Crosstalk of putrescine synthetic pathway with abscisic acid signaling pathway in cold tolerance of potato

Low temperature is one of the important environmental factors affecting the growth development of potato. In the previous study, arginine decarboxylase gene ADC1, associated with putrescine synthetic pathway enhances potato cold-acclimated resistance. In this research, to further explore the mechanism by which putrescine pathway regulates potato cold-acclimated resistance, a comparative transcriptome was conducted. GO and KEGG enrichment analysis indicated that ABA signaling pathway was significantly enriched in ADC1 transgenic lines (OE) after cold acclimation. The expression of several genes in ABA signaling pathway, such as three PYLs, two SnRK2s and AREB2, was up-regulated. And ABA could improve cold resistance in potato indicated by reduced electrolyte leakage under freezing temperature and enhance putrescine synthetic pathway indicated by increased expression of ADC1 and putrescine accumulation. There are several ABRE binding sites on the ADC1 promoter, and Dual-Luciferase assay showed that AREB/ABF/ABI5 family members especially AREB2, enhanced the transcriptional activity of the ADC1 promoter. In conclusion, putrescine synthesis pathway improves potato cold -acclimated resistance through up-regulating of ABA signaling pathway. In turn, ABA with AREB2 enhances putrescine synthetic pathway. There exists elaborate feedback regulation between putrescine synthetic pathway and ABA pathway to form cold-acclimated tolerance in potato. The excavation of the mechanism underlying cold resistance provides gene resources and theoretical bases for production practice in potato.

Automated summary

This research reveals that the putrescine synthetic pathway enhances potato cold-acclimated resistance through up-regulating the ABA signaling pathway. Moreover, ABA can also enhance putrescine synthesis. There is an elaborate feedback regulation between the two pathways, forming cold-acclimated tolerance in potato.