Identification of CDPK Gene Family in Amorphophallus konjac and AkCDPK15 Functional Analysis Under Drought Stress

Abstract

Background Konjac is an economically important crop that is often threatened by low temperatures, drought, salt, pests, and diseases, leading to reduced yield and quality. Calcium-dependent protein kinases (CDPKs) play crucial roles in plant growth and stress responses, yet their presence and functions in konjac remain unexplored. This study aimed to identify and analyse the CDPK gene family in the Amorphophallus konjac genome. Results We identified 29 CDPK genes categorised into four subgroups that unevenly distributed across 12 chromosomes. Most AkCDPK genes have undergone purifying selection during evolution. Cis-acting element analysis revealed that these genes were involved in phytohormone induction, defence, stress response, and plant development. Expression analysis indicated tissue specificity and responses to salt, drought, low temperature, and Pcc stress. Moreover, AkCDPK15 was cloned and its physicochemical properties and functions were analysed. We found that the protein encoded by AkCDPK15 is mainly localised on the cell membrane, while a small amount aggregates in the nucleus. This protein has eight potential phosphorylation sites and was found to positively promote drought tolerance by regulating the antioxidant system. Conclusions These findings provide a theoretical foundation for future research on the CDPK gene family’s functions in A. konjac, potentially aiding in the development of stress-resistant konjac varieties.