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ABSTRACT. Coffee, an agronomical crop of great economic 2 G.C.V. Bard et al. Genetics and Molecular Research 15 (4): gmr15048859 importance, is also among the most commonly traded commodities in worldwide markets. Antimicrobial peptides, which play a role in plant defense, have been identified and isolated particularly from seeds. We isolated and immunolocalized Cc-LTP2, a new lipid transfer protein (LTP) from Coffea canephora seeds. We report its antimicrobial activity against various phytopathogenic fungi of economic importance, and against the bacterium Xanthomonas euvesicatoria. Peptides from C. canephora seeds were initially extracted using acid buffer and subjected to ion-exchange and reverse-phase chromatographies. A purified peptide of approximately 9 kDa, which we named Cc-LTP2, was then subjected to amino acid sequencing. The analyses showed that it was similar to LTPs isolated from various plants. The tissue and subcellular localization of C. canephora LTPs indicated that they were located in cell walls and intracellular palisade parenchyma, mainly in large vacuoles. The results of immunohistochemistry and histochemistry superposed from C. canephora seed tissues showed that LTPs and lipid bodies are present in organelles, supporting the hypothesis that LTPs from seeds are involved in lipid mobilization during germination. Cc-LTP2 did inhibit the development of the phytopathogenic fungi Colletotrichum lindemuthianum, Colletotrichum gloeosporioides, Fusarium solani, Fusarium lateritium, and Colletotrichum sp, but did inhibit X. euvesicatoria. Cc-LTP2 also increased membrane permeability and induced endogenous production of reactive oxygen species in all the fungi tested.

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Background: A diverse set of antimicrobial molecules have been found mainly in the seeds and fruits of Capsicum annuum UENF1381, accession resistant to different phytopathogenic microorganisms, like bacteria of the genus Xanthomonas and fungi of the genus Colletotrichum. However, there is little information about the defense mechanisms in other plant organs. The work aimed to study the induction of resistance in leaves and roots of C. annuum through the identification and characterization of antimicrobial peptides against Colletotrichum scovillei, one of the main pathogens of the crop.Results: Based on the results of differential protein expression in response to infection, the extracts, LC 48 (Control Leaf mock inoculated 48 h), and RC 48 (Control Root mock inoculated 48 h) were selected. Analysis on the HPLC system resulted in 23 fractions (L1 to L23) obtained from the LC 48 extract and 27 fractions from the RC 48 extract (R1 to R27). Our results show that 10 μg mL À1 of the L1 fraction is able to inhibit 88.4% of fungal growth, causing cell membrane permeabilization, endogenous reactive oxygen species induction and mitochondrial activity reduction. The peptide in the L1 fraction, named CaLPI, showed similarities with different sequences of proteinase inhibitors. Conclusion:The study provides information on the diversity of antimicrobial proteins and peptides present in the leaves and roots of C. annuum UENF1381. With these results, we hope to contribute to the use of peptides as potential molecules in microbial control.