Study of total protein content, soluble sugar, proline content and P5CS gene expression in leaves of three wheat cultivars under drought stress

Abstract

Objective The present study was designed to identify the physiological and molecular responses of drought stress induced metabolism in plants. Since the studied plants include resistant and susceptible wheat crop, it is important to know the drought tolerance mechanisms in these cultivars in order to improve the resistance and tolerance of drought stress to the climate in Iran. Materials and Methods For this purpose, a factorial experiment based on completely randomized design with three replications was conducted in Mohaghegh Ardebil University in 2018-2019. The main factors included drought stress (35, 60 and 85% of field capacity (control)) and sub factor included three wheat cultivars (Pishgam, Pishtaz and Baharan). Drought stress in the three-leaf stage was applied for 10 days and then the seedlings were sampled to check the total protein content of the solution, the sugar content, proline content and the expression of proline-5-D gene expression -5-carboxyxyl synthase (P5CS) of the leaf tissue sample. Results The results showed that with increasing severity of drought stress, the amount of proline, soluble sugar and total protein increased. The highest and lowest levels of total protein, respectively, belonged to the leading cultivar under conditions of strict control and stress. The highest amount of soluble sugar (75.76 and 91.66 mg / g, respectively, wet weight of leaves) in spring wheat and severe drought stress and the lowest (57.59 and 48.7 mg / g, respectively). Examination of P5SC gene expression showed that the number of transcripts of this gene increases under stress and this shows that this gene plays an important role in responding to stress in plants. Baharan showed higher drought resistance than other cultivars by increasing P5CS gene expression and significant proline production and accumulation under drought stress. Conclusions In general, it is inferred that drought-induced expression key gene involved in the biosynthesis of proline (P5CS) cause increased levels of proline leaves and also with the accumulation of soluble sugar probably causes more stress tolerance in cultivars.

Keywords

• drought stress
• proline
• p5cs gene
• total protein
• wheat