Université de Reims Champagne-Ardenne, Unité de Recherche Résistance Induite et Bio-protection des Plantes, RIBP - EA 4707 - USC INRAE 1488, Moulin de la Housse-Bâtiment 18, BP 1039, 51687, Reims Cedex 2, France.
Sci Rep. 2021 Apr 15;11(1):8330. doi: 10.1038/s41598-021-87853-0.
Recognized as the causal agent of net blotch, Drechslera teres is responsible for major losses of barley crop yield. The consequences of this leaf disease are due to the impact of the infection on the photosynthetic performance of barley leaves. To limit the symptoms of this ascomycete, the use of beneficial bacteria known as "Plant Growth Promoting Rhizobacteria" constitutes an innovative and environmentally friendly strategy. A bacterium named as strain B25 belonging to the genus Burkholderia showed a strong antifungal activity against D. teres. The bacterium was able to limit the development of the fungus by 95% in detached leaves of bacterized plants compared to the non-bacterized control. In this study, in-depth analyses of the photosynthetic performance of young barley leaves infected with D. teres and/or in the presence of the strain B25 were carried out both in and close to the necrotic area. In addition, gas exchange measurements were performed only near the necrotic area. Our results showed that the presence of the beneficial bacterium reduced the negative impact of the fungus on the photosynthetic performance and modified only the net carbon assimilation rate close to the necrotic area. Indeed, the presence of the strain B25 decreased the quantum yield of regulated non-photochemical energy loss in PSII noted as Y(NPQ) and allowed to maintain the values stable of maximum quantum yield of PSII photochemistry known as F/F and close to those of the control in the presence of D. teres. To the best of our knowledge, these data constitute the first study focusing on the impact of net blotch fungus and a beneficial bacterium on photosynthesis and respiratory parameters in barley leaves.
被认为是网斑病的病原体，禾旋孢腔菌是大麦作物产量主要损失的原因。这种叶病的后果是由于感染对大麦叶片光合作用性能的影响。为了限制这种子囊菌的症状，使用被称为“植物生长促进根瘤菌”的有益细菌构成了一种创新和环保的策略。一种名为 B25 菌株的细菌属于伯克霍尔德氏菌属，对禾旋孢腔菌表现出很强的抗真菌活性。与未接种细菌的对照相比，在接种细菌的植物离体叶片中，细菌能够将真菌的发育抑制 95%。在这项研究中，对感染了禾旋孢腔菌和/或存在 B25 菌株的幼大麦叶片的光合作用性能进行了深入分析，无论是在坏死区域内还是附近。此外，仅在坏死区域附近进行了气体交换测量。我们的结果表明，有益细菌的存在减轻了真菌对光合作用性能的负面影响，并且仅在靠近坏死区域的地方改变了净碳同化率。事实上，B25 菌株的存在降低了 PSII 中调节非光化学能量损失的量子产量 Y(NPQ)，并在存在禾旋孢腔菌的情况下使 PSII 光化学的最大量子产量 F/F 及其附近的值保持稳定，接近对照值。据我们所知，这些数据构成了首次研究网斑病真菌和有益细菌对大麦叶片光合作用和呼吸参数的影响的研究。
