Calcium-dependent protein kinase (CDPK) and its substrates play important roles in plant response to stress. So far, the documentation on the characterization of the CDPK and downstream interaction components (especially transcription factors, TFs) is limited. In the present study, an interaction between CgCDPK (protein kinase) (accession no. MW26306) and CgbHLH001 (TF) (accession no. MT797813) from a halophyte Chenopodium glaucum was further dissected. Firstly, we revealed that the probable nature between the CgCDPK and CgbHLH001 interaction was the phosphorylation, and the N-terminus of CgbHLH001, especially the 96th serine (the potential phosphorylation site) within it, was essential for the interaction, whereas the mutation of ⁹⁶Ser to alanine did not change its nuclear localization, which was determined by the N-terminus and bHLH domain together. Furthermore, we verified the function of CgbHLH001 gene in response to stress by ectopic overexpression in tobacco; the transgenic lines presented enhanced stress tolerance probably by improving physiological performance and stress-related gene expression. In conclusion, we characterized the biological significance of the interaction between CDPK and bHLH in C. glaucum and verified the positive function of CgbHLH001 in stress tolerance, which may supply more evidence in better understanding of the CDPK signaling pathway in response to adversity.

钙依赖性蛋白激酶（CDPK）及其底物在植物对逆境的反应中起重要作用。到目前为止，关于CDPK和下游相互作用成分（尤其是转录因子，TF）的表征的文献有限。在本研究中，CgCDPK（蛋白激酶）之间的相互作用（登录号MW26306）和CgbHLH001（TF）（登录号 MT797813）从盐生植物 青藜被进一步解剖。首先，我们揭示了CgCDPK和CgbHLH001相互作用之间的可能性质是磷酸化，而CgbHLH001的N末端，特别是其中的第96个丝氨酸（潜在的磷酸化位点），对于相互作用是必不可少的，而⁹⁶的突变Ser变为丙氨酸并没有改变其核定位，这是由N端和bHLH结构域共同决定的。此外，我们验证了CgbHLH001响应烟草中异位过表达引起的压力的基因；转基因品系可能通过改善生理性能和与胁迫相关的基因表达而增强了胁迫耐受性。总之，我们表征了CDPK和bHLH之间相互作用的生物学意义。青冈 并验证了CgbHLH001在抗逆性方面的积极作用，这可能为更好地理解CDPK信号通路应对逆境提供更多证据。