为阐明紫穗槐（Amorpha fruticosa Linn.）SKP2A基因对激素和逆境信号的响应及其在叶绿素合成中的作用，克隆获得AfSKP2A（GenBank登录号ON045086），采用生物信息学方法分析其编码蛋白特性，检测该基因的组织表达特性及响应激素和胁迫的表达特性；构建过表达AfSKP2A山新杨（Populus davidiana × bolleana）株系，综合分析其叶色变化及相关生理指标。结果表明：AfSKP2A基因编码蛋白的氨基酸残基数为374，为稳定的疏水性蛋白，含典型的F-box结构域及8个LRR结构域。该蛋白与白羽扇豆（Lupinus albus Linn.）SKP2A-like蛋白亲缘关系最近，且与另11种植物SKP2蛋白N端F-box的氨基酸序列一致性较高。基因表达分析结果显示：AfSKP2A在根、穗、叶、花中高表达，且在叶中的表达量受吲哚乙酸、脱落酸、水杨酸及NaCl和干旱胁迫强烈诱导。在线预测及瞬时表达实验均证实AfSKP2A蛋白定位于细胞质。过表达AfSKP2A山新杨株系叶片褪绿呈现紫斑，伴随叶绿素含量降低，光系统Ⅱ最大光化学效率（Fv/Fm）下降，同时抗氧化酶基因PdAPX和PdSOD及糖酵解途径关键酶基因PdENO的表达显著上调。综上所述，AfSKP2A可能通过响应多种激素与非生物胁迫参与叶绿素代谢调控，并经由泛素化途径影响叶绿体功能。

  To clarify the response of SKP2A gene of Amorpha fruticosa Linn. to hormone and stress signals and its role in chlorophyll synthesis, AfSKP2A (GenBank accession number ON045086) was cloned, the protein characteristics encoded by this gene were analyzed by using bioinformatics methods, and the tissue expression characteristics as well as expression characteristics in response to hormones and stresses were detected; AfSKP2A-overexpression lines of Populus davidiana × bolleana were constructed, and their leaf color variations and related physiological indexes were comprehensively analyzed. The results show that the amino acid residue number of protein encoded by AfSKP2A gene is 374, it is a stable hydrophobic protein, and contains a typical F-box domain and eight LRR domains. This protein is most closely related with SKP2A-like protein of Lupinus albus Linn., and has relatively high identities of amino acid sequence in the N-terminal F-box with SKP2 proteins of other 11 plant species. The gene expression analysis result reveals that AfSKP2A is highly expressed in roots, spikes, leaves, and flowers, and its expression in leaves is strongly induced by indoleacetic acid, abscisic acid, salicylic acid, as well as NaCl and drought stresses. The online prediction and transient expression experiments both confirm that AfSKP2A protein is localized in the cytoplasm. AfSKP2A-overexpression lines of P. davidiana × bolleana exhibit chlorotic leaves with purple spots, accompanied by reduced chlorophyll content, decreased maximum photochemical efficiency of photosystem Ⅱ (Fv/Fm), meanwhile significantly upregulated antioxidant enzyme genes PdAPX and PdSOD and a   glycolytic pathway key enzyme gene PdENO. In conclusion, AfSKP2A may participate in the regulation of chlorophyll metabolism by responding to multiple hormones and abiotic stresses, and may affect chloroplast function through the ubiquitination pathway.