Browsing by Author "Materatski, Patrick"
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- Alternaria alternata an emerging pathogen with great impact on olive grovesPublication . Carvalho, Teresa; Materatski, Patrick; Osa, Nicolás; Patanita, Mariana; Varanda, Carla; Ribeiro, Joana A.; Albuquerque, André; Campos, Maria Doroteia; Félix, M.R.Downy mildew, powdery mildew, grey mould, black rot, and grapevine trunk diseases are among the most important fungal or oomycete diseases affecting grapevine, with a high economic impact in all growing areas. In recent decades, extensive efforts have been made to reduce the use of agrochemicals in viticulture, turning the management of these diseases a major challenge. Given the urgent need to identify and develop new sustainable and effective protection strategies, a better understanding of plant defence mechanisms is essential to develop more tolerant plants and provide valuable insights for disease management. Although recent advances in molecular technologies have allowed the identification of several resistance genes, little is known about the complexity of the molecular mechanisms involved in grapevine-pathogen interactions. This chapter aims to bring together the most up-to-date findings on the regulation of grapevine defence mechanisms against major fungal and oomycete diseases by enumerating promising candidate genes that offer broad possibilities for inducing resistance to specific pathogens. We also focus on the use of functional genomics as a tool to study grapevine immunity to different pathogens, with particular emphasis on new emerging molecular technologies that will undoubtedly contribute to a sustainable plant breeding.
- Biotecnologia vegetal: introdução de um gene de interesse num vetor binário utilizando a tecnologia GatewayPublication . Materatski, Patrick; Varanda, CarlaA Unidade Curricular (UC) de Biotecnologia Vegetal (LBBA1250), é uma UC obrigatória para o 2o ano da Licenciatura em Biologia e Biotecnologia Alimentar. Esta UC compreende, para além das aulas teóricas, uma componente teórico-prática e uma componente de prática-laboratorial, nas quais se pretende que os alunos aprofundem conhecimentos e obtenham competências no método de clonagem, mais especificamente na tecnologia Gateway®, que é um método de clonagem universal baseado nas propriedades de recombinação em local-específico do bacteriófago lambda (Landy, 1989). Esta tecnologia fornece uma forma rápida e altamente eficaz a capacidade de mover sequências de DNA para vários sistemas de vetores para análise funcional de genes e expressão de proteínas (Hartley et al., 2000). Pretende-se ainda que os alunos dominem técnicas de introdução de genes para a expressão de proteínas e silenciamento de genes em plantas indicadoras através de agroinfiltração, tecnologias estas que sustentam os vários domínios da biotecnologia em plantas e seus sistemas e processos. Assim, os protocolos aqui descritos, incluem as principais etapas realizadas num laboratório de biotecnologia vegetal, e uma vez que são transversais em biotecnologia, os estudantes aprendem de forma simples, as principais metodologias usadas rotineiramente num laboratório de biotecnologia vegetal. Este manual descreve os protocolos a realizar nas aulas práticas no ano letivo de 2024/25.
- Biotecnologia vegetal: isolamento e identificação de Colletotrichum spp.Publication . Materatski, Patrick; Varanda, Carla; Varanda, Carla; Materatski, PatrickA Unidade Curricular (UC) de Biotecnologia Vegetal (LBBA1250), é uma UC obrigatória do 2o ano da Licenciatura em Biologia e Biotecnologia Alimentar. Esta UC compreende, para além das aulas teóricas, uma componente teórico-prática e uma componente de prática laboratorial, nas quais se pretende que os estudantes aprofundem conhecimentos e obtenham competências no isolamento e cultura de organismos como bactérias e fungos de plantas de interesse para a região e o país. Pretende-se ainda que os alunos dominem técnicas de extração e identificação molecular que sustentam os vários domínios de aplicação tecnológica das plantas e dos seus sistemas e processos. Assim, os protocolos aqui descritos, incluem várias etapas realizadas num laboratório de biotecnologia vegetal, desde o isolamento de fungos de plantas, à extração e amplificação do DNA e identificação do organismos isolados. Uma vez que os protocolos usados em fungos de plantas são transversais em biotecnologia, os estudantes apreendem de forma simples, as várias das metodologias usadas rotineiramente num laboratório de biotecnologia vegetal. Este manual descreve os protocolos a realizar nas aulas práticas no ano letivo de 2024/25.
