Co-Innovation Center for Sustainable Forestry in Southern China, State Key Laboratory of Tree Genetics and Breeding, College of Biology and the Environment, Nanjing Forestry University, Nanjing 210037, China.
Jiangsu Academy of Forestry, Nanjing 211153, China.
Int J Biol Macromol. 2023 Jul 1;242(Pt 4):125090. doi: 10.1016/j.ijbiomac.2023.125090. Epub 2023 May 27.
Poplar is one of the most widely used tree species in afforestation projects. CCR4 associated factor 1 (CAF1) is a major member of CCR4-NOT and plays an important role in eukaryotic mRNA deadenylation. However, its role in poplar remains unclear. In this study, the full-length cDNA of the PtCAF1I gene was cloned from the poplar by screening the highly expressed PtCAF1I gene in the identified PtCAF1 gene family by poplar sterilization. PtCAF1I was localized in the nucleus. Through sequence alignment, it was found that the PtCAF1I sequence contains three motifs and is highly similar to the CAF1 protein sequence of other species. In the quantitative expression analysis of tissues, the expression of PtCAF1I in different tissues of Populus trichocarpa, 'Nanlin895', and Shanxinyang was not much different. In addition, the analysis of the expression of the PtCAF1I gene under different stress treatments showed that PtCAF1I responded to abscisic acid (ABA), salicylic acid (SA), methyl jasmonate (MeJA), NaCl, PEG, hydrogen peroxide (HO) and cold stress to different degrees. To study the potential biological functions of PtCAF1I, 6 transgenic lines were obtained through transformation using an Agrobacterium tumefaciens infection system. The transcriptome sequencing results showed that DEGs were mainly concentrated in pathways of phenylpropanoid biosynthesis, biosynthesis of secondary metabolites, carbon metabolism, and carotenoid biosynthesis. Compared with WT poplar, the contents of cellulose, hemicellulose, lignin, total sugar, and flavonoids, and the cell wall thickness of PtCAF1I overexpression poplars were significantly higher. Under Septotinia populiperda treatment, transgenic poplars clearly exhibited certain disease resistance. Meanwhile, upregulation of the expression of JA and SA pathway-related genes also contributed to improving the disease tolerance of transgenic poplar. In conclusion, our results suggest that PtCAF1I plays an important role in the growth and development of poplars and their resistance to pathogens.
杨树是造林项目中应用最广泛的树种之一。CCR4 相关因子 1（CAF1）是 CCR4-NOT 的主要成员，在真核 mRNA 去腺苷酸化中发挥重要作用。然而，它在杨树中的作用尚不清楚。本研究通过筛选已鉴定的杨树 CAF1 基因家族中高表达的 PtCAF1I 基因，从杨树中克隆全长 cDNA 的 PtCAF1I 基因。PtCAF1I 定位于细胞核内。通过序列比对发现，PtCAF1I 序列含有三个基序，与其他物种的 CAF1 蛋白序列高度相似。在组织的定量表达分析中，PtCAF1I 在不同组织中的表达在‘Nanlin895’和山新杨的不同组织中差异不大。此外，对 PtCAF1I 基因在不同胁迫处理下的表达分析表明，PtCAF1I 对脱落酸（ABA）、水杨酸（SA）、茉莉酸甲酯（MeJA）、NaCl、PEG、过氧化氢（HO）和冷胁迫的响应程度不同。为了研究 PtCAF1I 的潜在生物学功能，通过农杆菌感染系统转化获得了 6 个转基因株系。转录组测序结果表明，差异表达基因主要集中在苯丙烷生物合成途径、次生代谢物生物合成途径、碳代谢途径和类胡萝卜素生物合成途径。与 WT 杨树相比，PtCAF1I 过表达杨树的纤维素、半纤维素、木质素、总糖和类黄酮含量以及细胞壁厚度明显更高。在 Septotinia populiperda 处理下，转基因杨树明显表现出一定的抗病性。同时，JA 和 SA 途径相关基因的表达上调也有助于提高转基因杨树的抗病性。综上所述，我们的研究结果表明 PtCAF1I 在杨树的生长发育及其对病原体的抗性中起着重要作用。
