Percorrer por autor "Lima, Marta R. M."
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- Avaliação da susceptibilidade da flora autóctone Portuguesa ao nemátode da madeira do pinheiro (Bursaphelechus xylophilus)Publication . Silva, Marta A. N.; Lima, Marta R. M.; Vasconcelos, Marta W.
- Evaluation of the susceptibility of Portuguese autochthonous flora to the pine wilt nematode (Bursaphelenchus xilophylus)Publication . Silva, Marta A. M.; Lima, Marta R. M.; Vasconcelos, Marta W.
- Evaluation of the susceptibility of portuguese autochthonous flora to the pine wood nematode (bursaphelenchus xylophilus)Publication . Nunes, Marta A.; Lima, Marta R. M.; Vasconcelos, Marta W.
- Evaluation of the susceptibility of Portuguese Autochtonous Flora do the pine wilt nematode (Bursaphelenchus xylophilus)Publication . Silva, Marta A. N.; Lima, Marta R. M.; Vasconcelos, Marta W.
- Intraspecific variation of anatomical and chemical defensive traits in Maritime pine (Pinus pinaster) as factors in susceptibility to the pinewood nematode (Bursaphelenchus xylophilus)Publication . Zas, Rafael; Moreira, Xoaquín; Ramos, Miguel; Lima, Marta R. M.; Silva, Marta Nunes da; Solla, Alejandro; Vasconcelos, Marta; Sampedro, LuisKey message Migration ability of the PWN through wood branch tissues of adult Maritime pine trees significantly differed among Iberian provenances and this variation was related to differences in anatomical and chemical defensive traits. Abstract The pinewood nematode or pine wilt nematode (PWN; Bursaphelenchus xylophilus) is one of the most dangerous threats to European coniferous forests, especially for the susceptible Maritime pine (Pinus pinaster), a valuable forest resource in South Western Europe. The PWN is vectored by beetles of the genus Monochamus (Coleoptera, Cerambycidae) and once inoculated in healthy branches, it quickly migrates downward to the main trunk through the resin canal system. Therefore, the anatomy of the resin canal system may modulate its migration and proliferation rates. Using material from nine Maritime pine Iberian provenances established in a common garden trial, we investigated whether these provenances differed in their (1) resin canal anatomy, (2) concentration of chemical defences (non-volatile resin and total polyphenolics) in stems and (3) ability of the PWN to migrate through the pine woody tissues in ‘in vitro’ bioassays. Whether variation in anatomical and chemical defensive traits relates to differences in PWN migration across populations was also investigated. Significant intraspecific variation in anatomical and chemical defensive traits and in nematode migration rates through pine tissues was observed. Moreover, the variation in nematode migration rate among pine provenances was related to differences in both anatomical and chemical features. Overall, this study highlights the role of plant genetics in the development of defensive traits against this harmful coniferous pest. The observed intraspecific variation should be taken into account when considering breeding as a strategy to provide areas of high risk of PWN with resistant genetic material.
- Nuclear magnetic resonance metabolomics of iron deficiency in soybean leavesPublication . Lima, Marta R. M.; Diaz, Sílvia O.; Lamego, Inês; Grusak, Michael A.; Vasconcelos, Marta; Gil, Ana M.Iron (Fe) deficiency is an important agricultural concern that leads to lower yields and crop quality. A better understanding of the condition at the metabolome level could contribute to the design of strategies to ameliorate Fe-deficiency problems. Fe-sufficient and Fe-deficient soybean leaf extracts and whole leaves were analyzed by liquid 1H nuclear magnetic resonance (NMR) and high-resolution magic-angle spinning NMR spectroscopy, respectively. Overall, 30 compounds were measurable and identifiable (comprising amino and organic acids, fatty acids, carbohydrates, alcohols, polyphenols, and others), along with 22 additional spin systems (still unassigned). Thus, metabolite differences between treatment conditions could be evaluated for different compound families simultaneously. Statistically relevant metabolite changes upon Fe deficiency included higher levels of alanine, asparagine/aspartate, threonine, valine, GABA, acetate, choline, ethanolamine, hypoxanthine, trigonelline, and polyphenols and lower levels of citrate, malate, ethanol, methanol, chlorogenate, and 3-methyl-2-oxovalerate. The data indicate that the main metabolic impacts of Fe deficiency in soybean include enhanced tricarboxylic acid cycle activity, enhanced activation of oxidative stress protection mechanisms and enhanced amino acid accumulation. Metabolites showing accumulation differences in Fe-starved but visually asymptomatic leaves could serve as biomarkers for early detection of Fe-deficiency stress.
- Pestes invasoras: procura de novas soluções para um velho problemaPublication . Lima, Marta R. M.; Santos, Carla; Roriz, Mariana; Nunes, Marta; Vasconcelos, Marta W.
- Potential of chitosan supplementation for remediation of iron deficiency chlorosis in soybean (Glycine max)Publication . Lima, Marta R. M.; Vasconcelos, Marta W.; Grusak, Michael A.
- Produção diferencial de compostos voláteis em caules de pinus pinaster inoculados com o nemátode da madeira do pinheiroPublication . Lima, Marta R. M.; Ferreira, António C. Silva; Vasconcelos, Marta W.O nemátode da madeira do pinheiro (NMP), Bursaphelenchus xylophilus, é o principal agente causal da doença da murchidão do pinheiro. Esta é uma enfermidade grave que afecta florestas de coníferas com uma elevada taxa de mortalidade. Presentemente não são conhecidos meios eficazes de combate à doença da murchidão do pinheiro, apesar da enfermidade ser conhecida e ser alvo de investigação há várias décadas. A complexidade desta doença, na qual vários mecanismos de patogénese parecem agir em simultâneo, contribui em grande parte para a inexistência de um tratamento eficaz, pelo que o aprofundamento do conhecimento da doença é fundamental. Neste trabalho usou-se SPME-GC/MS para estudar a modificação na composição de compostos de natureza volátil em caules de Pinus pinaster após inoculação com NMP. A componente volátil de caules inoculados mostrou ser significativamente diferente de caules controlo. Uma análise estatística multivariada de componentes principais (PCA) demonstrou uma completa separação dos 2 grupos.
- Produção diferencial de compostos voláteis em caules de Pinus pinaster inoculados com o nemátode da madeira do pinheiro (Bursaphelenchus xylophilus)Publication . Lima, Marta R. M.; Ferreira, António C. Silva; Vasconcelos, Marta W.