- Biotecnologia vegetal: silenciamento de genes em plantaPublication . Materatski, Patrick; Varanda, CarlaA Unidade Curricular (UC) de Biotecnologia Vegetal (LBBA1250), é uma UC obrigatória para o 2o ano da Licenciatura em Biologia e Biotecnologia Alimentar. Esta UC compreende, para além das aulas teóricas, uma componente teórico-prática e uma componente de prática-laboratorial, nas quais se pretende que os alunos aprofundem conhecimentos e obtenham competências no método de silenciamento de genes em planta com recurso a agroinfiltração através de Agrobacterium tumefaciens e que são compatíveis com o vetor binário pK7WG2 (Materatski e Varanda, 2025). Esta metodologia permite a realização de diversos estudos de análise funcional de genes de planta através do silenciamento dos mesmos, bem como a expressão de proteínas específicas. No caso de estudos em virologia, esta tecnologia possibilita também a análise funcional dos genes virais envolvidos na supressão do silenciamento, que é crucial para a correta descrição da biologia das doenças (Varanda, et al., 2018). Estas tecnologias sustentam os vários domínios da biotecnologia em plantas e seus sistemas e processos. Assim, os protocolos aqui descritos, incluem as principais etapas realizadas num laboratório de biotecnologia vegetal, e uma vez que são transversais em biotecnologia, os estudantes aprendem de forma simples, as principais metodologias usadas rotineiramente num laboratório de biotecnologia vegetal. Este manual descreve os protocolos a realizar nas aulas práticas no ano letivo de 2024/25.
- Ciência e tecnologia no diagnóstico de doenças de plantas: avanços para uma agricultura sustentávelPublication . Varanda, Carla; Belbute, Diogo; Magrinho, Beatriz; Materatski, Patrick
- CRISPR/Cas13 system: a technology for the successful control of plant virusesPublication . Ribeiro, Joana A.; Varanda, Carla; Materatski, Patrick; Campos, Maria Doroteia; Albuquerque, André; Patanita, Mariana; Osa, Nicolás; Félix, M.R.Viruses are among the most important causal agents of infectious diseases, having relatively small genomes that comprise RNA or DNA. They have the ability to rapidly replicate and spread throughout a crop, being very difficult to monitor and causing devastating diseases in many agricultural systems. These can lead to significant losses in crop quality and yield, resulting in extreme economic impacts worldwide and threatening the provision of adequate nourishment for a continuous growing population. There are no efficient chemical products that can eliminate an infecting plant virus without perturbing host cells. Therefore, preventive sanitary measures, such as the use of viral resistant or tolerant plants, are usually the only options. Conventionally, these resistant/tolerant plants were generated through a very time- consuming classical breeding process. However, nowadays, molecular plant breeding plays a key role to prevent and control plant viruses. Clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated (Cas) proteins systems allowed the development of a new technology that paves the way towards a new horizon for crop improvement. The first CRISPR/Cas systems studied were very useful for DNA-targeting, however, more recently identified types, such as CRISPR /Cas13, can specifically cleave single- stranded RNA in eukaryotic cells. Therefore, CRISPR/Cas13 is a promising tool for engineering plant immunity against a broad range of RNA viruses, which are the most abundant class of viruses in plants. The present work aims to bring together the most up-to-date information on CRISPR/Cas13 system to control plant viruses, discussing the limitations and future challenges for its application to produce virus resistant plants towards a more sustainable agriculture.
- Current context of Cannabis sativa cultivation and parameters influencing its developmentPublication . Saragoça, Andreia; Silva, Ana; Varanda, Carla; Materatski, Patrick; Ortega, Alfonso; Cordeiro, Ana; Gama, JoséCannabis sativa L. is a versatile plant with significant medicinal, industrial, and recreational applications. Its therapeutic potential is attributed to cannabinoids like THC and CBD, whose production is influenced by environmental factors, such as radiation, temperature, and humidity. Radiation, for instance, is essential for photosynthetic processes, acting as both a primary energy source and a regulator of plant growth and development. This review covers key factors affecting C. sativa cultivation, including photoperiod, light spectrum, cultivation methods, environmental controls, and plant growth regulators. It highlights how these elements influence flowering, biomass, and cannabinoid production across different growing systems, offering insights for optimizing both medicinal and industrial cannabis cultivation. Studies indicate that photoperiod sensitivity varies among cultivars, with some achieving optimal flowering and cannabinoid production under extended light periods rather than the traditional 12/12 h cycle. Light spectrum adjustments, especially red, far-red, and blue wavelengths, significantly impact photosynthesis, plant morphology, and secondary metabolite accumulation. Advances in LED technology allow precise spectral control, enhancing energy efficiency and cannabinoid profiles compared to conventional lighting. The photoperiod plays a vital role in the cultivation of C. sativa spp., directly impacting the plant’s developmental cycle, biomass production, and the concentration of cannabinoids and terpenes. The response to photoperiod varies among different cannabis cultivars, as demonstrated in studies comparing cultivars of diverse genetic origins. On the other hand, indoor or in vitro cultivation may serve as an excellent alternative for plant breeding programs in C. sativa, given the substantial inter-cultivar variability that hinders the fixation of desirable traits.
