Percorrer por autor "Vaz, M."
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- Cloning, characterization and in vitro and in planta expression of a glucanase inhibitor protein (GIP) of Phytophthora cinnamomiPublication . Martins, I.; Martins, F.; Belo, H.; Vaz, M.; Carvalho, M.; Cravador, A.; Choupina, A.Oomycetes from the genus Phytophthora are fungus-like plant pathogens that are devastating for agriculture and natural ecosystems. They are able to secrete a glucanase inhibitor protein (GIP) that inhibits the activity of endoglucanases (EGases) involved in defense responses against infection. One of the most widely distributed and aggressive Phytophthora species, with more than 1,000 host plants is P. cinnamomi. In this work we report the sequencing and characterization of a class of GIPs secreted by Phytophthora cinnamomi. The gip gene from P. cinnamomi has a 937 bp ORF encoding a putative peptide of 312 deduced amino acids. The expression of this gene was studied during growth in different carbon sources (glucose, cellulose and sawdust), by RT-qPCR and its level of expression was evaluated at five time points. The highest expression of gip gene occurred in sawdust at 8 h of induction. In vivo infection of C. sativa revealed an increase in gip expression from 12 to 24 h. At 36 h its expression decreased suggesting that a compensatory mechanism must occur in plant.
- Dietary supplementation with algae-based ingredients modulates antioxidant defenses and immune response in sea urchin Paracentrotus lividus following a Vibrio parahaemolyticus challengePublication . Rodrigues, Ana Filipa; Lourenço, S.; Gomes, Ana Sofia; Vaz, M.; Cardoso, H.; Violante, A. P.; Baptista, T.Functional diets are increasingly recognized as an important strategy to enhance health and production performance in sea urchin aquaculture. This study evaluates the effects of diets containing algae-based ingredients with different carotenoid pigment profiles on the immune and antioxidant systems of the sea urchin Paracentrotus lividus. During a 60-day nutritional trial, sea urchins were fed one of three diets that differed in both ingredient matrix and pigment profile: 1) a base diet formulated without algae and low in carotenoid pigments; 2) a formulated pumpkin/algal diet supplemented with Nannochloropsis sp. and high in β-carotene (nanno diet); and 3) a kelp diet based on Saccorhiza polyschides containing a mixture of carotenoid pigments and representing the natural diet of P. lividus. The effects of diets on oxidative stress response were assessed by quantifying catalase (CAT) and superoxide dismutase (SOD) activities and lipid peroxidation (LPO). The effect of diets on the short-term immune response was assessed using a time-course challenge with Vibrio parahaemolyticus at the end of the feeding trial. Sea urchins fed the kelp diet showed the strongest antioxidant defenses, while sea urchins fed the base diet presented higher LPO. After the pathogen challenge, total coelomocyte density was not significantly affected by diet. However, significant diet-dependent changes were observed in specific coelomocyte populations, including colorless granulocytes, red granulocytes and vibratile cells. Sea urchins fed the kelp diet exhibited a more pronounced immune activation, characterized by higher concentrations of lysozyme. In conclusion, supplementing diets with algae rich in carotenoids and other bioactive compounds may enhance sea urchin immune defenses against pathogens and improve resistance to oxidant stress. These findings support the development of functional diets for sea urchin aquaculture aimed at promoting health and resilience under culture conditions.