Abstract
Purpose: Catharanthus roseus is a vital medicinal plant due to its content of alkaloids vincristine and vinblas-tine which are known to have a special interest in the pharmaceutical industries. Little is known about the effects of jasmonic acid (JA) on C. roseus plants grown under saline conditions.
Materials: Pots experiment was conducted to explore the impacts of four treatments of JA (0, 0.50, 1.0, and 1.50 mM) on the growth of C. roseus plants which were irrigated with saline (EC = 5.27 dS m(-1)) or tap water (EC = 0.53 dS m(-1)).
Results: The growth of C. roseus plants was reduced due to the irrigation with saline water; on the other hand, the salinity induced the accumulation of alkaloids. Salt stress induced a 41% increase in the alkaloid yield of C. roseus plants compared to the control plants irrigated with fresh water. Some defense mechanisms including: osmoregulation, ion compartmentalization, and antioxidants accumulation were activated in C. roseus plants upon salt stress. The foliar application of JA to the C. roseus plants increased the growth parameters and miti-gated the salt stress; moreover, it enhanced nutrients uptake. Spraying of C. roseus plants with JA significantly enhanced the biosynthesis of compatible solutes and decreased the activity of pyrogallol peroxidase (PPX) and polyphenol oxidase (PPO). Foliar application of JA increased the alkaloids yield of C. roseus plants.
Conclusion: JA reduced the negative effects of salt stress in C. roseus plants through increasing osmoreg-ulation compounds and regulating the activity of antioxidant enzymes. Spraying of C. roseus with JA could be used as a sustainable strategy for promotion its medicinal property by augmenting secondary metabolites production. (C) 2021 SAAB. Published by Elsevier B.V. All rights reserved.