Gramegna Giovanna, Modesti Vanessa, Savatin Daniel V, Sicilia Francesca, Cervone Felice, De Lorenzo Giulia
Istituto Pasteur-Cenci Bolognetti, Dipartimento di Biologia e Biotecnologie 'C. Darwin', Sapienza Università di Roma, Piazzale Aldo Moro 5, 00185 Rome, Italy.
Istituto Pasteur-Cenci Bolognetti, Dipartimento di Biologia e Biotecnologie 'C. Darwin', Sapienza Università di Roma, Piazzale Aldo Moro 5, 00185 Rome, Italy
J Exp Bot. 2016 Mar;67(6):1715-29. doi: 10.1093/jxb/erv563. Epub 2016 Jan 8.
Conserved microbe-associated molecular patterns (MAMPs) and damage-associated molecular patterns (DAMPs) act as danger signals to activate the plant immune response. These molecules are recognized by surface receptors that are referred to as pattern recognition receptors. Oligogalacturonides (OGs), DAMPs released from the plant cell wall homogalacturonan, have also been proposed to act as local signals in the response to wounding. The Arabidopsis Wall-Associated Kinase 1 (WAK1), a receptor of OGs, has been described to form a complex with a cytoplasmic plasma membrane-localized kinase-associated protein phosphatase (KAPP) and a glycine-rich protein (GRP-3) that we find localized mainly in the cell wall and, in a small part, on the plasma membrane. By using Arabidopsis plants overexpressing WAK1, and both grp-3 and kapp null insertional mutant and overexpressing plants, we demonstrate a positive function of WAK1 and a negative function of GRP-3 and KAPP in the OG-triggered expression of defence genes and the production of an oxidative burst. The three proteins also affect the local response to wounding and the basal resistance against the necrotrophic pathogen Botrytis cinerea. GRP-3 and KAPP are likely to function in the phasing out of the plant immune response.
保守的微生物相关分子模式（MAMPs）和损伤相关分子模式（DAMPs）作为危险信号激活植物免疫反应。这些分子被称为模式识别受体的表面受体所识别。寡聚半乳糖醛酸（OGs）是从植物细胞壁同型半乳糖醛酸释放的DAMPs，也被认为在对伤口的反应中作为局部信号起作用。拟南芥细胞壁相关激酶1（WAK1）是OGs的一种受体，已被描述为与一种定位于细胞质质膜的激酶相关蛋白磷酸酶（KAPP）和一种富含甘氨酸的蛋白（GRP-3）形成复合物，我们发现GRP-3主要定位于细胞壁，小部分定位于质膜。通过使用过表达WAK1的拟南芥植株，以及grp-3和kapp缺失插入突变体和过表达植株，我们证明了WAK1在OG触发的防御基因表达和氧化爆发产生中的正向作用，以及GRP-3和KAPP的负向作用。这三种蛋白还影响对伤口的局部反应和对坏死营养型病原菌灰葡萄孢的基础抗性。GRP-3和KAPP可能在植物免疫反应的逐步减弱中发挥作用。
