Functional characteristics of a calcium-dependent protein kinase (MaCDPK1) enduring stress tolerance from Morus atropurpurea Roxb

• Published in: Plant cell, tissue and organ culture Vol. 141; no. 1; pp. 131 - 143
• Main Authors: Cao, Zhenming, He, Qianhua, Wang, Pengwei, Yan, Jiming, Awais, Main Muhammad, Liu, Zicheng, Yan, Huichao, Sun, Jingchen
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01.04.2020; Springer Nature B.V
• Subjects: Abscisic acid; Amino acids; Aspartic acid; Bioinformatics; Biomedical and Life Sciences; Calcium; Calcium ions; Domains; Drought; Enzymatic activity; Enzyme activity; Gene expression; Kinases; Life Sciences; Light effects; Magnesium; Morus atropurpurea; Mutants; Original Article; Plant Genetics and Genomics; Plant Pathology; Plant Physiology; Plant Sciences; Protein kinase; Proteins; Regulatory sequences; Signal processing; Signal transmission; Thorium; ABA; Drought stress; Mulberry; Calcium-dependent protein kinases; Salt stress
• ISSN: 0167-6857; 1573-5044
• DOI: 10.1007/s11240-020-01773-x

Calcium-dependent protein kinases (CDPKs), as an important calcium sensor in plants, are widely involved in the signal transmission process of growth and development, pathogen defense response and biotic or abiotic stress. In this study, we cloned in mulberry leaves, the full-length CDS sequence of MaCDPK1, which encodes 573 amino acids with an isoelectric point of 5.36. Bioinformatics analysis found MaCDPK1 have a classical kinase domain and an EF-hands domain. We obtained the wild-type and the mutant-type of MaCDPK1(CDPK1 and mCDPK1) by prokaryotic expression and purification. Through kinase assay, it was found that CDPK1 has intact enzymatic activity and exhibits Mg 2+ and Ca 2+ dependence with a K m of 30 µM and a V max of 100,000 [RLU]/min/µg. However, the mCDPK1 has no activity, which means that aspartic acid at position 234th is critical for the activity. The 1500 bp upstream of the start codon of the MaCDPK1 gene contains core promoter elements TAAT-box and CAAT-box, and contains response elements associated with adverse signals such as light, drought, and abscisic acid. The tissues expression level of MaCDPK1 gene in different tissues of mulberry trees under different stress conditions reflect complex expression patterns, indicating that the MaCDPK1 gene responded to stress tolerance. These results are likely to indicate that MaCDPK1 positively regulates salt and drought stress in Morus atropurpurea Roxb. Key Message This research explored the basic properties of the MaCDPK1 protein, discovered a key amino acid site associated with enzyme activity, and found its corresponding anti-reversal process.