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  • Plant defensin M t De f 4 ‐derived antifungal peptide with multiple modes of action and potential as a bio‐inspired fungicide
Title: Plant defensin M t De f 4 ‐derived antifungal peptide with multiple modes of action and potential as a bio‐inspired fungicide
Abstract Chemical fungicides have been instrumental in protecting crops from fungal diseases. However, increasing fungal resistance to many of the single‐site chemical fungicides calls for the development of new antifungal agents with novel modes of action (MoA). The sequence‐divergent cysteine‐rich antifungal defensins with multisite MoA are promising starting templates for design of novel peptide‐based fungicides. Here, we experimentally tested such a set of 17‐amino‐acid peptides containing the γ‐core motif of the antifungal plant defensin MtDef4. These designed peptides exhibited antifungal properties different from those of MtDef4. Focused analysis of a lead peptide, GMA4CG_V6, showed that it was a random coil in solution with little or no secondary structure elements. Additionally, it exhibited potent cation‐tolerant antifungal activity against the plant fungal pathogenBotrytis cinerea, the causal agent of grey mould disease in fruits and vegetables. Its multisite MoA involved localization predominantly to the plasma membrane, permeabilization of the plasma membrane, rapid internalization into the vacuole and cytoplasm, and affinity for the bioactive phosphoinositides phosphatidylinositol 3‐phosphate (PI3P), PI4P, and PI5P. The sequence motif RRRW was identified as a major determinant of the antifungal activity of this peptide. While topical spray application of GMA4CG_V6 onNicotiana benthamianaand tomato plants provided preventive and curative suppression of grey mould disease symptoms, the peptide was not internalized into plant cells. Our findings open the possibility that truncated and modified defensin‐derived peptides containing the γ‐core sequence could serve as promising candidates for further development of bio‐inspired fungicides.  more » « less
Award ID(s):
2018962
PAR ID:
10487459
Author(s) / Creator(s):
; ; ; ; ;
Publisher / Repository:
Wiley
Date Published:
Journal Name:
Molecular Plant Pathology
Volume:
24
Issue:
8
ISSN:
1464-6722
Page Range / eLocation ID:
896 to 913
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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