1. A Fructan Exohydrolase from Maize Degrades Both Inulin and Levan and Co-Exists with 1-Kestotriose in Maize.
- Author
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Wu, Silin, Greiner, Steffen, Ma, Chongjian, Zhong, Jiaxin, Huang, Xiaojia, Rausch, Thomas, Zhao, Hongbo, and Voll, Lars Matthias
- Subjects
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INULIN , *CORN , *NICOTIANA benthamiana , *PICHIA pastoris , *ABSCISIC acid , *FRUCTANS , *INVERTASE - Abstract
Enzymes with fructan exohydrolase (FEH) activity are present not only in fructan-synthesizing species but also in non-fructan plants. This has led to speculation about their functions in non-fructan species. Here, a cell wall invertase-related Zm-6&1-FEH2 with no "classical" invertase motif was identified in maize. Following heterologous expression in Pichia pastoris and in Nicotiana benthamiana leaves, the enzyme activity of recombinant Zm-6&1-FEH2 displays substrate specificity with respect to inulin and levan. Subcellular localization showed Zm-6&1-FEH2 exclusively localized in the apoplast, and its expression profile was strongly dependent on plant development and in response to drought and abscisic acid. Furthermore, formation of 1-kestotriose, an oligofructan, was detected in vivo and in vitro and could be hydrolyzed by Zm-6&1-FEH2. In summary, these results support that Zm-6&1-FEH2 enzyme from maize can degrade both inulin-type and levan-type fructans, and the implications of the co-existence of Zm-6&1-FEH2 and 1-kestotriose are discussed. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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