Table_8_Calmodulin and calmodulin-like gene family in barley: Identification, characterization and expression analyses.docx

Calmodulin (CaM) and calmodulin-like (CML) proteins are Ca2+ relays and play diverse and multiple roles in plant growth, development and stress responses. However, CaM/CML gene family has not been identified in barley (Hordeum vulgare). In the present study, 5 HvCaMs and 80 HvCMLs were identified through a genome-wide analysis. All HvCaM proteins possessed 4 EF-hand motifs, whereas HvCMLs contained 1 to 4 EF-hand motifs. HvCaM2, HvCaM3 and HvCaM5 coded the same polypeptide although they differed in nucleotide sequence, which was identical to the polypeptides coded by OsCaM1-1, OsCaM1-2 and OsCaM1-3. HvCaMs/CMLs were unevenly distributed over barley 7 chromosomes, and could be phylogenetically classified into 8 groups. HvCaMs/CMLs differed in gene structure, cis-acting elements and tissue expression patterns. Segmental and tandem duplication were observed among HvCaMs/CMLs during evolution. HvCML16, HvCML18, HvCML50 and HvCML78 were dispensable genes and the others were core genes in barley pan-genome. In addition, 14 HvCaM/CML genes were selected to examine their responses to salt, osmotic and low potassium stresses by qRT-PCR, and their expression were stress-and time-dependent. These results facilitate our understanding and further functional identification of HvCaMs/CMLs.

钙调蛋白（Calmodulin，CaM）与类钙调蛋白（calmodulin-like，CML）是Ca²+信号转导介质，在植物生长发育及胁迫响应过程中发挥多样且多重的调控作用。然而，目前尚未在大麦（Hordeum vulgare）中鉴定出CaM/CML基因家族。本研究通过全基因组分析，共鉴定得到5个大麦钙调蛋白（HvCaM）与80个大麦类钙调蛋白（HvCML）基因。所有大麦钙调蛋白均包含4个EF-hand基序，而大麦类钙调蛋白则含有1至4个EF-hand基序。尽管HvCaM2、HvCaM3与HvCaM5的核苷酸序列存在差异，但它们编码的多肽序列完全一致，且与水稻OsCaM1-1、OsCaM1-2及OsCaM1-3编码的多肽序列完全相同。大麦钙调蛋白与类钙调蛋白家族成员在大麦的7条染色体上分布不均，且可通过系统发育分析划分为8个进化类群。该家族基因的基因结构、顺式作用元件与组织表达模式均存在显著差异。在进化历程中，大麦CaM/CML家族基因发生了片段复制与串联复制事件。在大麦泛基因组中，HvCML16、HvCML18、HvCML50及HvCML78属于附属基因，其余家族成员均为核心基因。此外，本研究选取14个HvCaM/CML家族基因，通过qRT-PCR检测其在盐胁迫、渗透胁迫与低钾胁迫下的表达响应，结果显示其表达水平具有胁迫特异性与时间依赖性。上述研究结果有助于深化对大麦钙调蛋白与类钙调蛋白家族的认知，并为其后续功能鉴定提供理论支撑。