Hyon Gang-Su, Ikeda Ken-Ichi, Hosogi Naoki, Shinogi Takeshi, Park Pyoyun
Laboratory of Stress Cytology, Graduate School of Agricultural Science, Kobe University , Rokkodai, Nada, Kobe, Japan.
Phytopathology. 2010 Sep;100(9):840-7. doi: 10.1094/PHYTO-100-9-0840.
In the Japanese pear pathotype of Alternaria alternata, H2O2 is generated solely from penetration pegs and not from other portions of subcuticular hyphae within the pectin layers of host leaves. A close association between H2O2 generation and fungal aggressiveness is expected because the pegs are important for fungal penetration into the host epidermis. To determine the potential role of reactive oxygen species in microbial pathogenicity, we studied the inhibitory effects of the antioxidant reagent ascorbic acid and the NADPH oxidase inhibitor diphenylene iodonium on infection of the pathogen. In our study, we showed H2O2 generation to be inhibited by inoculation with the mixture of ascorbic acid or diphenylene iodonium and spores at the pegs in the spore-inoculated host leaves. The decrease of generation in the pegs resulted in penetration failure, indicating that H2O2 generation probably contributed to strengthening of the penetration and probably was recruited by NADPH oxidase.
在日本梨链格孢菌致病型中，过氧化氢仅由侵入栓产生，而非来自寄主叶片果胶层内皮下菌丝的其他部分。由于侵入栓对于真菌穿透寄主表皮很重要，因此预计过氧化氢的产生与真菌侵袭力之间存在密切关联。为了确定活性氧在微生物致病性中的潜在作用，我们研究了抗氧化剂试剂抗坏血酸和NADPH氧化酶抑制剂二苯基碘鎓对病原体感染的抑制作用。在我们的研究中，我们发现，在接种孢子的寄主叶片的侵入栓处，用抗坏血酸或二苯基碘鎓与孢子的混合物接种可抑制过氧化氢的产生。侵入栓处过氧化氢产生的减少导致穿透失败，这表明过氧化氢的产生可能有助于增强穿透能力，并且可能是由NADPH氧化酶募集的。
