Université de Poitiers, Ecologie & Biologie des Interactions, UMR CNRS 7267, 1 rue Georges Bonnet, TSA51106, 86073 Poitiers cedex 9, France.
Université de Poitiers, Ecologie & Biologie des Interactions, UMR CNRS 7267, 1 rue Georges Bonnet, TSA51106, 86073 Poitiers cedex 9, France; Current address: Sorbonne Universités, Université de Technologie de Compiègne, UMR CNRS 7025, Génie Enzymatique et Cellulaire, Rue du Docteur Schweitzer CS 60319, 60203 Compiègne Cedex, France.
Plant Physiol Biochem. 2018 Aug;129:77-89. doi: 10.1016/j.plaphy.2018.05.024. Epub 2018 May 23.
Early effects induced by cysteine were monitored using the model of Mimosa pudica pulvinar cells. Rapid dose-dependent membrane depolarization (within seconds) and modification of proton secretion (within minutes) were triggered at cysteine concentrations higher than 0.1 mM. These effects did not result from a modification of the plasma membrane H-ATPase activity nor from a protonophore effect as shown by assays on plasma membrane vesicles isolated from pulvinar tissues. In a 0.5-10 mM range, cysteine inhibited the ion-driven turgor-mediated seismonastic reaction of Mimosa pudica primary pulvini and the dark-induced movement of Cassia fasciculata leaflets. At concentrations higher than 1 mM, it induced a long-lasting leaflet necrosis dependent on the concentration and treatment duration. Electron microscopy showed that cysteine induced important damage in the nucleus, mitochondria, endoplasmic reticulum and Golgi of the M. pudica motor cell. Cysteine inhibited in a concentration-dependent manner, from 0.5 to 20 mM, both the mycelial growth and the spore germination of the fungal pathogens Phaeomoniella chlamydospora and Phaeoacremonium minimum implicated in esca disease of grapevines. Using [S] cysteine, we showed that the amino acid was absorbed following leaf spraying, translocated from leaves to other parts of grapevine cuttings and accumulated within trunks and roots. Therefore, cysteine showed relevant properties to be a candidate able to control fungal diseases either by acting as an early signal directing plant host reaction or/and by acting directly on fungal development.
采用含羞草叶褥细胞模型监测半胱氨酸诱导的早期效应。在半胱氨酸浓度高于 0.1mM 时，会引发快速的、剂量依赖性的膜去极化（在数秒内）和质子分泌的改变（在数分钟内）。这些效应不是由质膜 H+-ATP 酶活性的改变或质子载体效应引起的，因为这两种效应可以通过对叶褥组织分离的质膜小泡进行检测得以证实。在 0.5-10mM 范围内，半胱氨酸抑制了离子驱动的膨压介导的含羞草初生根褥叶的地震性弯曲反应和决明子小叶的暗诱导运动。在高于 1mM 的浓度下，它会导致小叶坏死，其依赖于浓度和处理时间的长短。电子显微镜显示，半胱氨酸诱导含羞草运动细胞的细胞核、线粒体、内质网和高尔基体受到严重损伤。半胱氨酸以浓度依赖性的方式抑制真菌病原体 Phaeomoniella chlamydospora 和 Phaeoacremonium minimum 的菌丝生长和孢子萌发，其抑制作用在 0.5 到 20mM 之间。这两种真菌病原体都与葡萄藤 esca 病有关。使用 [S]半胱氨酸，我们表明该氨基酸在叶面上喷洒后被吸收，从叶片转运到葡萄插条的其他部位，并在树干和根部积累。因此，半胱氨酸具有相关特性，可作为候选物来控制真菌病害，要么作为早期信号来指导植物宿主反应，要么直接作用于真菌发育。
