Kopecká Romana, Černý Martin
Department of Molecular Biology and Radiobiology, Faculty of AgriSciences, Mendel University in Brno, 61300 Brno, Czech Republic.
Plants (Basel). 2024 Jul 20;13(14):1983. doi: 10.3390/plants13141983.
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, and . 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: exhibited 78 differentially abundant proteins, whereas 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.
木质部汁液蛋白质组学为植物防御和根到茎的信号传递提供了关键见解。本研究强调了木质部汁液蛋白质组分析的灵敏度和可重复性，每个样本使用一株植物来追踪两种模式作物中的3000多种蛋白质。通过分析flg22反应，我们鉴定出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，我们发现了植物免疫系统中以前未知的成分，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鉴定出的代谢途径存在相似性，但flg22反应却有显著差异：[植物名称1]表现出78种差异丰富的蛋白质，而[植物名称2]有超过450种。然而，flg22反应蛋白中存在明显的进化保守重叠，特别是在碳水化合物活性酶（CAZymes）和脂质代谢途径中，脂质转运蛋白和脂肪酶对flg22表现出相似的反应。此外，还发现了许多没有用于细胞外靶向的保守信号序列的蛋白质，如HSP70家族成员。有趣的是，HSP70对flg22的反应在木质部汁液蛋白质组中是特异性的，这表明其在细胞外空间中具有类似于哺乳动物中报道的独特调节作用。
