PDF(Pubmed)
Abstract：
Xylem sap proteomics provides crucial insights into plant defense and root-to-shoot communication. This study highlights the sensitivity and reproducibility of xylem sap proteome analyses, using a single plant per sample to track over 3000 proteins in two model crop plants, Solanum tuberosum and Hordeum vulgare. By analyzing the flg22 response, we identified immune response components not detectable through root or shoot analyses. Notably, we discovered previously unknown elements of the plant immune system, including calcium/calmodulin-dependent kinases and G-type lectin receptor kinases. Despite similarities in the metabolic pathways identified in the xylem sap of both plants, the flg22 response differed significantly: S. tuberosum exhibited 78 differentially abundant proteins, whereas H. vulgare had over 450. However, an evolutionarily conserved overlap in the flg22 response proteins was evident, particularly in the CAZymes and lipid metabolism pathways, where lipid transfer proteins and lipases showed a similar response to flg22. Additionally, many proteins without conserved signal sequences for extracellular targeting were found, such as members of the HSP70 family. Interestingly, the HSP70 response to flg22 was specific to the xylem sap proteome, suggesting a unique regulatory role in the extracellular space similar to that reported in mammalians.
摘要：
木质部树液蛋白质组学提供了对植物防御和根至芽通讯的重要见解。这项研究强调了木质部树液蛋白质组分析的敏感性和可重复性，每个样本使用单一植物来追踪两种模式作物植物中的3000多种蛋白质，马铃薯和大麦。通过分析flg22响应，我们确定了通过根或茎分析无法检测到的免疫反应成分。值得注意的是,我们发现了以前未知的植物免疫系统元素，包括钙/钙调蛋白依赖性激酶和G型凝集素受体激酶。尽管在两种植物的木质部汁液中发现的代谢途径相似，flg22反应差异显着：马铃薯表现出78种差异丰富的蛋白质，而H.vulgare超过450。然而,在flg22反应蛋白的进化保守的重叠是明显的，特别是在CAZymes和脂质代谢途径中，其中脂质转移蛋白和脂肪酶显示出与flg22相似的反应。此外,许多蛋白质没有保守的信号序列的细胞外靶向被发现，例如HSP70家族的成员。有趣的是,HSP70对flg22的响应是木质部树液蛋白质组特有的，表明在细胞外空间中具有独特的调节作用，类似于哺乳动物中报道的作用。
