Abstract: Calmodulin-like proteins (CMLs) are important calcium signaling proteins in plants, which play a pivotal role in abiotic stress. In this study, one-year-old tea cutting seedlings of ‘Longjing43’, ‘Fuding Dabai’ and ‘Huangjinya’ were used as research materials. The physiological changes of the three tea cultivars were explored to preliminarily screen the cold-resistance tea cultivar. The CsCML16 gene was cloned to analyze its expression patterns in different cold-tolerance tea cultivars under low temperature stress. The results show that ‘Longjing43’ had the highest cold tolerance under low temperature stress, followed by ‘Fuding Dabai’ and ‘Huangjinya’. CsCML16 gene was cloned from ‘Longjing43’. Sequence analysis shows that the CDS length of CsCML16 is 480 bp, encodes 160 amino acids, contains EF-hand conserved domains with molecular weight of 17.58 kDa. Subcellular localization assay indicates that CsCML16 localized in the nucleus and plasma membrane. Quantitative real-time PCR analysis reveals that CsCML16 gene was involved in the regulation of tea plants in response to low temperature stress, and its expression levels varied with tea cultivars with different cold tolerance. This study provided a basis for further study on the biological function of CsCML16 gene.

Key words: Camellia sinensis, calmodulin-like protein, low temperature stress, physiological analysis, expression analysis