The expressions of CsHSFs gene in relation to chilling tolerance of cucumber fruits

Objective The relationship between the expression patterns of CsHSFs genes and the chilling tolerance of cucumber fruits treated by heat shock and cold acclimation treatments were analyzed.

Method Relative electrolyte leakages, total soluble solids (TSS), contents of chlorophyll and color in cucumber fruits pre-treated by heat shock (pre-treated by 50 ℃ hot water for 1 min) or cold acclimation (pre-storage at 15 ℃ for 2 day) were investigated during low temperature storage (8 ℃), and the expression of CsHSFs gene was determined using qRT-PCR.

Result and conclusion The results showed that the pretreatments with heat shock and cold acclimation enhanced the chilling tolerance in cucumber fruit, reflected by inhiting increase in relative electrolyte leakages and a decrease in chlorophyll contents in heat shock or cold acclimation-treated fruits, with a stronger effect created by cold acclimation treatment. There was no significant difference in TSS content between the two treatments.Moreover, the expression levels of CsHSF7 and CsHSF11 genes significantly increased in heat shock and cold acclimation treatments compared to the control, suggesting that they were likely to get closely involved in the chilling tolerance induced by heat shock and cold acclimation in cucumber fruits.However, CsHSF7 and CsHSF11 genes might participate in the response to chilling with different mechanisms, as CsHSF7 showed transcriptional activation in yeast cells, while CsHSF11 did not.