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Previous issue date: 2015-03-18 / The potato is the third most important consumed food in the world. Despite its high productivity, many pest problems cause losses in the quantity and quality of the product. Its high susceptibility to pathogens such as the necrotrophic bacteria Pectobacterium atrosepticum, has led to the indiscriminate use of pesticides, causing damage to the environment and human population. Studies of plant resistance inducers represent an alternative for disease control in some cultures by promoting innate defense system against pathogens. Understanding the changes in plant metabolism related to defense enables the evaluation and development of new strategies and products to disease control. This work aimed was to evaluate some of the mechanisms involved in defense metabolism of Solanum tuberosum in response to the phytobacteria Pectobacterium atrosepticum as well as to the XTH and ASM elicitors.To this end, we analyzed the activities of antioxidant enzymes superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase (APx), enzymes related to defense metabolism, polyphenol oxidase (PPO), peroxidase (POX), phenylalanine ammonia lyase (PAL), and pathogenesis-related proteins, ?-1,3-glucanase and chitinase. It was also determined the synthesis of phenolic compounds and salicylic acid (SA), and the assessment of disease progression caused by the phytobacteria in leaves pretreated with XTH. Our results showed that the elicitor XTH was able to delay the disease progression and symptoms caused by the bacteria P. atrosepticum.The elicitors ASM and XTH promoted the activation of the antioxidant enzymes, as well as the induction of certain enzymes related to defense before and after the bacterial inoculation, differing from the response pattern observed in the leaves treated only with P. atrosepticum. In addition, we observed an increase in free SA levels in leaves treated only with the phytobacteria, differing from the other treatments. In conclusion, the elicitor XTH promotes resistance to the necrotrophic bacteria P. atrospeticum by the defense metabolism activation and modulation of S. tuberosum. / A batata destaca-se como o terceiro alimento mais consumido no mundo. Apesar de sua alta produtividade, in?meros problemas fitossanit?rios v?m causando perdas na quantidade e na qualidade do produto. Sua alta suscetibilidade a pat?genos, como a bact?ria necrotr?fica Pectobacterium atrosepticum, tem levado ao uso indiscriminado de agrot?xicos, causando danos ao meio ambiente e ? popula??o humana. Estudos com indutores de resist?ncia vegetal t?m representado uma alternativa para o controle de doen?as em algumas culturas atrav?s da promo??o do sistema inato de defesa contra pat?genos. Compreender as modifica??es no metabolismo vegetal relacionado ? defesa possibilita a avalia??o e o desenvolvimento de novos recursos e produtos para o manejo fitossanit?rio.Este trabalho teve por objetivo avaliar alguns dos mecanismos envolvidos no metabolismo de defesa de Solanum tuberosum em resposta ? fitopabact?ria Pectobacterium atrosepticum e aos indutores XTH e ASM. Para tal, foram realizadas an?lises de atividade das enzimas antioxidantes super?xido dismutase (SOD), catalase (CAT) e ascorbato peroxidase (APx), das enzimas relacionadas ao metabolismo de defesa, polifenoloxidase (PPO), peroxidase (POX), fenilalanina am?nia liase (PAL), e das prote?nas relacionadas ? pat?genese, ?-1,3-glucanase e quitinase. Foi determinado tamb?m o ac?mulo de compostos fen?licos e de ?cido salic?lico (AS), al?m da avalia??o da manifesta??o da doen?a provocada pela fitobact?ria em folhas pr?-tratadas com XTH. Os resultados demonstraram que o indutor XTH foi capaz de retardar a progress?o e os sintomas da doen?a provocados pela bact?ria P. atrosepticum em folhas de batata.Os indutores XTH e ASM promoveram a ativa??o das enzimas antioxidantes, assim como a indu??o de enzimas relacionadas ? defesa, anteriormente e posteriormente ? inocula??o de P. atrosepticum, diferindo do padr?o de resposta observado nas folhas tratadas apenas com a bact?ria patog?nica. Al?m disso, foi observado um aumento dos n?veis de AS livre nas folhas tratadas apenas com a fitobact?ria, diferindo dos outros tratamentos. A partir destes resultados conclui-se que o indutor XTH promove resist?ncia contra a bact?ria necrotr?fica P. atrospeticum atrav?s da ativa??o e modula??o do metabolismo de defesa em S. tuberosum.
| Identifer | oai:union.ndltd.org:IBICT/oai:tede2.pucrs.br:tede/6268 |
| Date | 18 March 2015 |
| Creators | Faillace, Giulia Ramos |
| Contributors | Astarita, Leandro Vieira |
| Publisher | Pontif?cia Universidade Cat?lica do Rio Grande do Sul, Programa de P?s-Gradua??o em Biologia Celular e Molecular, PUCRS, Brasil, Faculdade de Bioci?ncias |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/masterThesis |
| Format | application/pdf |
| Source | reponame:Biblioteca Digital de Teses e Dissertações da PUC_RS, instname:Pontifícia Universidade Católica do Rio Grande do Sul, instacron:PUC_RS |
| Rights | info:eu-repo/semantics/openAccess |
| Relation | 8198246930096637360, 600, 600, 600, 36528317262667714, -1634559385931244697 |
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