RESUMEN
Jasmonic acid (JA), a plant endogenously synthesized lipid hormone, plays an important role in response to stress. This manuscript summarized the biosynthesis and metabolism of JA and its related regulatory mechanisms, as well as the signal transduction of JA. The mechanism and regulatory network of JA in plant response to biotic and abiotic stresses were systematically reviewed, with the latest advances highlighted. In addition, this review summarized the signal crosstalk between JA and other hormones in regulating plant resistance to various stresses. Finally, the problems to be solved in the study of plant stress resistance mediated by JA were discussed, and the application of new molecular biological technologies in regulating JA signaling to enhance crop resistance was prospected, with the aim to facilitate future research and application of plant stress resistance.
Asunto(s)
Transducción de Señal , Ciclopentanos , Oxilipinas , Reguladores del Crecimiento de las PlantasRESUMEN
Abstract Utilization of modern breeding techniques for developing high yielding and uniform plant types ultimately narrowing the genetic makeup of most crops. Narrowed genetic makeup of these crops has made them vulnerable towards disease and insect epidemics. For sustainable crop production, genetic variability of these crops must be broadened against various biotic and abiotic stresses. One of the ways to widen genetic configuration of these crops is to identify novel additional sources of durable resistance. In this regard crops wild relatives are providing valuable sources of allelic diversity towards various biotic, abiotic stress tolerance and quality components. For incorporating novel variability from wild relative's wide hybridization technique has become a promising breeding method. For this purpose, wheat-Th. bessarabicum amphiploid, addition and translocation lines have been screened in field and screen house conditions to get novel sources of yellow rust and Karnal bunt resistant. Stripe rust screening under field conditions has revealed addition lines 4JJ and 6JJ as resistant to moderately resistant while addition lines 3JJ, 5JJ, 7JJ and translocation lines Tr-3, Tr-6 as moderately resistant wheat-Thinopyrum-bessarabicum genetic stock. Karnal bunt screening depicted addition lines 5JJ and 4JJ as highly resistant genetic stock. These genetic stocks may be used to introgression novel stripe rust and Karnal bunt resistance from the tertiary gene pool into susceptible wheat backgrounds.
Resumo A utilização de técnicas modernas de melhoramento para o desenvolvimento de tipos de plantas uniformes e de alto rendimento, em última análise, estreitando a composição genética da maioria das culturas. A composição genética restrita dessas plantações tornou-as vulneráveis a doenças e epidemias de insetos. Para uma produção agrícola sustentável, a variabilidade genética dessas culturas deve ser ampliada contra vários estresses bióticos e abióticos. Uma das maneiras de ampliar a configuração genética dessas culturas é identificar novas fontes adicionais de resistência durável. A esse respeito, os parentes selvagens das culturas estão fornecendo fontes valiosas de diversidade alélica para vários componentes de qualidade e tolerância ao estresse abiótico e biótico. Para incorporar a nova variabilidade da ampla técnica de hibridização de parente selvagem tornou-se um método de reprodução promissor. Para esse efeito, trigo-Th. As linhas anfiploides, de adição e translocação de bessarabicum foram selecionadas em condições de campo e de casa de tela para obter novas fontes de ferrugem amarela e resistência ao bunt de Karnal. A triagem de ferrugem em faixas em condições de campo revelou as linhas de adição 4JJ e 6JJ como resistentes a moderadamente resistentes, enquanto as linhas de adição 3JJ, 5JJ, 7JJ e as linhas de translocação Tr-3, Tr-6 como estoque genético de trigo-Thinopyrum bessarabicum moderadamente resistente. A triagem Karnal bunt descreveu as linhas de adição 5JJ e 4JJ como estoque genético altamente resistente. Esses estoques genéticos podem ser usados para introgressão da nova ferrugem e resistência ao bunt de Karnal do pool genético terciário em origens de trigo suscetíveis.
Asunto(s)
Basidiomycota/genética , Triticum/genética , Enfermedades de las Plantas/genética , Cromosomas de las Plantas , Resistencia a la Enfermedad/genética , FitomejoramientoRESUMEN
Utilization of modern breeding techniques for developing high yielding and uniform plant types ultimately narrowing the genetic makeup of most crops. Narrowed genetic makeup of these crops has made them vulnerable towards disease and insect epidemics. For sustainable crop production, genetic variability of these crops must be broadened against various biotic and abiotic stresses. One of the ways to widen genetic configuration of these crops is to identify novel additional sources of durable resistance. In this regard crops wild relatives are providing valuable sources of allelic diversity towards various biotic, abiotic stress tolerance and quality components. For incorporating novel variability from wild relatives wide hybridization technique has become a promising breeding method. For this purpose, wheat-Th. bessarabicum amphiploid, addition and translocation lines have been screened in field and screen house conditions to get novel sources of yellow rust and Karnal bunt resistant. Stripe rust screening under field conditions has revealed addition lines 4JJ and 6JJ as resistant to moderately resistant while addition lines 3JJ, 5JJ, 7JJ and translocation lines Tr-3, Tr-6 as moderately resistant wheat-Thinopyrum-bessarabicum genetic stock. Karnal bunt screening depicted addition lines 5JJ and 4JJ as highly resistant genetic stock. These genetic stocks may be used to introgression novel stripe rust and Karnal bunt resistance from the tertiary gene pool into susceptible wheat backgrounds.
