Antioxidant Enzyme Activities and Gene Expression Patterns in Leaves of Kentucky Bluegrass in Response to Drought and Post-drought Recovery

By Lixin Xu, Liebao Han, Bingru Huang. 2011

116 citations recorded by the source corpus.

The objectives of this study were to examine antioxidant enzyme responses to drought stress and rewatering at both enzymatic activity and transcript levels and to determine the major antioxidant processes associated with drought tolerance and post-drought recovery for a perennial grass species, kentucky bluegrass (Poa pratensis). Antioxidant enzyme responses to drought and rewatering in a drought-tolerant cultivar (Midnight) and a drought-sensitive cultivar (Brilliant) were compared in a growth chamber. Plants were exposed to 22 days of drought stress for 'Midnight' and 18 days for 'Brilliant' before rewatering to allow the leaf relative water content (RWC) of both cultivars to drop to the same level. 'Midnight' exhibited higher photochemical efficiency (Fv/Fm) and lower electrolyte leakage compared with 'Brilliant' when at the same water deficit status (26% to 28% RWC). After 6 days of rewatering, all physiological parameters returned to the control level for 'Midnight', but only Fv/Fm fully recovered for 'Brilliant'. The transcript level of cytosolic copper/zinc superoxide dismutase (cyt Cu/Zn SOD) and ascorbate peroxidase (APX) was significantly higher in 'Midnight' than in 'Brilliant' when exposed to the same level of water deficit (26% to 28% RWC), suggesting that SOD and APX could be involved in scavenging oxidative stress- induced reactive oxygen species in kentucky bluegrass through changes in the level of gene expression. Significantly higher activities of APX, monodehydroascorbate reductase, glutathione reductase, and dehydroascorbate reductase as well as lower lipid peroxidation levels were observed in 'Midnight' versus 'Brilliant' when exposed to drought. However, the activities of SOD, catalase (CAT), and guaiacol peroxidase (POD) did not differ between the two cultivars. After 6 days of rewatering, 'Midnight' displayed significantly higher activity levels of CAT, POD, and APX compared with 'Brilliant'. The enzyme activity results indicate that enzymes involved in the ascorbate-glutathine cycle may play important roles in antioxidant protection to drought damage, whereas CAT, POD, and APX could be associated with better post-drought recovery in kentucky bluegrass.

Subfields: Plant Science

View Paper: https://www.semanticscholar.org/paper/19ff17ce51462aff128a6ba18f51b9d1f36330be

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In Plant Science

1. M. Dacosta
2. Yiwei Jiang
3. Bingru Huang
4. N. Samarah
5. D. Awad
6. A. Harb
7. Emily Merewitz
8. A. Wahid

Citations in the corpus

• Effect of Drought Stress at Reproductive Stages on Growth and Nitrogen Metabolism in Soybean (2020, background): “Previous studies showed that SOD and CAT activities were significantly decreased under prolonged drought stress in Kentucky bluegrass [12,60].”
• Mitigation of Drought Stress Damage by Exogenous Application of a Non-Protein Amino Acid γ– Aminobutyric Acid on Perennial Ryegrass (2013, result): “These results are in accordance with previous studies conducted on perennial turf species in which a reduction in APX and POD activity was observed under drought compared with watered control (Da Costa and Huang, 2007; Xu et al., 2011).”
• Research Advances in Mechanisms of Turfgrass Tolerance to Abiotic Stresses: From Physiology to Molecular Biology (2014, background): “…leaves exhibited different expression patterns in response to drought between two cultivars of Kentucky bluegrass contrasting in drought tolerance (Xu et al., 2011b); the transcript abundance for Cyt APX and Cyt Cu/ZnSOD were significantly higher in the drought-tolerant cultivar than in the…”
• Molecular responses to drought stress in plants (2017, unknown): “Mitochondria play an important role in the avoidance of ROS production by efficient energy dissipation mechanisms (Xu et al. 2011).”
• Gene expression and activity of antioxidant enzymes in barley (Hordeum vulgare L.) under controlled severe drought (2015, methodology): “In a study on Kentucky bluegrass, progressive drought for 18 days of drought-tolerant genotype and 22 days of the drought-sensitive genotype showed an increase in lipid peroxidation in both genotypes, but the increase was higher in the droughtsensitive genotype (Xu et al. 2011).”