Abstract：
Cyclic nucleotide-gated ion channels (CNGCs), as non-selective cation channels, play essential roles in plant growth and stress responses. However, they have not been identified in Qingke (Hordeum vulgare L.). Here, we performed a comprehensive genome-wide identification and function analysis of the HvCNGC gene family to determine its role in drought tolerance. Phylogenetic analysis showed that 27 HvCNGC genes were divided into four groups and unevenly located on seven chromosomes. Transcription analysis revealed that two closely related members of HvCNGC3 and HvCNGC16 were highly induced and the expression of both genes were distinctly different in two extremely drought-tolerant materials. Transient expression revealed that the HvCNGC3 and HvCNGC16 proteins both localized to the plasma membrane and karyotheca. Overexpression of HvCNGC3 and HvCNGC16 in Arabidopsis thaliana led to impaired seed germination and seedling drought tolerance, which was accompanied by higher hydrogen peroxide (H2O2), malondialdehyde (MDA), proline accumulation and increased cell damage. In addition, HvCNGC3 and HvCNGC16-overexpression lines reduced ABA sensitivity, as well as lower expression levels of some ABA biosynthesis and stress-related gene in transgenic lines. Furthermore, Yeast two hybrid (Y2H) and bimolecular fluorescence complementation (BiFC) assays revealed that HvCNGC3 and HvCNGC16 interacted with calmodulin/calmodulin-like proteins (CaM/CML), which, as calcium sensors, participate in the perception and decoding of intracellular calcium signaling. Thus, this study provides information on the CNGC gene family and provides insight into the function and potential regulatory mechanism of HvCNGC3 and HvCNGC16 in drought tolerance in Qingke.
摘要：
环核苷酸门控离子通道（CNGC），作为非选择性阳离子通道，在植物生长和逆境胁迫反应中起着至关重要的作用。然而,它们尚未在清克（HordeumvulgareL.）中被发现。这里,我们对HvCNGC基因家族进行了全面的全基因组鉴定和功能分析，以确定其在耐旱性中的作用。系统发育分析表明，27个HvCNGC基因分为四组，不均匀地位于7条染色体上。转录分析表明，HvCNGC3和HvCNGC16的两个密切相关的成员被高度诱导，并且在两种极端耐旱材料中这两个基因的表达明显不同。瞬时表达表明HvCNGC3和HvCNGC16蛋白均定位在质膜和核囊上。在拟南芥中过度表达HvCNGC3和HvCNGC16导致种子萌发和幼苗耐旱性受损，伴随着更高的过氧化氢（H2O2），丙二醛（MDA），脯氨酸积累和细胞损伤增加。此外,HvCNGC3和HvCNGC16过表达系降低了ABA敏感性，以及转基因品系中某些ABA生物合成和胁迫相关基因的表达水平较低。此外，酵母双杂交（Y2H）和双分子荧光互补（BiFC）分析显示，HvCNGC3和HvCNGC16与钙调蛋白/钙调蛋白样蛋白（CaM/CML）相互作用，which,作为钙传感器，参与细胞内钙信号的感知和解码。因此，这项研究提供了有关CNGC基因家族的信息，并深入了解了HvCNGC3和HvCNGC16在清克耐旱性中的功能和潜在的调控机制。
