Study of expression of telomerase gene in oily sunflower under drought stress

Objective Drought is the most common environmental stress, which approximately limits production in 25 percent of the world's land. Drought stress causes changes in plant morphology, physiology and profile of genes expressions. One of the effects of oxidative stress due to drought stress is damage to telomeric DNA. The predominant mechanism of telomere conservation in most eukaryotes is dependent on telomerase activity, which prevents shortening of the chromosome end. In the present study the expression of telomerase gene has been investigated in two sunflower tolerant and susceptible genotypes using real time PCR technique. Materials and methods The inbred lines; ENSAT254 and LC1064C were planted in a completely randomized design with three replications in the greenhouse. The plants were kept at 100% crop capacity up to 8 leaf stage in terms of hydration. After this stage, a number of pots were kept at the same capacity, but some others were kept at 80%, 60% and 40% crop capacity. Leaf samples were taken at two times; 7 and 21 days after stress application. RNA was extracted from leaf samples using RNX-plus TM extraction solution (Sinaclone Co., Iran) and real time PCR was conducted using specific telomerase gene primers. Analysis of variance and mean comparison were performed using SAS 9.4 software. Charts were drawn with Excel 2016. Results The results of the mean comparisons showed that the expression of the genes encoding the telomerase enzyme in the sensitive and resistant genotypes of sunflower is different, so that the expression of the gene encoding telomerase enzyme in the resistant genotype (ENSAT254) increased significantly compared to the sensitive one (LC1064C). Conclusions Since telomerase plays an essential role in maintaining genome integrity and stability of cell cycle, therefore, the higher expression of telomerase gene in tolerant genotype (ENSAT254) compared to susceptible one (LC1064C) probably suggests that this gene is involved in resistance of sunflower to drought stress.