Exogenous application of methyl jasmonate altersPinus resinosaseedling response to simulated frost

Abstract

Physical stresses, such as exposure to cold, can affect plant recruitment, survival, and demography. The ability of plants to tolerate physical stress, however, may depend upon the co-occurrence of other stresses. For example, although plants undergo physiological changes to increase defense against herbivores, it is unknown whether chemical signaling associated with herbivory can alter plant tolerance to cold. We tested the hypothesis that both tissue removal and chemical induction (via exogenous application of 1 mmol/L methyl jasmonate [MeJA]) would alter cold tolerance of seedlings of Pinus resinosa Aiton. Application of MeJA resulted in 18% less foliar tissue damage compared with the control plants (estimated via foliar electrolyte leakage) following a simulated frost. Leaf tissue removal similarly limited the extent of cold damage on P. resinosa seedlings. Growth in seedlings not treated with MeJA was slower than that of seedlings treated with MeJA following exposure to the simulated frost. Our work indicates that secondary responses via MeJA induction can alter tree seedling response to cold and may (i) help explain natural patterns of variation in plant performance, and (ii) be leveraged to facilitate agricultural plant tolerance to physical stresses under increasingly variable climate conditions.