS) and a tag (either GFP or TAP) under regulation of a constitutive promoter. Using RT-qPCR we determined overexpression levels of SerRS transgenes. Western blot analysis and aminoacylation assays showed that the fusion SerRS proteins are active. The two transgenic lines and wild type A. thaliana seedlings were grown on medium containing different stressors (cadmium, salt, and mannitol) and the length of the roots was monitored for several days. Our results indicate that AARSs could have a role in cellular response to abiotic stress in plants.

plant aminoacyl-tRNA synthetases ; abiotic stress ; RT-qPCR

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