Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM) - Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA/CSIC), Pozuelo de Alarcón (Madrid), Campus de Montegancedo UPM, Madrid, 28223, Spain.
Departamento de Biotecnología-Biología Vegetal, Escuela Técnica Superior de Ingeniería Agronómica, Alimentaría y de Biosistemas, UPM, Madrid, 28040, Spain.
Plant Mol Biol. 2023 Dec;113(6):401-414. doi: 10.1007/s11103-023-01345-5. Epub 2023 May 2.
Plant cell walls are complex structures mainly made up of carbohydrate and phenolic polymers. In addition to their structural roles, cell walls function as external barriers against pathogens and are also reservoirs of glycan structures that can be perceived by plant receptors, activating Pattern-Triggered Immunity (PTI). Since these PTI-active glycans are usually released upon plant cell wall degradation, they are classified as Damage Associated Molecular Patterns (DAMPs). Identification of DAMPs imply their extraction from plant cell walls by using multistep methodologies and hazardous chemicals. Subcritical water extraction (SWE) has been shown to be an environmentally sustainable alternative and a simplified methodology for the generation of glycan-enriched fractions from different cell wall sources, since it only involves the use of water. Starting from Equisetum arvense cell walls, we have explored two different SWE sequential extractions (isothermal at 160 ºC and using a ramp of temperature from 100 to 160 ºC) to obtain glycans-enriched fractions, and we have compared them with those generated with a standard chemical-based wall extraction. We obtained SWE fractions enriched in pectins that triggered PTI hallmarks in Arabidopsis thaliana such as calcium influxes, reactive oxygen species production, phosphorylation of mitogen activated protein kinases and overexpression of immune-related genes. Notably, application of selected SWE fractions to pepper plants enhanced their disease resistance against the fungal pathogen Sclerotinia sclerotiorum. These data support the potential of SWE technology in extracting PTI-active fractions from plant cell wall biomass containing DAMPs and the use of SWE fractions in sustainable crop production.
植物细胞壁是由碳水化合物和酚类聚合物组成的复杂结构。除了其结构功能外，细胞壁还作为抵御病原体的外部屏障，同时也是糖链结构的储存库，这些糖链结构可以被植物受体感知，从而激活模式触发免疫（PTI）。由于这些 PTI 活性糖链通常在植物细胞壁降解时释放，因此它们被归类为损伤相关分子模式（DAMPs）。DAMPs 的鉴定意味着它们可以通过使用多步方法和危险化学品从植物细胞壁中提取出来。亚临界水提取（SWE）已被证明是一种环境可持续的替代方法，也是一种从不同细胞壁来源生成富含聚糖的馏分的简化方法，因为它只涉及水的使用。我们从木贼细胞壁开始，探索了两种不同的 SWE 顺序提取（在 160°C 下等温提取和使用 100 至 160°C 的温度斜坡提取）以获得富含聚糖的馏分，并将其与基于化学的标准细胞壁提取生成的馏分进行了比较。我们获得了富含果胶的 SWE 馏分，这些果胶可触发拟南芥中的 PTI 特征，如钙离子内流、活性氧物质的产生、丝裂原活化蛋白激酶的磷酸化以及免疫相关基因的过表达。值得注意的是，将选定的 SWE 馏分应用于辣椒植物可增强其对真菌病原体核盘菌的抗病性。这些数据支持 SWE 技术从含有 DAMPs 的植物细胞壁生物质中提取 PTI 活性馏分的潜力，以及在可持续作物生产中使用 SWE 馏分的潜力。
