Regulation of StTCP15 gene expression and tuber dormancy characteristics of potato by gibberellic acid, abscisic acid, and low temperature

Potato (Solanum tuberosum L.) cv. Eshu 10 was used to investigate the effects of exogenous gibberellic acid (GA3), abscisic acid (ABA), and low-temperature stress on changes of hormone content, expression patterns of StTCP15 gene, and tuber dormancy characteristics. Under GA 3 treatment and low-temperature stress, tuber dormancy was broken in about one week sooner compared with the control group, but ABA treatment did not significantly promote the breaking of tuber dormancy. The results of hormone determination using liquid chromatography-mass spectrometry (LC-MS/MS) showed that the content of ABA in tubers treated with GA(3) or low-temperature stress was lower than in the control group, and it was higher than in the control group under ABA treatment. The GA(3) content of tubers was higher than in the control group under GA(3) treatment and lower under low-temperature stress. During dormancy, the ABA content continued to increase and GA(3) content fluctuated. ABA content rapidly decreased and GA(3) content rapidly increased when the dormancy was breaking, and both ABA content and GA(3) content increased during germination. The results from the assay of real-time quantitative PCR showed that the expression of the StTCP15 gene was continuously increased during the dormant period in all groups, and the expression of the StTCP15 gene was the highest at the time of dormancy release. The expression of the StTCP15 gene was increased about 15 times on the 7th d under low-temperature stress and was restored at room temperature. Thus, the StTCP15 gene can respond to GA(3), ABA, and low-temperature stress and may be involved in the release of potato tuber dormancy.