Quantitative mRNA Expression Profiles of Germin-Like and Extensin-Like Proteins under Drought Stress in Triticum aestivum

Drought stress can severaly damage plant growth and the most important factor in the reduction of wheat yield in cultivated areas. Development of new methodologies to improve wheat productivity and quality under drought conditions has a primary importance Extensin-like and Germin-like Protein transcripts were selected from our RNAseq data for their relation with defense mechanism. We aim to show the expression patterns of these genes in drought tolerant and non-tolerant T. aestivum cultivars under drought stress conditions using qRT-PCR technique. Extensin is the most abundant proteins present in the cell wall of higher plants and has an important role in plant defense through strengthening the cell wall and preventing tissue damage. GLPs are involve in different biological processes; e.g., disease resistance and superoxide scavenging metabolism. We established different mRNA expression regulation of Extensin like and Germin-like mRNAs in root and leaf tissues of tolerant and non-tolerant T. aestivum cultivars under drought stress. We observed GLP transcript was significantly up-regulated (5 fold) in 4h drought- stressed root tissues of tolerant cultivar Gerek and then decreased in 8h. On the other hand there was no dramatic difference in leaf tissue of each cultivar. Extensin-like gene up-regulation was approximately 6 and 3.5 fold in 4h stressed root tissues of tolerant cultivars. In leaf tissues, different expression pattern was observed in tolerant and non-tolerant cultivars. Drought stress caused to up-regulation (4 fold) in 4h stressed leaf tissues of tolerant cultivar. On the contrary, down-regulation (4 fold) was identified in non-tolerant stressed leaf tissues. These results suggest that overexpression of Extensin-like gene under drought stress conditions may offer drought tolerance. The qRTPCR results from root and leaf tissues from 3 different cultivars were in agreement with our RNAseq data. This is the first report shows the expression profiles of these defense proteins under drought stress conditions in T. aestivum.