Identification of CAMTA Gene Family in Heimia myrtifolia and Expression Analysis under Drought Stress

Calmodulin-binding transcription factor (CAMTA) is an important component of plant hormone signal transduction, development, and drought resistance. Based on previous transcriptome data, drought resistance genes of the Heimia myrtifolia CAMTA transcription factor family were predicted in this study. The physicochemical characteristics of amino acids, subcellular localization, transmembrane structure, GO enrichment, and expression patterns were also examined. The results revealed that H. myrtifolia has a total of ten members (HmCAMTA1~10). Phylogenetic tree analysis of the HmCAMTA gene family revealed four different branches. The amino acid composition of CAMTA from H. myrtifolia and Punica granatum was quite similar. In addition, qRT-PCR data showed that the expression levels of HmCAMTA1, HmCAMTA2, and HmCAMTA10 genes increased with the deepening of drought, and the peak values appeared in the T4 treatment. Therefore, it is speculated that the above four genes are involved in the response of H. myrtifolia to drought stress. Additionally, HmCAMTA gene expression was shown to be more abundant in roots and leaves than in other tissues according to tissue-specific expression patterns. This study can be used to learn more about the function of CAMTA family genes and the drought tolerance response mechanism in H. myrtifolia.