Kryukov Vadim, Kosman Elena, Tomilova Oksana, Polenogova Olga, Rotskaya Ulyana, Yaroslavtseva Olga, Salimova Dilara, Kryukova Natalia, Berestetskiy Alexander
Institute of Systematics and Ecology of Animals, Siberian Branch of Russian Academy of Sciences, 630091, Frunze 11, Novosibirsk, Russia.
All-Russian Institute of Plant Protection, 196608, Podbel'skogo Sh. 3, Pushkin, St. Petersburg, Russia.
Mycotoxin Res. 2023 May;39(2):135-149. doi: 10.1007/s12550-023-00479-1. Epub 2023 Apr 18.
Tenuazonic acid (TeA) is synthesized by phytopathogenic and opportunistic fungi and is detected in a broad range of foods. This natural compound is of interest in terms of toxicity to animals, but its mechanisms of action on insects are poorly understood. We administered TeA orally at different concentrations (0.2-5.0 mg/[gram of a growth medium]) to the model insect Galleria mellonella, with subsequent estimation of physiological, histological, and immunological parameters in different tissues (midgut, fat body, and hemolymph). Susceptibility of the TeA-treated larvae to pathogenic microorganisms Beauveria bassiana and Bacillus thuringiensis was also analyzed. The feeding of TeA to the larvae led to a substation delay of larval growth, apoptosis-like changes in midgut cells, and an increase in midgut bacterial load. A decrease in activities of detoxification enzymes and downregulation of genes Nox, lysozyme, and cecropin in the midgut and/or hemocoel tissues were detected. By contrast, genes gloverin, gallerimycin, and galiomycin and phenoloxidase activity proved to be upregulated in the studied tissues. Hemocyte density did not change under the influence of TeA. TeA administration increased susceptibility of the larvae to B. bassiana but diminished their susceptibility to B. thuringiensis. The results indicate that TeA disturbs wax moth gut physiology and immunity and also exerts a systemic action on this insect. Mechanisms underlying the observed changes in wax moth susceptibility to the pathogens are discussed.
细交链孢菌酮酸（TeA）由植物病原真菌和机会性真菌合成，并在多种食品中被检测到。这种天然化合物因其对动物的毒性而受到关注，但其对昆虫的作用机制却知之甚少。我们以不同浓度（0.2 - 5.0毫克/[每克生长培养基]）给模式昆虫大蜡螟口服TeA，随后评估不同组织（中肠、脂肪体和血淋巴）中的生理、组织学和免疫学参数。还分析了经TeA处理的幼虫对病原微生物球孢白僵菌和苏云金芽孢杆菌的易感性。给幼虫喂食TeA导致幼虫生长出现替代延迟、中肠细胞出现凋亡样变化以及中肠细菌载量增加。检测到中肠和/或血腔组织中解毒酶活性降低以及Nox、溶菌酶和天蚕素基因的下调。相比之下，在所研究的组织中，gloverin、gallerimycin和galiomycin基因以及酚氧化酶活性被证明上调。血细胞密度在TeA的影响下没有变化。施用TeA增加了幼虫对球孢白僵菌的易感性，但降低了它们对苏云金芽孢杆菌的易感性。结果表明，TeA扰乱了大蜡螟肠道生理和免疫，并且对这种昆虫产生全身作用。本文讨论了观察到的大蜡螟对病原体易感性变化背后的机制。
