We present changes in Tacitus bellus antioxidative system that specifically correspond to subsequent phases of hemibiotroph Fusarium verticillioides infection revealed by histological analysis. T. bellus response to spore germination 6 h post inoculation (hpi), manifested as first oxidative burst, was characterized by transient decrease in malondialdehyde (MDA) content, transient increase in catalase (CAT), low level of superoxide dismutase (SOD) and peroxidase (POD) activity, as well as with transient decrease in total antioxidant capacity (TAC), total phenol content (TPC) and phenylalanine ammonium lyase activity (PAL), and no changes in polyphenol oxidase (PPO) activity, or phenolic profile. During the biotrophic phase of F. verticillioides infection, characterized by hyphae spread intercellularly in epidermal and mesophyll tissue, the host antioxidative system was suppressed. The transition to necrotrophic phase of F. verticillioides infection (inter- and intracellular colonization and sporulation), occurred 3-4 days post inoculation (dpi). During the necrotrophic phase, 5-7 dpi, slowed progression of colonization of T. bellus mesophyll cells occurred and it coincided with sharp increase in MDA content and CAT, SOD and POD activities, but the drop in TAC, TPC content, and PPO activity, as well as the production of phytotoxin fusaric acid. Presented results add to the knowledge of events and mechanisms related to the transition from biotrophy to necrotrophy in F. verticillioides.

中文翻译：

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多肉植物 Tacitus bellus 体外对轮枝镰孢感染的生化和组织学表征

我们提出了 Tacitus bellus 抗氧化系统的变化，这些变化特别对应于组织学分析显示的半生物镰刀菌感染的后续阶段。T. bellus 在接种 (hpi) 后 6 小时对孢子萌发的反应，表现为第一次氧化爆发，其特征是丙二醛 (MDA) 含量瞬时减少、过氧化氢酶 (CAT) 瞬时增加、超氧化物歧化酶 (SOD) 水平低和过氧化物酶 (POD) 活性，以及​​总抗氧化能力 (TAC)、总酚含量 (TPC) 和苯丙氨酸铵裂解酶活性 (PAL) 的短暂下降，并且多酚氧化酶 (PPO) 活性或酚类成分没有变化。F. verticillioides 感染的生物营养阶段，其特征是菌丝在表皮和叶肉组织的细胞间扩散，宿主抗氧化系统受到抑制。F. verticillioides 感染（细胞间和细胞内定植和孢子形成）转变为坏死营养阶段，发生在接种后 3-4 天 (dpi)。在坏死性营养阶段，5-7 dpi，T. bellus 叶肉细胞定植进程减慢，同时MDA含量和CAT、SOD和POD活性急剧增加，但TAC、TPC含量和PPO活性下降，以及植物毒素镰刀酸的生产。所呈现的结果增加了与轮枝菌从生物营养向坏死营养过渡相关的事件和机制的知识。发生在接种后 3-4 天 (dpi)。在坏死性营养阶段，5-7 dpi，T. bellus 叶肉细胞定植进程减慢，同时MDA含量和CAT、SOD和POD活性急剧增加，但TAC、TPC含量和PPO活性下降，以及植物毒素镰刀酸的生产。所呈现的结果增加了与轮枝菌从生物营养向坏死营养过渡相关的事件和机制的知识。发生在接种后 3-4 天 (dpi)。在坏死性营养阶段，5-7 dpi，T. bellus 叶肉细胞定植进程减慢，同时MDA含量和CAT、SOD和POD活性急剧增加，但TAC、TPC含量和PPO活性下降，以及植物毒素镰刀酸的生产。所呈现的结果增加了与轮枝菌从生物营养向坏死营养过渡相关的事件和机制的知识。