RESULTS: The cucumber genome encompassed 16 SPX domain-containing genes, which were distributed across six chromosomes and categorized into four distinct subfamilies: SPX, SPX-MFS, SPX-EXS and SPX-RING, based on their structure characteristics. Additionally, gene duplications and synteny analysis were conducted for CsSPXs, revealing that their promoter regions were enriched with a variety of hormone-responsive, biotic/abiotic stress and typical P1BS-related elements. Tissue expression profiling of CsSPX genes revealed that certain members were specifically expressed in particular organs, suggesting essential roles in cucumber growth and development. Under low Pi stress, CsSPX1 and CsSPX2 exhibited a particularly strong response to Pi starvation. It was observed that the cucumber cultivar Xintaimici displayed greater tolerance to low Pi compared to black-spined cucumber under low Pi stress conditions. Protein interaction networks for the 16 CsSPX proteins were predicted, and yeast two-hybrid assay revealed that CsPHR1 interacted with CsSPX2, CsSPX3, CsSPX4 and CsSPX5, implying their involvement in the Pi signaling pathway in conjunction with CsPHR1.
CONCLUSIONS: This research lays the foundation for further exploration of the function of the CsSPX genes in response to low Pi stress and for elucidating the underlying mechanism.
结果:黄瓜基因组包含16个含SPX结构域的基因,它们分布在六个染色体上,分为四个不同的亚家族:SPX,SPX-MFS,SPX-EXS和SPX-RING,基于它们的结构特征。此外,对CsSPXs进行了基因重复和同构分析,揭示它们的启动子区域富含多种激素反应,生物/非生物胁迫和典型的P1BS相关元素。CsSPX基因的组织表达谱显示,某些成员在特定器官中特异性表达,提示在黄瓜生长发育中的重要作用。在低Pi压力下,CsSPX1和CsSPX2对Pi饥饿表现出特别强的响应。观察到,在低Pi胁迫条件下,与黑刺黄瓜相比,黄瓜品种Xintaimici对低Pi表现出更高的耐受性。预测了16种CsSPX蛋白的蛋白相互作用网络,和酵母双杂交分析显示,CsPHR1与CsSPX2,CsSPX3,CsSPX4和CsSPX5相互作用,表明它们与CsPHR1一起参与Pi信号通路。
结论:本研究为进一步探索CsSPX基因在低Pi胁迫下的功能以及阐明其潜在机制奠定了基础。