Skip to main content
ARS Home » Research » Publications at this Location » Publication #123378
Title: REDUCTION OF CHILLING INJURY AND EXPRESSION OF HEAT SHOCK PROTEIN GENES IN TOMATOES BY METHYL JASMONATE AND METHYL SALICYLATE

Author
item DING, CHANG-KUI - ZAAS, ZHEJING, CHINA
item Wang, Chien
item Gross, Kenneth
item Smith, David

Submitted to: Plant Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/14/2001
Publication Date: N/A
Citation: N/A

Interpretive Summary: Most tropical or subtropical fruits and vegetables are susceptible to chilling injury. The chill-injured commodities develop symptoms such as pitting, discoloration, internal breakdown, and decay. These symptoms reduce the value and quality of the commodities and can result in substantial losses during storage and marketing. One of the techniques that can alleviate chilling injury is the treatment with natural volatiles such as methyl jasmonate and methyl salicylate. We have previously shown that vapor application of these naturally occurring compounds was effective in reducing chilling injury. However, very little is known about the mechanism of how these natural volatiles exert their effect. This study found that treatment of tomato fruit with methyl jasmonate or methyl salicylate significantly increase the expression of some heat shock proteins. The increase of these proteins were correlated to the protection nagainst chilling injury. Better understanding of the mechanism of how chilling injury is reduced will improve our ability to design more effective methods for maintaining market quality of fresh produce. This research has the potential to benefit the produce industry and consumers.

Technical Abstract: Changes in heat shock protein (HSP) gene expression induced by vapor application of methyl jasmonate (MeJA) and methyl salicylate (MeSA) in tomato fruit were investigated and compared to the well-described heat shock response. Northern hybridization experiments involving six cDNAs, encoding class I and II tomato small HSPs (sHSPs) and three HSP 70 family members, showed that accumulation of class I and II sHSP mRNAs was increased significantly by MeJA and MeSA. When treated fruit were transferred to low temperature, class I and II mRNA levels initially decreased but then subsequently increased. Accumulation of HSP transcripts was also observed in nontreated fruit between 7 and 14 days at low temperature storage, but all decreased to undetectable levels after 21 days. Following MeJA and MeSA treatments, the transcripts of HSP 70 family accumulated to higher levels than following heat treatment. MeJA- and MeSA-treatments were clearly shown to alleviate chilling injury, whereas tomato fruit stored at 5oC without pretreatment developed typical symptoms and severe decay. These results demonstrated that MeJA and MeSA induced the accumulation of sHSP transcripts in tomato. The increased transcript abundance of HSPs, especially class II sHSPs, was correlated with protection against chilling injury.