Zhou Wenlong, Du Jian, Jiao Runjie, Wang Xianbang, Fang Tiansong, Huang Guihua
Research Institute of Tropical Forestry, Chinese Academy of Forestry, Guangzhou, 520521, China.
The Forestry Development Service Center of Ganzhou City, Ganzhou, 341000, China.
BMC Plant Biol. 2025 Jan 10;25(1):35. doi: 10.1186/s12870-024-05788-w.
Calmodulin-binding transcription activator (CAMTA) proteins play significant roles in signal transduction, growth and development, as well as abiotic stress responses, in plants. Understanding their involvement in the low-temperature stress response of teak is vital for revealing cold resistance mechanisms.
Through bioinformatics analysis, the CAMTA gene family in teak was examined, and six CAMTA genes were identified in teak. The encoded proteins were predicted to be located in the nucleus and exhibited hydrophilic properties, with molecular weights ranging from 103.4 to 123.3 kDa and isoelectric points ranging from 5.49 to 7.55. On the basis of protein sequence homology, the CAMTA family could be divided into three subgroups. Domain and 3D structure analyses demonstrated that all the TgCAMTA proteins contained the typical CAMTA domain with the CaMBD binding domain, which was exposed on the surface. Expression analysis of different tissues revealed the expression of TgCAMTA genes in teak roots, stems, leaves, flowers, fruits, and branches. Furthermore, the promoter region contained various cis-acting elements related to light, hormone, and abiotic stress responses. After low-temperature stress treatment, different expression patterns of TgCAMTAs were observed in teak roots, stems, and leaves, with TgCAMTA1 showing the highest expression level in leaves compared with stems. Transgenic lines carrying the TgCAMTA1/3 promoter::GUS construct cold stress induction of TgCAMTA1/3 genes revealed the presence of multiple low-temperature responsive cis-acting elements in the TgCAMTA1/3 promoter region. Subcellular localization analysis indicated that these genes were functional predominantly in the nucleus. Compared with wild-type Arabidopsis, TgCAMTA1/3-overexpressing Arabidopsis presented increased tolerance to freezing stress, with increased expression of AtCOR genes. Moreover, under low-temperature conditions, TgCAMTA3-overexpressing Arabidopsis presented significantly elevated expression levels of genes related to the CBF signaling pathway, including AtCBF1/2/3.
Our findings add significantly to the existing knowledge regarding cold stress tolerance and help elucidate cold response mechanisms in teak.
钙调蛋白结合转录激活因子（CAMTA）蛋白在植物的信号转导、生长发育以及非生物胁迫响应中发挥着重要作用。了解它们在柚木低温胁迫响应中的作用对于揭示抗寒机制至关重要。
通过生物信息学分析，对柚木中的CAMTA基因家族进行了研究，在柚木中鉴定出6个CAMTA基因。预测编码的蛋白质定位于细胞核，具有亲水性，分子量范围为103.4至123.3 kDa，等电点范围为5.49至7.55。基于蛋白质序列同源性，CAMTA家族可分为三个亚组。结构域和三维结构分析表明，所有TgCAMTA蛋白都包含典型的带有CaMBD结合结构域的CAMTA结构域，该结构域暴露在表面。不同组织的表达分析揭示了TgCAMTA基因在柚木根、茎、叶、花、果实和枝条中的表达。此外，启动子区域包含各种与光、激素和非生物胁迫响应相关的顺式作用元件。低温胁迫处理后，在柚木根、茎和叶中观察到TgCAMTAs的不同表达模式，与茎相比，TgCAMTA1在叶中的表达水平最高。携带TgCAMTA1/3启动子::GUS构建体的转基因系对TgCAMTA1/3基因的冷胁迫诱导揭示了TgCAMTA1/3启动子区域中存在多个低温响应顺式作用元件。亚细胞定位分析表明这些基因主要在细胞核中发挥功能。与野生型拟南芥相比，过表达TgCAMTA1/3的拟南芥对冷冻胁迫的耐受性增强，AtCOR基因的表达增加。此外，在低温条件下，过表达TgCAMTA3的拟南芥中与CBF信号通路相关的基因，包括AtCBF1/2/3的表达水平显著升高。
我们的研究结果显著增加了关于冷胁迫耐受性的现有知识，并有助于阐明柚木的冷响应机制。
