State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, 430026, China.
Plant Physiol Biochem. 2023 Sep;202:107922. doi: 10.1016/j.plaphy.2023.107922. Epub 2023 Aug 10.
Calmodulin (CaM) and calmodulin-like (CML) proteins are crucial Ca sensors, which are widely involved in different biological processes of plants, including their growth and development, and stress responses. However, the origin and evolution of the CaM/CML gene family in plants remain elusive. In this study, 2133 CaM and 23094 CML genes were identified from the 1000 plants project (1 KP) species and the sequenced plants, covering algae, mosses, monilophytes, lycophytes, flowering plants, and all other green plant branches. Analysis showed that the size of the CML subfamily was correlated with the genome size of corresponding plant species, as well as the total gene number in the genome. Moreover, with the evolution from algae to angiosperms, the number of CML genes in plants increased gradually which could have been driven mainly by genome-wide segmental duplication events, while the number of CaMs remained basically stable at 2-3. Phylogenetic analysis demonstrated that CaM first appeared in green algae, while CML appeared earlier and has already been presented in dinoflagellates. Further analysis showed that the number and sequence of EF-hand domain in CaMs are highly conserved, while those of CMLs are diverse among different plant taxa. Expression analysis revealed that the expression level of CaMs was generally higher than that of CMLs, indicating that the high-expression genes have essential functions, while the low-expression genes are the main reasons for the functional diversity of the CaM/CML gene family in plants. The results might contribute to understanding the evolution of CaM/CML genes as well as their molecular functions.
钙调蛋白（CaM）和钙调蛋白样（CML）蛋白是重要的 Ca 传感器，广泛参与植物的不同生物学过程，包括生长发育和应激反应。然而，植物中 CaM/CML 基因家族的起源和进化仍不清楚。在这项研究中，从 1000 种植物项目（1KP）物种和测序植物中鉴定出 2133 个 CaM 和 23094 个 CML 基因，涵盖藻类、苔藓、单叶植物、石松植物、开花植物和所有其他绿色植物分支。分析表明，CML 亚家族的大小与相应植物物种的基因组大小以及基因组中的总基因数相关。此外，随着从藻类到被子植物的进化，植物中 CML 基因的数量逐渐增加，这可能主要是由全基因组片段复制事件驱动的，而 CaM 的数量基本保持在 2-3 个。系统发育分析表明，CaM 首先出现在绿藻中，而 CML 更早出现，已经存在于甲藻中。进一步分析表明，CaM 中的 EF 手结构域的数量和序列高度保守，而 CML 则在不同的植物类群中多样化。表达分析显示，CaM 的表达水平普遍高于 CML，表明高表达基因具有重要功能，而低表达基因是 CaM/CML 基因家族在植物中功能多样性的主要原因。这些结果可能有助于理解 CaM/CML 基因的进化及其分子功能。
