Effect of foliar application of methyl jasmonate on tolerance of Physalis peruviana L. to drought stress

Drought stress is the most unfavorable environmental factor that severely reduces plant growth and production. Jasmonates, as the plant growth regulators, and effective in physiological processes, increase plant tolerance to stressful conditions. Physalis is a medicinal plant belonging to Solanaceae family. In order to investigate the effect of methyl jasmonate (MeJA) pretreatment and drought stress on the physiological and biochemical responses of Physalis. A factorial experiment was conducted with the combination of two factors, moisture levels [100% (control), 50%, and 30% of field capacity (FC)] and MeJA levels (0, 50, and 100 µM). Plants were exposed to different levels of moisture for two months, 24h after foliar application of MeJA. The results showed that pretreatmment of plants with MeJA increased leaf area, RWC, total plant dry weight, total chlorophyll, and carotenoids by 36.48, 31.07, 178.53, 37.11, and 49.73%, respectively during drought stress. In this research, application of MeJA, especially concentration of 100 µM, by increasing the contents of soluble sugars (12.13 and 16.69%), proline (22.84 and 45.86%), flavonoids (14.01 and 21.69%), protein (16.53 and 20.98%) and activity of SOD enzyme (22.09 and 13.96%) and decreasing the activities of POD (12.82 and 39.06%), APX (20.85 and 17.33%) and PPO (14.83 and 18.68%) enzymes in the shoot and root, moderated the negative effects of drought stress especially at 30% FC level. Also, MeJA induced changes in the accumulation and distribution of mineral nutrients in stressed plants. The results of this research showed that the foliar application of MeJA by improving the growth and photosynthetic properties, antioxidant system and nutritional status could be an appropriate solution to increase the tolerance of Physalis plant to drought.