摘要：Temperature stress restricts plant growth and development. Antifreeze protein (AFP) can improve plants antifreeze ability. In our previous study, the
AnAFP gene cloned from
Ammopiptanthus nanus was confirmed to be an excellent candidate enhancing plant cold resistance. But, AnAFP protein shared similar structures with KnS type dehydrins including K, N and S domains except ice crystal binding domain A. Here, we generated
AnAFPΔA,
AnAFPΔK,
AnAFPΔN and
AnAFPΔS, and transformed them into ordinary and cold sensitive strains of
E. coli, and
Arabidopsis KS type dehydrin mutant to evaluate their function. Expression of
AnAFPΔA decreases cold and heat tolerance in
E. coli, meanwhile, AnAFP enhances heat tolerance in
Arabidopsis, suggesting that domain A is a thermal stable functional domain. AnAFP, AnAFPΔA and AnAFPΔS localize in whole cell, but AnAFPΔK and AnAFPΔN only localizes in nucleus and cytoplasm, respectively, exhibiting that K and N domains control localization of AnAFP. Likewise, K domain blocks interaction between AnAFP and AnICE1. The result of RT-qPCR showed that expression of
AnAFP,
AnICE1 and
AnCBF genes was significantly induced by high-temperature, indicating that the
AnAFP is likely regulated by ICE1-CBF-COR signal pathway. Taken together, the study provides insights into understanding the mechanism of AnAFP in response to temperature stress and gene resource to improve heat or cold tolerance of plants in transgenic engineering.