A utilização de técnicas modernas de melhoramento para o desenvolvimento de tipos de plantas uniformes e de alto rendimento, em última análise, estreitando a composição genética da maioria das culturas. A composição genética restrita dessas plantações tornou-as vulneráveis a doenças e epidemias de insetos. Para uma produção agrícola sustentável, a variabilidade genética dessas culturas deve ser ampliada contra vários estresses bióticos e abióticos. Uma das maneiras de ampliar a configuração genética dessas culturas é identificar novas fontes adicionais de resistência durável. A esse respeito, os parentes selvagens das culturas estão fornecendo fontes valiosas de diversidade alélica para vários componentes de qualidade e tolerância ao estresse abiótico e biótico. Para incorporar a nova variabilidade da ampla técnica de hibridização de parente selvagem tornou-se um método de reprodução promissor. Para esse efeito, trigo-Th. As linhas anfiploides, de adição e translocação de bessarabicum foram selecionadas em condições de campo e de casa de tela para obter novas fontes de ferrugem amarela e resistência ao bunt de Karnal. A triagem de ferrugem em faixas em condições de campo revelou as linhas de adição 4JJ e 6JJ como resistentes a moderadamente resistentes, enquanto as linhas de adição 3JJ, 5JJ, 7JJ e as linhas de translocação Tr-3, Tr-6 como estoque genético de trigo-Thinopyrum bessarabicum moderadamente resistente. A triagem Karnal bunt descreveu as linhas de adição 5JJ e 4JJ como estoque genético altamente resistente. Esses estoques genéticos podem ser usados para introgressão da nova ferrugem e resistência ao bunt de Karnal do pool genético terciário em origens de trigo suscetíveis.
Asunto(s)
Control de Plagas/economía , Hongos/genética , Hongos/aislamiento & purificación , Fitomejoramiento/métodos , Triticum/genéticaRESUMEN
Abstract Utilization of modern breeding techniques for developing high yielding and uniform plant types ultimately narrowing the genetic makeup of most crops. Narrowed genetic makeup of these crops has made them vulnerable towards disease and insect epidemics. For sustainable crop production, genetic variability of these crops must be broadened against various biotic and abiotic stresses. One of the ways to widen genetic configuration of these crops is to identify novel additional sources of durable resistance. In this regard crops wild relatives are providing valuable sources of allelic diversity towards various biotic, abiotic stress tolerance and quality components. For incorporating novel variability from wild relatives wide hybridization technique has become a promising breeding method. For this purpose, wheat-Th. bessarabicum amphiploid, addition and translocation lines have been screened in field and screen house conditions to get novel sources of yellow rust and Karnal bunt resistant. Stripe rust screening under field conditions has revealed addition lines 4JJ and 6JJ as resistant to moderately resistant while addition lines 3JJ, 5JJ, 7JJ and translocation lines Tr-3, Tr-6 as moderately resistant wheat-Thinopyrum-bessarabicum genetic stock. Karnal bunt screening depicted addition lines 5JJ and 4JJ as highly resistant genetic stock. These genetic stocks may be used to introgression novel stripe rust and Karnal bunt resistance from the tertiary gene pool into susceptible wheat backgrounds.
Resumo A utilização de técnicas modernas de melhoramento para o desenvolvimento de tipos de plantas uniformes e de alto rendimento, em última análise, estreitando a composição genética da maioria das culturas. A composição genética restrita dessas plantações tornou-as vulneráveis a doenças e epidemias de insetos. Para uma produção agrícola sustentável, a variabilidade genética dessas culturas deve ser ampliada contra vários estresses bióticos e abióticos. Uma das maneiras de ampliar a configuração genética dessas culturas é identificar novas fontes adicionais de resistência durável. A esse respeito, os parentes selvagens das culturas estão fornecendo fontes valiosas de diversidade alélica para vários componentes de qualidade e tolerância ao estresse abiótico e biótico. Para incorporar a nova variabilidade da ampla técnica de hibridização de parente selvagem tornou-se um método de reprodução promissor. Para esse efeito, trigo-Th. As linhas anfiploides, de adição e translocação de bessarabicum foram selecionadas em condições de campo e de casa de tela para obter novas fontes de ferrugem amarela e resistência ao bunt de Karnal. A triagem de ferrugem em faixas em condições de campo revelou as linhas de adição 4JJ e 6JJ como resistentes a moderadamente resistentes, enquanto as linhas de adição 3JJ, 5JJ, 7JJ e as linhas de translocação Tr-3, Tr-6 como estoque genético de trigo-Thinopyrum bessarabicum moderadamente resistente. A triagem Karnal bunt descreveu as linhas de adição 5JJ e 4JJ como estoque genético altamente resistente. Esses estoques genéticos podem ser usados para introgressão da nova ferrugem e resistência ao bunt de Karnal do pool genético terciário em origens de trigo suscetíveis.
