Effect of pretreatment with methyl jasmonate on the response of Pisum sativum to salt stress

Abstract

Summary 10-day-old pea seedlings ( Pisum sativum L. cv. Ran 1) were supplied with 10 −5 M methyl jasmonate for 3 days before salinization with 30 mmol/L NaCl for 3 and 6 days. Salt stress resulted in an increase of free proline content, CO 2 compensation concentration (Γ), photorespiration (R P ), stomatal resistance (r S ), and activity of glycolate oxidase (GO) and phosphoglycolate phosphatase (PGP). Net photosynthetic rate (P N ), transpiration (E), protein content and relative water content (RWC) were decreased. Pretreatment with methyl jasmonate helps the plants to counteract the salt stress or for adaptation to it. P N , RWC and protein content of these seedlings were higher in comparison to NaCl-treated seedlings. Exogenously supplied jasmonate itself plays the role of a stressor that causes typical stress responses — accumulation of free proline, high R P and Γ. Pretreatment with methyl jasmonate leads to a decrease of Na + and Cl − accumulation in the shoot. This protection is discussed with respect to involvement of methyl jasmonate in osmoregulation or osmoprotection based on increased proline accumulation and decreased ion accumulation.