Chaperone that binds to RNA, single- (ssDNA) and double-stranded (dsDNA) DNA, and unwinds nucleic acid duplex. Promotes freezing tolerance. Interacts with PTAC16, PABN1, PABN2 and PABN3. Mostly expressed in shoot and root apices, and siliques, and, to a lower extent, in roots, cotyledons, stems, shoots, leaves, floral buds and flowers. In flowers, present in pollen within anthers. High expression in the earliest stage of silique development, with a decrease during the middle stages of silique development and subsequently an increase during the later stages. Accumulates during cold acclimation, especially in roots. Sensitive to freezing. Belongs to the cold shock protein (CSP) family.