| 摘要: |
| 【 目的】鉴定灰杨（Populus×canescens）铜转运蛋白（PcCOPT）家族成员，明确PcCOPTs基因响应Cd胁迫的表达模式。【 方法】以灰杨（Populus×canescens）为试验材料，利用生物信息学方法对PcCOPT家族成员进行鉴定、蛋白质序列特征分析、亚细胞定位预测、系统发育分析、共线性分析及顺式作用元件分析；使用MEGA11构建系统进化树；使用TBtools对PcCOPT家族成员的基因结构、保守基序、染色体定位、共线性等进行可视化分析；通过RT-qPCR技术分析PcCOPT家族成员的组织表达模式以及响应Cd胁迫的表达特征。【 结果】从灰杨基因组中共鉴定出7个无内含子的COPT基因，分布在1，6和9号染色体上。蛋白质序列特征分析结果表明，编码PcCOPT家族蛋白的氨基酸序列长度为141~159个氨基酸，相对分子质量为15.73-17.64，理论等电点为6.15-9.99。亚细胞定位预测结果表明，PcCOPT1、PcCOPT2、PcCOPT3、PcCOPT6和PcCOPT7定位在细胞质膜上，PcCOPT4和PcCOPT5定位在液泡膜上。系统发育分析显示，PcCOPT家族分为3个进化分支，其中第一分支包含PcCOPT1，PcCOPT6和PcCOPT7，第二分支包含PcCOPT2和PcCOPT3，第三分支包含PcCOPT4和PcCOPT5。共线性分析结果显示，在灰杨基因组内有2对共线性基因，灰杨与拟南芥之间有6对共线性基因，灰杨与水稻之间有4对共线性基因。顺式作用元件分析结果表明，PcCOPTs基因启动子区包含多个光响应、激素应答和非生物胁迫响应元件。PcCOPTs基因表达具有组织特异性，其中PcCOPT2、PcCOPT3在根中高度表达，PcCOPT1在木质部特异性表达，PcCOPT4、PcCOPT6和PcCOPT7在幼叶中表达水平较高，PcCOPT5在根和木质部中表达水平较高。与对照相比，在Cd胁迫下，第一分支成员PcCOPT1、PcCOPT6和PcCOPT7表达量显著升高；第二分支PcCOPT2和PcCOPT3在Cd胁迫72 h后表达量显著降低；第三分支成员PcCOPT5表达量升高，但PcCOPT4表达量显著降低。【 结论】从灰杨基因组中共鉴定出7个PcCOPT基因，分为3个分支。其中第一分支成员PcCOPT1、PcCOPT6和PcCOPT7的表达受Cd胁迫诱导表达，第二分支成员PcCOPT2和PcCOPT3的表达受Cd胁迫抑制，第三分支成员PcCOPT4和PcCOPT5在Cd胁迫下表达量变化趋势相反。表明PcCOPTs成员可能具有功能分化，在灰杨响应Cd胁迫过程中发挥不同作用。 |
| 关键词: 灰杨 COPT基因家族 基因表达 Cd 胁迫 |
| DOI：10. 13207/j. jnwafu. 2026. 11. 004 |
| 分类号: |
| 基金项目:国家自然科学基金项目（32371841） |
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| Identification of COPT protein family members in Populus×canescens and expression analysis under cadmium stress |
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CHENG Yao1, DENG Shurong1, LUO Zhibin1,2,3
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1.State Key Laboratory of Tree Genetics and Breeding，Research Institute of Forestry，Chinese Academy of Forestry，Beijing 100091，China;2.Institute of Ecological Protection and Restoration，Chinese Academy of Forestry，Beijing 100091，China;3.Comprehensive Experimental Center of Chinese Academy of Forestry in Yellow River Delta，Dongying，Shandong 257000，China
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| Abstract: |
| 【 Objective】The study aims to identify the COPT family members in Populus×canescens and clarify the expression patterns of PcCOPT genes in response to cadmium（Cd） stress.【Method】Using Populus×canescens as materials，bioinformatic approaches were used to identify the members of the PcCOPT family，analyze the characteristics of protein sequences，predict the subcellular localization，and conduct phylogenetic analysis，collinearity analysis，and cis-acting element analysis.MAGE11 was used to construct a phylogenetic tree. The gene structures，conserved motifs，chromosome locations，and collinearity of PcCOPT family members were visualized using TBtools. Reverse transcription-quantitative PCR was carried out to analyze the tissue-specific expression patterns of PcCOPT family members and their expression characteristics in response to Cd exposure.【Result】Seven putative intron-lacking PcCOPT genes were identified in the genome of Populus×canescens，located on chromosome 1，6 and 9. Protein sequence analysis showed that the encoded PcCOPT family proteins consisted of 141-159 amino acid residues，with relative molecular weights ranging from 15.73 to 17 64 and the theoretical isoelectric point between 6.15 and 9.99. The prediction of subcellular localizations showed that PcCOPT1，PcCOPT2，PcCOPT3，PcCOPT6 and PcCOPT7 were located on the plasma mem?brane，while PcCOPT4 and PcCOPT5 were located on the vacuole membrane. The phylogenetic analysis exhibi-ted that the PcCOPT family members were divided into three clades. The first clade included PcCOPT1，PcCOPT6，and PcCOPT7，the second clade included PcCOPT2 and PcCOPT3，and the third clade included PcCOPT4 and PcCOPT5. Collinearity analysis showed that there were two pairs of collinear genes within the Populus×canescens genome，six pairs of collinear genes between the genomes of Populus×canescens and Arabidopsis thaliana，and four pairs of collinear genes between the genomes of Populus×canescens and Oryza sativa. Cis-acting element analysis revealed that the promoters of PcCOPTs genes contained multiple regulatory elements related to light，hormone or abiotic stress response. RT-qPCR analysis revealed tissue-specific expression patterns among PcCOPT genes.PcCOPT2 and PcCOPT3 were highly expressed in the roots of P.×canescens，PcCOPT1 was relatively highly expressed in xylem，PcCOPT4，PcCOPT6 and PcCOPT7 exhibited high ex-pression levels in the young leaves，and PcCOPT5 were expressed at relatively high levels in roots and xylem. Under cadmium（Cd） stress，the expression levels of PcCOPT1，PcCOPT6 and PcCOPT7 in the first clade were markedly upregulated. In contrast，the transcript levels of PcCOPT2 and PcCOPT3 in the second clade were obviously decreased after 72 h of Cd treatment.In the third clade，the mRNA level of PcCOPT5 was increased，while that of PcCOPT4 was significantly decreased upon Cd exposure.【Conclusion】This study identified seven PcCOPTs in Populus×canescens，which were divided into three clades.Under Cd stress，PcCOPT1，PcCOPT6 and PcCOPT7 in the first clade were induced，PcCOPT2 and PcCOPT3 in the second clade were repressed，and PcCOPT4 and PcCOPT5 of the third clade showed opposite trends. These results demonstrated that different PcCOPTs may have functional differentiation and play different roles in mediating Cd response. |
| Key words: Populus×canescens COPT gene family gene expression cadmium stress |
