Effects of SA Treatment on Winter Wheat(Triticum aestivum L.) Sucrose Metabolism in Low Temperature

Salicylic acid(SA), as a signaling molecule involved in stress response can improve plant resistance to a variety of environmental stresses. In the present study, 1 mmol·L-1 SA was applied to deal with the elite freeze-tolerant wheat cultivar ‘Dongnongdongmai1' and the general freeze-tolerant individual ‘Jimai22', under condition of differential temperature such as 4, 0, –10, and –25 ℃ in the field. We measured the sucrose content, activities of key enzymes and gene expression levels to explore the effects of SA on sucrose metabolism in low temperature. The results showed that, SA treatment increased the content of sucrose in leaves and tillering nodes of ‘Dongnongdongmai1', while had a less significant effect on the ‘Jimai22'. It also increased the enzymes(sucrose phosphate synthetase and sucrose synthetase) activities related to sucrose synthesis and their encoding genes(Ta SPS, Ta Su S) expression levels, reduced the enzyme(soluble acid invertase and alkaline/neutral invertase) activities related to sucrose decomposition activities and their encoding genes(Ta SAInv, Ta A/N-Inv) expression levels. SA treatment will result in the accumulation of sucrose in winter wheat, so as to improve the hardiness of the plant.