Comparative analysis of immune responses in Colorado potato beetle larvae during development of mycoses caused by Metarhizium robertsii, M. brunneum, and M. pemphigi

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• 作者：M. V. Tyurin ; V. Yu. Kryukov…
• 刊名：Journal of Evolutionary Biochemistry and Physiology
• 出版年：2016
• 出版时间：May 2016
• 年：2016
• 卷：52
• 期：3
• 页码：252-260
• 全文大小：218 KB
• 刊物类别：Biomedical and Life Sciences
• 刊物主题：Life Sciences
  Evolutionary Biology
  Biochemistry
  Animal Physiology
  Russian Library of Science
  
• 出版者：MAIK Nauka/Interperiodica distributed exclusively by Springer Science+Business Media LLC.
• ISSN：1608-3202
• 卷排序：52

文摘

Development of mycoses and progress of humoral and cellular immune responses were compared in larvae of the Colorado potato beetle Leptinotarsa decemlineata infected with entomopathogenic fungi Metarhizium robertsii, M. brunneum and M. pemphigi. The larvae were found to be highly susceptible to the strains of M. robertsii and M. brunneum but weakly responsive to M. pemphigi. The extent of susceptibility to the pathogens was not related to the stimulating effect of epicuticular extracts on fungal growth. Metarhizium pemphigi, which is non-specific to the Colorado potato beetle, did not cause any significant changes in the immune response and did not colonize the hemocoel. When infected with M. robertsii and M. brunneum, the larvae exhibited an increase in hemocyte count during the early stage of mycosis (day 2) followed by a drastic decrease on day 3. The immunocompetent cells, plasmatocytes and granulocytes, exhibited the greatest decrease. Elevated phenoloxidase activity was recorded in the hemolymph and cuticle on days 2 and 3 post-infection. These changes in the immune responses correlated with strain-specific virulence. Thus, the immune response in Colorado potato beetle larvae is an important factor, which determines differences in the development of mycoses caused by different Metarhizium species.Key wordsinsect immunitymycosescuticlephenoloxidasehemocytesMetarhiziumColorado potato beetle