Exogenous Ca2+enhances the heat tolerance of cucumber seedlings by im-proving their antioxidant and osmotic regulation capability
ZHENG Dongwen
LI Xuan
HU Xinrui
XI Shibo
XIAO Huaijuan
WANG Jiqing
WANG Hu
Abstract：To explore the mechanism of exogenous Ca2+in regulating the heat tolerance of cucumber seedlings,the cucum-ber variety Jinyou 35 was used as the experimental subject.Five levels of exogenous Ca2+treatments were set,namely 5 mmol·L-1(T1),10 mmol·L-1(T2),20 mmol·L-1(T3),30 mmol·L-1(T4),and 40 mmol·L-1(T5),with distilled water as the control(CK).The aim was to screen the appropriate Ca2+concentration for alleviating the high-temperature stress on cucumber seedlings and to explore the physiological mechanism of Ca2+in mitigating high-temperature stress.The results showed that the T2 treatment could effectively reduce cell damage in cucumber leaves,significantly increase the enzyme activity of POD and APX in cucumber seedlings under high-temperature stress,by 34.33%and 22.71%,respectively,com-pared to CK.The content of soluble protein and proline were significantly increased by 22.65%and 20.04%,respectively,compared to CK,enhancing the antioxidant and osmotic adjustment capabilities of cucumber seedlings.Additionally,the T2 treatment significantly alleviated the inhibitory effects of high-temperature stress on the maximum photochemical effi-ciency Fv/Fm and root activity of cucumber seedlings,increasing them by 21.57%and 30.77%,respectively,compared to CK,thereby maintaining the normal metabolic activity of the aboveground and underground parts of cucumber seedlings under high-temperature stress.In conclusion,10 mmol·L-1 CaCl2 solution is the appropriate concentration for enhancing the heat tolerance of cucumber seedlings and can be applied in cucumber production under high-temperature conditions.
Keywords：CucumberHeat toleranceCa2+Reactive oxygen speciesOsmotic regulation substances
Publication Date：2026-02-05
Online Publishing Date：2026-03-10(First online date of this platform, not the publication date of the document)
Pages：6( 95-100 )