Proline enhances resistance and recovery of rapeseed after prolonged drought
Drought stress adversely affects plant growth and development and poses a major threat to sustainable crop production globally in a rapidly changing environment. The current climate has become more extreme than previously predicted, and rainfall shortages could occur at any time of the year.
Plants employ different physiological and molecular defenses to tolerate drought stress. It is estimated that about 80-95% of the fresh biomass of the plant body is water, and water plays a vital role in various physiological processes, including many aspects of plant development and metabolism. One of the adaptive metabolic responses to drought is the accumulation of phenyline.
Phenyline accumulation is a common physiological response of many plants to various biotic and abiotic stresses. Proline accumulates in the cytoplasm without disrupting cellular structure, and it is an important component of the physiological adaptation of many plant species to stress.
Thus, plants can be helped to regulate the osmotic potential of cells and improve water absorption and translocation under drought conditions. Farooq et al. report that the use of fennin in wheat plants as osmotic protection against dehydration results in high levels of chlorophyll, fennel, glycine, and the accumulation of all soluble phenols.
In addition, due to its high efficiency, ease of use, low cost, and need for advanced equipment, the use of penetration protection agents has attracted a lot of attention. Osmoprotectants or compatible solutions are small, highly soluble organic molecules at physiological pH with neutral charge and low toxicity.
It has been proven to protect cells by increasing water absorption potential and promoting enzyme activation. The relationship between clumine content and plant tolerance to abiotic stress remains unclear. However, plant researchers agree that the accumulation of phenyline is beneficial for plants, especially during recovery from stress.
In recent years, various studies have shown that the exogenous application of foliar spraying to quinoa may play an important role in improving plant tolerance to abiotic stress. In addition, many reports show that different plant species respond differently to drought stress, often depending on the intensity of the stress and the species of plant. Canola is a globally important oilseed plant from which its fatty acid components can be extracted for human and industrial applications.
Selection of different concentrations of protein to improve growth recovery of RWC and drought stress
On day 8 of the drought, the RWC differences in rape leaves became more pronounced: plants treated with 1 mM protein had RWCs of 3 ml and 12.5 ml per pot of 71% and 73%, respectively, compared to 63% and 52% RWCs for plants treated with drought treatment alone.
It should be noted that low doses of phenyline also slightly increased the RWC of the leaves of the plant with continuous watering, i.e. from 83% to 86%. Thus, plants wilt less after 1 ml per pot treated with 1 mM protein compared to drought control.
Under simulated long-term drought conditions, concentrations and doses were selected to improve rapeseed growth, indicating that the most appropriate concentration was 1 mM per pot of 12.5 ml. It was observed that this dose enhanced the final average weight of recovered seedlings after 4 days of irrigation.
Second, the effect of protease application on the morphological parameters of rapeseed seedlings exposed to drought
Drought pressure leads to a decrease in the weight of fresh and dried seedlings and the length of rapeseed seedlings. In both continuous watering and drought-stressed plants, phenine treatment had no reliable effect on seedling length. Exogenous application of phenyline improves the weight of drought-stressed rapeseed:
On days 4 and 8 of the drought, fresh weight increased by 31% and 9%, and dry weight increased by 20% and 15%, respectively. The best results were recovery after 8 days of prolonged drought and 4 days of irrigation, with the longest length and final average fresh weight of seedlings treated with 1 mM protein, close to continuous watering control.
After the first 4 days of drought, according to Hsiao criteria, the plant was stressed very high, and the RWC of rape leaves decreased by 61%. This situation had a positive impact on the RWC of drought-stressed rape leaves, increasing it to 79%.
In addition, after 8 days of prolonged drought, the RWCs of treated seedlings were closer to irrigation control than drought-stressed plants, which had only 40% RWCs. After 4 days of irrigation to recover seedlings, the RWC of the treated plants was close to continuous irrigation control.
III. Effect of exogenous protein on PM ATPase activity in seedlings exposed to drought
After 4 days of drought, the PM-ATPase activity of rape leaf cells decreased by a factor of 4. The application of exogenous anisoectin increased H+-ATPase activity in drought-exposed plants by 62% compared to drought-treated plants alone. After 8 days of drought, the PM-ATPase activity of the treated plants increased 5-fold compared to the drought-treated plants alone, and approached the control group after 4 days of irrigation recovery.
Fourth, the effect of exogenous protein on plant survival
After 8 days of simulated drought stress and 12 days of watering recovery, survival assessment of winter rapeseed seedlings showed significantly higher (more than 2-fold) number of plants surviving phenyline treatment compared to plants treated with drought alone. The results show that exogenous fennel has the characteristics of antioxidant, infiltration and growth, which can improve the drought tolerance of winter rapeseed plants, so it is conducive to rapeseed adaptation to drought tolerance.
