کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
2840464 1165323 2013 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
A metabolic pathway assembled by enzyme selection may support herbivory of leaf-cutter ants on plant starch
موضوعات مرتبط
علوم زیستی و بیوفناوری علوم کشاورزی و بیولوژیک دانش حشره شناسی
پیش نمایش صفحه اول مقاله
A metabolic pathway assembled by enzyme selection may support herbivory of leaf-cutter ants on plant starch
چکیده انگلیسی

Mutualistic associations shape the evolution in different organism groups. The association between the leaf-cutter ant Atta sexdens and the basidiomycete fungus Leucoagaricus gongylophorus has enabled them to degrade starch from plant material generating glucose, which is a major food source for both mutualists. Starch degradation is promoted by enzymes contained in the fecal fluid that ants deposit on the fungus culture in cut leaves inside the nests. To understand the dynamics of starch degradation in ant nests, we purified and characterized starch degrading enzymes from the ant fecal fluid and from laboratory cultures of L. gongylophorus and found that the ants intestine positively selects fungal α-amylase and a maltase likely produced by the ants, as a negative selection is imposed to fungal maltase and ant α-amylases. Selected enzymes are more resistant to catabolic repression by glucose and proposed to structure a metabolic pathway in which the fungal α-amylase initiates starch catalysis to generate byproducts which are sequentially degraded by the maltase to produce glucose. The pathway is responsible for effective degradation of starch and proposed to represent a major evolutionary innovation enabling efficient starch assimilation from plant material by leaf-cutters.

Figure optionsDownload as PowerPoint slideHighlights
► Leaf-cutter ants live in an obligate mutualism with a basidiomycete fungus.
► Ants and fungus produce their own amylases and maltases.
► Ant gut positively selects fungal amylase and a maltase which may be produced by the ants.
► These enzymes compose a pathway for ant nutrition on plant starch.
► The pathway is an evolutionary innovation supporting leaf-cutter ant herbivory.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Insect Physiology - Volume 59, Issue 5, May 2013, Pages 525–531
نویسندگان
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