Taneja Mehak, Tyagi Shivi, Sharma Shailesh, Upadhyay Santosh Kumar
Department of Botany, Panjab University Chandigarh, India.
National Agri-Food Biotechnology Institute Mohali, India.
Front Plant Sci. 2016 Nov 28;7:1775. doi: 10.3389/fpls.2016.01775. eCollection 2016.
The Ca/cation antiporters (CaCA) superfamily proteins play vital function in Ca ion homeostasis, which is an important event during development and defense response. Molecular characterization of these proteins has been performed in certain plants, but they are still not characterized in (bread wheat). Herein, we identified 34 TaCaCA superfamily proteins, which were classified into TaCAX, TaCCX, TaNCL, and TaMHX protein families based on their structural organization and evolutionary relation with earlier reported proteins. Since the comprises an allohexaploid genome, genes were derived from each A, B, and D subgenome and homeologous chromosome (HC), except chromosome-group 1. Majority of genes were derived from more than one HCs in each family that were considered as homeologous genes (HGs) due to their high similarity with each other. These HGs showed comparable gene and protein structures in terms of exon/intron organization and domain architecture. Majority of TaCaCA proteins comprised two Na_Ca_ex domains. However, TaNCLs consisted of an additional EF-hand domain with calcium binding motifs. Each TaCaCA protein family consisted of about 10 transmembrane and two α-repeat regions with specifically conserved signature motifs except TaNCL, which had single α-repeat. Variable expression of most of the genes during various developmental stages suggested their specified role in development. However, constitutively high expression of a few genes like and indicated their role throughout the plant growth and development. The modulated expression of certain genes during biotic (fungal infections) and abiotic stresses (heat, drought, salt) suggested their role in stress response. Majority of and family genes were found highly affected during various abiotic stresses. However, the role of individual gene needs to be established. The present study unfolded the opportunity for detail functional characterization of TaCaCA proteins and their utilization in future crop improvement programs.
钙/阳离子反向转运蛋白（CaCA）超家族蛋白在钙离子稳态中发挥着至关重要的作用，而钙离子稳态是发育和防御反应过程中的一个重要事件。这些蛋白的分子特征已在某些植物中进行了研究，但在（普通小麦）中仍未得到表征。在此，我们鉴定了34个TaCaCA超家族蛋白，根据其结构组织以及与先前报道蛋白的进化关系，将它们分为TaCAX、TaCCX、TaNCL和TaMHX蛋白家族。由于（普通小麦）包含一个异源六倍体基因组，除了第1染色体组外，每个A、B和D亚基因组以及同源染色体（HC）都有基因。每个家族中的大多数基因都来自多个HC，由于它们彼此高度相似，因此被视为同源基因（HG）。这些HG在外显子/内含子组织和结构域结构方面显示出可比的基因和蛋白质结构。大多数TaCaCA蛋白包含两个Na_Ca_ex结构域。然而，TaNCLs还包含一个带有钙结合基序的额外EF手结构域。每个TaCaCA蛋白家族由大约10个跨膜区和两个α重复区域组成，具有特定保守的特征基序，但TaNCL除外，它只有一个α重复。大多数（普通小麦）基因在不同发育阶段的表达变化表明它们在发育中具有特定作用。然而，一些基因如（此处基因名缺失）和（此处基因名缺失）的持续高表达表明它们在整个植物生长发育过程中发挥作用。某些基因在生物（真菌感染）和非生物胁迫（热、干旱、盐）期间的表达受到调控，表明它们在胁迫反应中发挥作用。在各种非生物胁迫下，大多数（此处家族名缺失）和（此处家族名缺失）家族基因受到高度影响。然而，单个基因的作用仍需确定。本研究为TaCaCA蛋白的详细功能表征及其在未来作物改良计划中的应用提供了机会。