- Identification of candidate genes involved in olive response to anthracnose for a sustainable disease managementPublication . Inácio, Diogo; Félix, M.R.; Campos, Catarina; Patanita, Mariana; Ribeiro, Joana A.; Varanda, Carla; Materatski, Patrick; Albuquerque, André; Osa, Nicolás; Peixe, A.; Campos, Maria DoroteiaAnthracnose is a disease that affect the olive tree caused by fungi of the genus Colletotrichum. These fungi are responsible to premature fruit drop and a consequent decrease in the oil quality, and also cause defoliation of trees compromising the production of the following years. Currently the best control strategy is based on application of synthetic fungicides, with a regulatory pressure in agriculture worldwide to limit its use. Looking for a sustainable disease management, the present study reports the transcriptional changes of olive genes that encode enzymes directly associated with the maintenance of the balance of oxidative oxygen species (ROS), in response to Colletotrichum sp. infection. The cultivar selected for the studies was ‘Galega vulgar’, known to be extremely susceptible to this disease. Plants used in the experiments were from in vitro culture (to warranty their healthy status), transplanted to pots and maintained under controlled conditions. Leaves of the olive plants were inoculated with a spore suspension of Colletotrichum sp., and leaf samples were collected before fungi inoculation (T0) and at 10 days (T1) and 35 days (T2) after inoculation. Confirmation of the presence of the fungi in inoculated plants was performed following a real-time qPCR approach. The selected target genes for expression analysis were Superoxide dismutase (SOD), Endochitinase_EP3-like (CHI2), Glutathione S-transferase L3-like (TransFL3), Glutathione peroxidase 2 (PEROX2), Glutathione S-transferase THETA 1 (THETA), Glutathione S-transferase DHAR2-like (TransfDHAR), Glutathione peroxidase 5 (PEROX5) and Glutathione peroxidase 8 (PEROX8). Following a qPCR approach, a general up-regulation of the target genes was detected, but only CHI2 revealed a significantly up-regulation (p<0.005) between T0 and T2 in response to Colletotrichum sp. infection, being a promising candidate to be later used in functional analysis. We emphasize the importance of this study for the identification of candidate genes to incorporate new sources of resistance of olive trees to anthracnose with the promotion of the development of sustainable management strategies.
- Insights into grapevine defence response against fungal diseases towards a sustainable plant breedingPublication . Patanita, Mariana; Félix, M.R.; A. Ribeiro, Joana; Varanda, Carla; Albuquerque, André; Materatski, Patrick; Osa, Nicolás; Campos, Maria DoroteiaDowny mildew, powdery mildew, grey mould, black rot, and grapevine trunk diseases are among the most important fungal or oomycete diseases affecting grapevine, with a high economic impact in all growing areas. In recent decades, extensive efforts have been made to reduce the use of agrochemicals in viticulture, turning the management of these diseases a major challenge. Given the urgent need to identify and develop new sustainable and effective protection strategies, a better understanding of plant defence mechanisms is essential to develop more tolerant plants and provide valuable insights for disease management. Although recent advances in molecular technologies have allowed the identification of several resistance genes, little is known about the complexity of the molecular mechanisms involved in grapevine-pathogen interactions. This chapter aims to bring together the most up-to-date findings on the regulation of grapevine defence mechanisms against major fungal and oomycete diseases by enumerating promising candidate genes that offer broad possibilities for inducing resistance to specific pathogens. We also focus on the use of functional genomics as a tool to study grapevine immunity to different pathogens, with particular emphasis on new emerging molecular technologies that will undoubtedly contribute to a sustainable plant breeding.
- Lactic acid bacteria: a sustainable solution against phytopathogenic agentsPublication . Saragoça, A.; Canha, H.; Varanda, Carla; Materatski, Patrick; Cordeiro, A.I.; Gama, J.Biological control agents (BCAs) are beneficial living organisms used in plant protection to control pathogens sustainably. Lactic acid bacteria (LAB) have gained attention in biopesticides due to their safety as recognized by the Food and Drug Administration. These bacteria possess antifungal properties, demonstrating inhibitory effects through nutrient competition or the production of antimicrobial metabolites. Numerous Lactobacillus species have shown the ability to inhibit pathogenic microorganisms, primarily through acid production. The organic acids secreted by LAB reduce the pH of the medium, creating a hostile environment for microorganisms. These organic acids are a primary inhibition mechanism of LAB. This article reviews several studies on LAB as BCAs, focusing on their inhibition modes. Additionally, it discusses the limitations and future challenges of using LAB to control phytopathogens for sustainable agriculture.