Response to water stress in transgenic (p5cs gene) wheat plants (Triticum aestivum L.)

Abstract

Transgenic technology in plants has been used to introduce genes that perform as osmoprotection to obtain tolerant to abiotic stresses genotypes. Proline is considered as one of these osmoprotectors. Therefore, Δ1-pirrolyne-5-carboxylate synthesize (P5CS) enzyme, coded by p5cs gene is important and also a limiting factor in its pathway synthesis. This work aimed to evaluate proline accumulation in p5cs gene-transformed wheat plants. Experiment was conducted in randomized entirely design with 18 treatments (seven second generation (T2) transgenic plants, nine first generation (T1) transgenic plants and two checks with and without irrigation) and ten replications. Leaves were collected for conducting analyses of proline content, lipid peroxidation and water relative content every four days. The data were subjected to analyses of variance, using F-test at 1% and 5% probability levels and means grouped by Scott and Knott test at 5% probability level. The results showed that both transgenic and non-transgenic irrigated plants suffered reduction of water accumulation in relation to non-transgenic and plants without irrigation. However, they resisted eight days without water supply and with turgidity. Transgenic plants with constituted promoter (Ubi) and induced stress promoter (aipc) did not present significant differences in relation to proline levels. Lipid peroxidation values did not show any difference between transgenic plants and non-transgenic plants under no irrigation treatments during the evaluation period. The results indicated that transgenic plants produced approximately 1.85 more proline content than normal, demonstrating the p5cs gene expression.