Chen Canni, Xiao Huiping, Yue Jiao, Wang Xu, Wang Caijin, Wei Rujian, Luo Dengjie, Chen Peng
College of Agriculture, Guangxi University, Key Laboratory of Crop Genetic Breeding and Germplasm Innovation, Guangxi Key Laboratory of Agro-Environment and Agric-Products Safety, 530004, Nanning, China.
Mol Genet Genomics. 2025 Jun 28;300(1):65. doi: 10.1007/s00438-025-02272-4.
Cyclic Nucleotide-Gated Channel (CNGC) gene consists a large family and plays an important role in plant growth and development, biotic and abiotic stresses, yet their functions in non-model crops like kenaf (Hibiscus cannabinus L.), a highly stress-resistant bast fiber crop, remain poorly understood. To investigate the role in kenaf abiotic stress response and plant development regulation, we characterized the HcCNGC27 gene in kenaf. Our study aimed to elucidate the role of HcCNGC27 in drought stress response and its impact on plant development. HcCNGC27 was identified subcellularly localized to the plasma membrane. Expression analysis showed that HcCNGC27 is ubiquitously expressed across various tissues including roots, stems, leaves, flowers, and seeds, with the highest expression observed in flowers. Importantly, HcCNGC27 was significantly induced under drought stress conditions. To investigate the function of HcCNGC27, we performed virus-induced gene silencing (VIGS) in kenaf and overexpression in Arabidopsis thaliana. Silencing of HcCNGC27 in kenaf resulted in a dwarf phenotype and reduced drought stress tolerance, evidenced by decreased antioxidant enzyme activities, increased reactive oxygen species (ROS) accumulation, and decreased osmoregulatory substances content. Additionally, the expression levels of antioxidant enzyme-related genes and stress-responsive genes were markedly down-regulated in the silenced lines. Conversely, overexpression of HcCNGC27 in Arabidopsis thaliana enhanced drought stress tolerance, characterized by stronger protective enzyme activity, better ROS scavenging capacity, improved osmotic adjustment, higher total chlorophyll content, lower death rate, and significant up-regulation of stress-responsive genes. Moreover, overexpression of HcCNGC27 delayed flowering in Arabidopsis thaliana, as indicated by qRT-PCR analysis showing significant down-regulation of AtFT and AtSOC1 and up-regulation of AtFLC in the overexpression lines compared to wild-type controls. In summary, HcCNGC27 emerges as a dual-function regulator enhancing drought tolerance via ROS scavenging and osmotic adjustment while delaying flowering may through modulation of the FT/SOC1/FLC pathway.
环核苷酸门控通道（CNGC）基因构成一个大家族，在植物生长发育、生物和非生物胁迫中发挥重要作用，然而它们在红麻（Hibiscus cannabinus L.）等非模式作物中的功能仍知之甚少，红麻是一种高度抗逆的韧皮纤维作物。为了研究其在红麻非生物胁迫响应和植物发育调控中的作用，我们对红麻中的HcCNGC27基因进行了表征。我们的研究旨在阐明HcCNGC27在干旱胁迫响应中的作用及其对植物发育的影响。HcCNGC27被鉴定为亚细胞定位于质膜。表达分析表明，HcCNGC27在包括根、茎、叶、花和种子在内的各种组织中普遍表达，在花中表达最高。重要的是，HcCNGC27在干旱胁迫条件下被显著诱导。为了研究HcCNGC27的功能，我们在红麻中进行了病毒诱导的基因沉默（VIGS），并在拟南芥中进行了过表达。红麻中HcCNGC27的沉默导致矮化表型并降低了干旱胁迫耐受性，抗氧化酶活性降低、活性氧（ROS）积累增加和渗透调节物质含量降低证明了这一点。此外，沉默株系中抗氧化酶相关基因和胁迫响应基因的表达水平明显下调。相反，HcCNGC27在拟南芥中的过表达增强了干旱胁迫耐受性，其特征是保护酶活性更强、ROS清除能力更好、渗透调节改善、总叶绿素含量更高、死亡率更低以及胁迫响应基因显著上调。此外，HcCNGC27在拟南芥中的过表达延迟了开花，qRT-PCR分析表明，与野生型对照相比，过表达株系中AtFT和AtSOC1显著下调，AtFLC上调。总之，HcCNGC27是一种双功能调节因子，通过ROS清除和渗透调节增强耐旱性，并可能通过调节FT/SOC1/FLC途径延迟开花。
