The effect of spraying ethephon on low temperature stress in Zoysia japonica

This study used Zoysia japonica as an experimental material to study the influence of low temperature stress on physiological indexes, osmotic substances, and related genes of the proline metabolism pathway. To this end, we detected the expression level of chlorophyll, relative water content, electrical conductivity, soluble sugar, soluble protein, proline content, and related genes under ethephon treatment. Ethephon reduced the decrease in chlorophyll content caused by low temperature stress in Z. japonica. The fold change of relative water content and the electrical conductivity in leaves were also alleviated in ethephon-treated plants. Ethephon may regulate cell osmolytes in Z. japonica by increasing the contents of soluble sugar, soluble protein, and proline. It also upregulated ∆1-pyrroline-5-carboxylate synthetase gene expression and downregulated proline dehydrogenase, but had no effect on ∆1-pyrroline-5-carboxylate reductase, ∆1-pyrroline-5-carboxylate dehydrogenase, and ornithine-δ-aminotransferase gene expression. In conclusion, ethylene spray treatment can alleviate low temperature stress in Z. japonica. This study provides a theoretical basis for the mechanism of action of ethephon in Z. japonica cold tolerance.