Fungal metalloprotease generate whey-derived peptides that may be involved in apoptosis in B16F10 melanoma cells

Abstract Proteases are enzymes that act in the hydrolysis of proteins and have several industrial applications. Moreover, proteases have gained prominence as enzymes for the generation of bioactive peptides from the hydrolysis of different protein sources. Milk is the most studied protein source to obtain peptides due to its nutritional and physiological effects and has been studied as complementary therapeutic approaches for the cancer treatment, interacting specifically with cancer cells, consequently fewer side effects. The ability of Eupenicillium javanicum metalloprotease to generate whey-derived peptides with antioxidant activity has already been demonstrated. For this reason, we thus hypothesized that whey-derived peptides from Eupenicillium javanicum metalloprotease hydrolysis could also have a potential against melanoma cell lines. In this study, B16F10 melanoma cells were treated for 72 h with whey-derived peptides and the effects on cell viability were determined. Moreover, the protein profiles of the treated and nontreated cells were compared in proteomic assay and mass spectrometry analyzes. Whey-derived peptides impaired about 62% cell viability, and proteomic approach associated this behavior to modulate proteins involved in proliferation, energy, apoptosis, metastatic and malignancy rates. This study describes the relevance of microbial enzymes in generation of whey-derived peptides with biological activity against melanoma cells

The Eucalyptus Cuticular Waxes Contribute in Preformed Defense Against Austropuccinia psidii

Austropuccinia psidii, the causal agent of myrtle rust, is a biotrophic pathogen whose growth and development depends on the host tissues. The uredospores of A. psidii infect Eucalyptus by engaging in close contact with the host surface and interacting with the leaf cuticle that provides important chemical and physical signals to trigger the infection process. In this study, the cuticular waxes of Eucalyptus spp. were analyzed to determine their composition or structure and correlation with susceptibility/resistance to A. psidii. Twenty-one Eucalyptus spp. in the field were classified as resistant or susceptible. The resistance/susceptibility level of six Eucalyptus spp. were validated in controlled conditions using qPCR, revealing that the pathogen can germinate on the eucalyptus surface of some species without multiplying in the host. CG-TOF-MS analysis detected 26 compounds in the Eucalyptus spp. cuticle and led to the discovery of the role of hexadecanoic acid in the susceptibility of Eucalyptus grandis and Eucalyptus phaeotricha to A. psidii. We characterized the epicuticular wax morphology of the six previously selected Eucalyptus spp. using scanning electron microscopy and observed different behavior in A. psidii germination during host infection. It was found a correlation of epicuticular morphology on the resistance to A. psidii. However, in this study, we provide the first report of considerable interspecific variation in Eucalyptus spp. on the susceptibility to A. psidii and its correlation with cuticular waxes chemical compounds that seem to play a synergistic role as a preformed defense mechanism

Bacterial community in the rhizosphere and rhizoplane of wild type and transgenic eucalyptus

The rhizosphere is a niche exploited by a wide variety of bacteria. The expression of heterologous genes by plants might become a factor affecting the structure of bacterial communities in the rhizosphere. In a greenhouse experiment, the bacterial community associated to transgenic eucalyptus, carrying the Lhcb1-2 genes from pea (responsible for a higher photosynthetic capacity), was evaluated. The culturable bacterial community associated to transgenic and wild type plants were not different in density, and the Amplified Ribosomal DNA Restriction Analysis (ARDRA) typing of 124 strains revealed dominant ribotypes representing the bacterial orders Burkholderiales, Rhizobiales, and Actinomycetales, the families Xanthomonadaceae, and Bacillaceae, and the genus Mycobacterium. Principal Component Analysis based on the fingerprints obtained by culture-independent Denaturing Gradient Gel Electrophoresis analysis revealed that Alphaproteobacteria, Betaproteobacteria and Actinobacteria communities responded differently to plant genotypes. Similar effects for the cultivation of transgenic eucalyptus to those observed when two genotype-distinct wild type plants are compared.FAPESP (Foundation for Research Assistance, Sao Paulo State, Brazil[02/14143-3]FAPESP (Foundation for Research Assistance, Sao Paulo State, Brazil[03/105274]FAPESP (Foundation for Research Assistance, Sao Paulo State, Brazil[00/14987-1]FAPESP (Foundation for Research Assistance, Sao Paulo State, Brazil[03/01438-8]CNPq (National Council of Research, Brazil