Fragaria daltoniana and F. vesca Raw sequence reads

Abiotic stresses have increasingly serious effects on the growth and yield of crops. Cold stress, in particular, is an increasing problem. In this study, Fragaria daltoniana and F. vesca were determined to be cold-resistant and cold-sensitive species, respectively. Integrated transcriptomics and metabolomics methods were used to analyze the regulatory mechanism of abscisic acid (ABA) in F. daltoniana and F. vesca in response to low temperature stress. F. daltoniana and F. vesca increased the content of ABA under low temperature stress by up-regulating the level of expression of the ABA biosynthetic pathway gene NCED and down-regulating the level of expression of the ABA degradative gene CYP707A. Both types of regulation increased the accumulation of glucose and fructose, resulting in a reduction of the damage under low temperature stress. Twelve transcription factors were found to be involved in the ABA regulatory pathway. The strong cold tolerance of F. daltoniana could be owing to the higher levels of ABA that accumulated compared with those in F. vesca under low temperature stress. In addition, the gene ABF2 that is related to the transduction of glucose signaling was significantly upregulated in the leaves of F. daltoniana, while it was downregulated in the leaves of F. vesca under low temperature stress. This could contribute to the higher levels of glucose signal transduction in F. daltoniana. Thus, this could be the reason for the higher peroxidase activity and lower damage of cell membranes in the leaves of F. daltoniana compared with F. vesca under low temperature stress, which endows it with stronger cold tolerance.