UCEIV, GIS PhyNoPi, Université du Littoral Côte d'Opale, Calais, France.
Plant Biol (Stuttg). 2012 Mar;14 Suppl 1:11-21. doi: 10.1111/j.1438-8677.2011.00443.x. Epub 2011 Feb 11.
This study investigated the infection process of Mycosphaerella graminicola and enzyme activities related to reactive oxygen species (ROS) or oxylipin biosynthesis in four French wheat cultivars with variable resistance to M. graminicola infection. At field level, cultivars Caphorn, Maxyl and Gen11 were susceptible, whereas Capnor showed high levels of quantitative resistance. Moreover, Capnor and Gen11 were tolerant, i.e., their yield was less affected by infection compared to non-tolerant Maxyl and Caphorn. These four cultivars were inoculated under laboratory conditions with the M. graminicola IPO323 reference strain. Cytological and biochemical responses were studied on collected first plantlet leaves and several features discriminated between cultivars. However, resistance and tolerance had no impact on the fungal infection process. Levels of lipoxygenase (LOX), peroxidase (PO) and glutathione-S-transferase (GST) activities were also compared with regard to cultivar resistance or tolerance to M. graminicola. LOX, PO and GST activities did not discriminate resistance and tolerance profiles, although a low level of PO in inoculated and non-inoculated plants could be associated with tolerance. In addition, cell necrosis correlated positively with LOX in non-tolerant cultivars, while mycelia surrounding stomata were positively correlated with PO in the resistant cultivar. GST activity presented correlations between cytological and biochemical parameters only for susceptible cultivars. Stomatal and direct penetration were positively correlated with GST activity in the susceptible non-tolerant cultivars, while these correlations were negative in the tolerant cultivar. When combining cytological and biochemical observations with resistance and tolerance profiles, for each cultivar and at each time point, cultivars could be classified in tight accordance with their previous field characterisation. Moreover, tolerance allowed us to distinguish susceptible cultivars when both biochemical and cytological parameters were considered together.
本研究调查了麦类球腔菌（Mycosphaerella graminicola）在四个法国小麦品种中的感染过程，这些品种对麦类球腔菌感染的抗性不同，分为易感性、高量抗性和耐性。在田间水平，品种 Caphorn、Maxyl 和 Gen11 为易感性，而 Capnor 则表现出高水平的定量抗性。此外，Caphorn 和 Gen11 为耐性品种，即与非耐性品种 Maxyl 和 Caphorn 相比，它们的产量受感染的影响较小。这四个品种在实验室条件下用麦类球腔菌 IPO323 参考菌株进行接种。在收集的第一片幼苗叶片上研究了细胞学和生物化学反应，并对品种之间的几个特征进行了区分。然而，抗性和耐性对真菌感染过程没有影响。还比较了脂氧合酶（LOX）、过氧化物酶（PO）和谷胱甘肽-S-转移酶（GST）的活性，以研究它们与麦类球腔菌抗性或耐性的关系。LOX、PO 和 GST 活性不能区分抗性和耐性谱，尽管接种和未接种植物中的 PO 水平低可能与耐性有关。此外，细胞坏死与非耐性品种中的 LOX 呈正相关，而围绕气孔的菌丝与抗性品种中的 PO 呈正相关。GST 活性仅在易感性品种中与细胞学和生物化学参数之间存在相关性。气孔和直接穿透与易感性非耐性品种中的 GST 活性呈正相关，而在耐性品种中则呈负相关。当将细胞学和生物化学观察与抗性和耐性谱相结合，并针对每个品种和每个时间点进行分析时，每个品种都可以根据其先前的田间特征进行紧密分类。此外，当同时考虑生化和细胞学参数时，耐性可以区分易感性品种。
