Identification of enzyme inhibitors and antimicrobial activities from Capsicum annuum L. protein extracts against Colletotrichum scovillei

Diseases caused by phytopathogenic microorganisms are difficult to control and can affect plants at different stages of their development. Several resistance genes and antimicrobial peptides (AMPs) have been identified and related to the resistance process of Capsicum. In recent years, studies have shown that peppers, especially the accession UENF1381, present resistance against phytopathogenic microorganisms. This work aimed identify and characterize AMPs of the leaf and root from Capsicum annuum L. UENF1381 and to analyze the inhibitory activity of the AMPs on different enzyme families and valuated the inhibitory activity on Colletotrichum scovillei. Initially, self-fertilized pepper seeds were cultured for 45 days in glass flasks containing ½-MS medium. Then, leaves were inoculated with inoculum of Xanthomonas euvesicatoria (108 CFU mL−1) or water (control). Leaf and root samples were collected at 12, 24 and 48 h after inoculation to extraction. The activity of extracts on different enzyme families was analyzed by incubating the enzymes (trypsin, α-amylase and β-1,3-glucanase) with 30 μg mL−1 of the obtained extracts. The effect of extracts on fungi was also tested. It was identified that protein of leaf and root extracts from C. annuum L. UENF1381 presented a majority of bands with a low molecular mass (6–14 kDa). We observed that all leaf and root extracts significantly inhibited trypsin and α-amylase activity and able to significantly inhibit C. scovillei growth. With this work we hope to contribute to the use of peptides as potential molecules in microbial control and in the development of new Capsicum cultivars resistant to microorganisms.