School of Integrative Plant Science, Cornell University, 134A Plant Science, Ithaca, NY, 14853, USA.
Beijing Advanced Innovation Center for Tree Breeding By Molecular Design, Beijing Forestry University, Beijing, China.
Plant Physiol Biochem. 2019 Jun;139:600-612. doi: 10.1016/j.plaphy.2019.04.014. Epub 2019 Apr 17.
Changes in intracellular calcium (Ca) levels in response to developmental processes or external stimuli serve as signals in eukaryotic cells. These Ca signals are likely perceived through sensor proteins that bind Ca by EF-hand (a helix-loop-helix structure) motif. Calmodulins (CaMs), a group of well-characterized Ca sensors, and calmodulin-like (CMLs) are implicated in a large number of diverse cellular processes, including plant development and stress responses. In this study, apple (Malus × domestica) genes encoding CaM and CML proteins that only possess EF-hand motifs with no other functional domains were analyzed. A total of 4 MdCaM and 58 MdCML genes were identified, which are spread among 16 out of the 17 apple chromosomes. Bioinformatics analyses, including protein characteristics, conserved domain, evolutionary relationships and chromosomal locations, demonstrated the conservation and divergence of MdCaMs/CMLs. In addition, expression analysis showed that MdCaMs/CMLs are expressed in more than one tissue, including shoot tips, roots, mature leaves, flowers and fruit. Furthermore, the expression of some MdCaM/CML members responded to plant hormones (abscisic acid, jasmonic acid) and salt stress, suggesting a potential role of these genes in responses to biotic and abiotic stress. Overexpression of stress-induced MdCML3 gene significantly improved the tolerance of apple calli to salinity and ABA. The identification and characterization of MdCaMs/CMLs in apple lays a foundation for future functional studies of these genes.
细胞内钙（Ca）水平的变化响应于发育过程或外部刺激，作为真核细胞中的信号。这些 Ca 信号可能通过结合 Ca 的传感器蛋白（EF 手结构基序）来感知。钙调蛋白（CaMs）是一组特征明确的 Ca 传感器，而钙调蛋白样蛋白（CMLs）则参与了大量不同的细胞过程，包括植物发育和应激反应。在本研究中，分析了编码仅具有 EF 手结构基序而没有其他功能结构域的 CaM 和 CML 蛋白的苹果（Malus × domestica）基因。共鉴定出 4 个 MdCaM 和 58 个 MdCML 基因，它们分布在苹果的 17 条染色体中的 16 条上。生物信息学分析，包括蛋白特征、保守结构域、进化关系和染色体定位，表明了 MdCaM/CMLs 的保守性和多样性。此外，表达分析表明，MdCaM/CMLs 在多种组织中表达，包括茎尖、根、成熟叶片、花和果实。此外，一些 MdCaM/CML 成员的表达对植物激素（脱落酸、茉莉酸）和盐胁迫有反应，表明这些基因在应对生物和非生物胁迫中可能发挥作用。胁迫诱导的 MdCML3 基因的过表达显著提高了苹果愈伤组织对盐度和 ABA 的耐受性。苹果中 MdCaM/CMLs 的鉴定和特征分析为这些基因的功能研究奠定了基础。
