Physiological and antioxidative responses associated with drought tolerance of Lasiurus sindicus Henr. endemic to Thar desert, India

Abstract

Sewan (Lasiurus sindicus Henr.) is an endemic fodder grass of low rainfall sandy habitat of hot Indian Thar desert. To understand drought responses and tolerance mechanism in Lasiurus sindicus, seedling growth, root cell viability, changes in enzymatic antioxidants and oxidative injury were assayed at early stage of seedlings in polyethylene glycol (PEG) 6000 (5, 10 and 20%)-induced drought stress. The reduction of seed germination, seedling growth, relative water content and vigor index was found with high level of PEG (10-20%), while 5% PEG slightly increased the germination and the growth parameters. A decline in pigments (Chl a, Chl b, total Chl, carotenoids), chlorophyll stability index, membrane stability index and protein content was observed, which was correlated with increased level of malondialdehyde, an indicator of excess reactive oxygen species. Results showed that increasing level of PEG activated the antioxidative enzymes, superoxide dismutase, peroxidase and catalase. Non-enzymatic antioxidants (ascorbate, phenols) and accumulation of cytosolutes (proline and sugar) for regulation of growth, osmotic potential and reactive oxygen species in drought tolerance. Overall results showed that seeds have adaptive mechanisms for germination and growth under lower level of drought, while increasing drought stress reduced growth potential of L. sindicus. It exhibited drought tolerance features, enhancement in activity of antioxidative enzyme and cytosolutes accumulation which involved in regulation of oxidative damage and osmotic adjustment for survival of the seedlings. Furthermore, our results provide important information about the physiological and antioxidative responses of the seedlings and mechanism associated with drought tolerance of L. sindicus.

Seed Germination Behavior, Growth, Physiology and Antioxidant Metabolism of Four Contrasting Cultivars under Combined Drought and Salinity in Soybean

“…•− ) to less harmful H 2 O 2 , reducing DNA, protein, and damage to the membrane [78]. The enzyme activity levels in all soybeans increased dramatically in this study.…”

Drought tolerance inBrassica napusis accompanied with enhanced antioxidative protection, photosynthetic and hormonal regulation at seedling stage

“…Antioxidant enzymes have critical importance in the scavenging of (Goswami et al, 2020). Our result showed that, under drought stress, SOD activity was higher in ZD622 and ZS11 than cultivar GY605.…”

“…Antioxidant enzymes have critical importance in the scavenging of superoxide ions and resistance to lipidperoxidation. The first enzyme in the antioxidant pathway is SOD, which converts highly reactive OH · radical and superoxide (O .− ) to less toxic H 2 O 2 , which reduces damage to DNA, protein, and membrane (Goswami et al, 2020). Our result showed that, under drought stress, SOD activity was higher in ZD622 and ZS11 than cultivar GY605.…”

The Role of Plant Growth-Promoting Bacteria in Alleviating the Adverse Effects of Drought on Plants

“…Moreover, excessive accumulation of ROS damages photosystem II and obstructs D1 protein synthesis. ROS scavenging mechanisms can be orchestrated by antioxidants (enzymatic or nonenzymatic mechanisms) [113,114]. Enhanced enzymatic antioxidative mechanisms were observed with overproduction of some enzymes, for example CAT, POX, SOD and APX, leading to improved oxidative stress tolerance during, e.g., drought.…”