REDUCING CHILLING INJURY AND ENHANCING TRANSCRIPT LEVELS OF HEAT SHOCK PROTEINS, PR-PROTEINS AND ALTERNATIVE OXIDASE BY METHYL JASMONATE AND METHYL SALICYLATE IN TOMATOES AND PEPPERS

Tomatoes (Lycopersicon esculentum L.) and sweet peppers (Capsicum annuum L.) treated with vapors of methyl jasmonate (MeJA) or methyl salicylate (MeSA) had markedly increased resistance to chilling injury and decreased incidence of decay during and after low temperature storage.
Accumulation of classes I and II small heat shock protein (HSP) mRNAs was increased significantly by treatment of tomato fruit with MeJA and MeSA. Treated fruit also accumulated higher levels of transcripts from the HSP 70 family as compared to untreated fruit.
MeJA treatment also substantially enhanced mRNA levels of pathogenesis-related (PR)-2a, PR-2b and PR-3b.
MeSA treated fruit had significantly increased accumulation of PR-2b and PR-3a mRNAs compared to the control fruit.
Two transcripts, 1.5 kb and 3.5 kb, of alternative oxidase (AOX) were detected by Northern blot analysis from sweet pepper fruit stored at 0°C. Both transcripts reached maximal levels first in MeSA treated fruit, second in MeJA treated fruit and last in control fruit.
These results suggest that the treatment of tomatoes and sweet peppers with MeJA or MeSA induces the synthesis of some stress proteins, such as HSP, PR-proteins, and AOX, which leads to increased chilling tolerance and resistance to decay.

V International Postharvest Symposium

C.Y. Wang, R.W.M. Fung, C.K. Ding

postharvest, storage, temperature, quality, Lycopersicon esculentum, Capsicum annuum

https://doi.org/10.17660/ActaHortic.2005.682.58