Antioxidant defence system and physiological responses of Iranian crested wheatgrass (Agropyron cristatum L.) to drought and salinity stress

作者：Sheikh Mohamadi Mohamad Hossein; Etemadi Nematollah^*; Nikbakht Ali; Arab Mostafa; Majidi Mohammad Mahdi; Pessarakli Mohammad

来源：Acta Physiologiae Plantarum, 2017, 39(11): 245.

DOI：10.1007/s11738-017-2543-1

• Antioxidant enzymes
• Crested wheatgrass
• Drought stress
• Salinity stress
• Turfgrass

Crested wheatgrass (Agropyron cristatum L.) is a cool-season perennial grass, which has demonstrated its potential for use as turfgrass. However, limited information is available on its drought and salinity tolerance. The main purpose of this study was to investigate the changes in the antioxidant defence system and physiological traits of six Iranian crested wheatgrass genotypes under drought and salinity stresses. The experimental design comprised a split plot with water treatments (control well-watered, salinity stress and water stress) as main plots and genotypes as subplots. This study demonstrated the variations in drought and salinity tolerance among crested wheatgrass genotypes. 'ACSKI', 'ACAMI' and 'ACDTI' generally performed better than other genotypes under drought and salinity conditions, mainly by maintaining higher activities of antioxidant enzymes like superoxide dismutase, peroxidase, catalase, ascorbate peroxidase and non-enzyme antioxidants like glutathione, higher proline and total nonstructural carbohydrates content. The increased, decreased, and unchanged activities of antioxidant enzymes in the crested wheatgrass genotypes indicates a different forms of metabolism of antioxidant enzymes in response to drought and salinity stress. In general, drought and salinity stress increases the malondialdehyde (MDA) content and hydrogen peroxide (H2O2) content; however, 'ACSKI', 'ACAMI' and 'ACDTI' genotypes could tolerate an increase in MDA content and H2O2 content; therefore, lower levels of MDA content and H2O2 content were observed. The results showed that increasing levels of diamine oxidase and polyamine oxidase have been associated with increasing drought and salinity tolerance. Based on the biochemical and physiological parameters that were evaluated, we concluded that the genotype 'ACSKI' was superior in terms of drought and salinity tolerance. This superiority was mainly a result of better enzymatic and non-enzymatic antioxidant defence system and better osmotic adjustment under stress conditions.

• 出版日期2017-11