Abstract
BackgroundCalmodulin-like (CML) proteins are a primary family of plant-specific Ca2+ sensors that specifically bind to Ca2+ and deliver a Ca2+ signal. CML proteins have been identified and characterized in many plant species, such as the model plant Arabidopsis and rice. Based on considerable evidence, the roles of CML proteins are crucial in plant growth and development and in the response to various external stimuli. Nevertheless, the characterization and expression profiling of CML genes in Chinese cabbage (Brassica rapa L. ssp. pekinensis) remain limited.ResultsIn this study, a genome-wide search and comprehensive analysis were performed, and a total of 79 BrCML genes were identified in Chinese cabbage. Gene structure analysis revealed that these BrCML genes contained two to four conserved EF-hand motifs. Phylogenetic analysis showed that CML homologs between Chinese cabbage and Arabidopsis shared close relationships. The identified BrCML genes were located across ten chromosomes and three different subgenomes of Chinese cabbage. Moreover, 126 pairs of orthologous CML genes were found among Chinese cabbage, Arabidopsis and Brassica oleracea. Expression analysis revealed that the expression of some BrCML genes was tissue-specific and that of some was susceptible to temperature stress. A putative interaction network of BrCML proteins was proposed, which suggested that BrCML2, BrCML6, BrCML15 and BrCML25 were co-expressed and might play roles in flower development and other relevant biological processes of Chinese cabbage.ConclusionsThe results of this study increased the understanding and characterization of BrCML genes in Chinese cabbage, and will be a rich resource for further studies to investigate BrCML protein function in various developmental processes of Chinese cabbage.
Highlights
Calmodulin-like (CML) proteins are a primary family of plant-specific Ca2+ sensors that bind to Ca2+ and deliver a Ca2+ signal
To identify the putative Calmodulin-like proteins (CMLs) genes of Chinese cabbage, 50 CML protein sequences of Arabidopsis [12] were retrieved and used as the query to search against Brassica database (BRAD)
Homology searching against the BRAD and the NCBI database was performed and 79 BrCML genes were identified in Chinese cabbage, a number comparable with that in previous reports in the model crop Arabidopsis [12, 13, 16]
Summary
Calmodulin-like (CML) proteins are a primary family of plant-specific Ca2+ sensors that bind to Ca2+ and deliver a Ca2+ signal. CML proteins have been identified and characterized in many plant species, such as the model plant Arabidopsis and rice. Calmodulin-like proteins (CMLs) are a large subgroup of plant-specific Ca2+ sensors and are the key components in Ca2+ signal transduction [7, 8]. Sequence divergences of EF-hand motifs in CML proteins contribute to the reception of Ca2+ signals from different stimuli and to recognition and activation of the target [3, 8]. A total of 50 and 32 CML genes have been identified in the model plant Arabidopsis and rice, respectively [12,13,14]. Lists of CML genes were discovered in some vegetable crops, such as tomato, cucumber and common bean [15, 16]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