RESUMEN
The biotic stress caused by phytopathogens (bacteria, fungus, yeast and insect pests) is a primary factor in yield loss of plants. Biocontrol agents and their active compounds are used to manage such plant pathogens. Here, in our study, we screened four bacterial isolates identified as Bacillus cereus, B. anthracis, B. velezensis and Serratia marcescens after morphological, biochemical and molecular characterization (16s rDNA sequencing) for production of biosurfactant by foam forming activity, oil spreading tests and emulsification activity. Highest foam stability (75 min) and maximum emulsification activity E24% (75%) was observed by B. velezensis strain. Among all the four isolates, Bacillus velezensis strain produced maximum biosurfactant (0.349±0.004 g/50 mL). Biosurfactant of all the four bacterial isolates were checked for fungal inhibiton on PDA plate(s). Bacillus velezensis showed comparatively the highest percent inhibition 58.82, 88.15, 78.45,72.68, 83.96, 75.47, 68.07 and 88.44% against Colletotrichum falcatum, Fusarium oxysporum f sp. ciceri, Helminthosporium maydis, F. oxysporum f. sp. lycopersici, Aspergillus niger, Mucor sp., Helminthosporium oryzae and Rhizoctonia solani, respectively. Bacillus velezensis biosurfactant among all the four bacterial isolates was found to be most effective against the tested phytopathogens
RESUMEN
Yellow mosaic virus (YMV) disease is known to cause severe damage in green gram in terms of yield loss. As the resistance is often governed by recessive genes, introgression of such resistance faces some difficulty. DNA molecular markers are reported to be effective in this process. However, validation of such markers is important. Here, we have made an attempt to validate DNA markers associated with YMV disease resistance gene from a diverse group of 26 green gram genotypes. A total of 19 molecular markers were used to assess the susceptibility or resistance against YMV disease. Results show that among the amplified 31 alleles, 21 were polymorphic, with a mean of 1.1.0 per locus. The polymorphism information content (PIC) values ranged from 0.32 to 0.80. Only five markers exhibited higher PIC value (>6.0) and were revealed to be polymorphic, suggesting its utility in marker assisted selection for breeding YMV resistant genotypes in greengram. Dice dissimilarity coefficient among the genotypes exhibited a range of 0.07 to 1.0 which show a wide genetic variation among the genotypes for YMV tolerance. Neighbor-joining cluster analysis has grouped 26 green gram genotypes into 4 main clusters which revealed the existence of genetic dissimilarities among the genotypes. The genotypes AUGG 6, VBN (Gg) 2 and CO (Gg) 8 carried the positive alleles for YMV disease resistance and the allele for susceptibility were found in the genotypes AUGG 12, AUGG 15, AUGG 17 and AUGG 19. Single marker analysis indicated that there was correlation between the markers and the disease reaction in the field with exceptions. The findings revealed that the SSR markers CEDG180 and YR4 could be used to screen germplasm in order to discriminate the YMV resistant genotypes from the susceptible genotypes in marker assisted selection.
RESUMEN
Xanthomonas axonopodis pv. punicae (Xap) is a bacterial pathogen wreaking havoc in pomegranate cultivation. It causes bacterial blight disease dwindling yield and making fruit unfit for consumption. Physiological and histological investigations during host-pathogen interaction are prerequisite to assess the onset of defense mechanism in plants. Therefore, we tried to compare the pomegranate resistant (IC 318734) and highly susceptible (Ruby) genotypes challenged with Xap. The bacterial suspension containing Xap cells of 0.3 OD600 (~106 to 107CFU mL?1) was used for challenge inoculation. Uniformly grown resistant and highly susceptible plants were selected, the surface of leaves was pricked and spray-inoculated with bacterial suspension using native strain IIHR1 (NCBI Gen Bank ID: KT 222897). Simultaneously, the control plants were also sprayed with only distilled water and observed. A total of three replications with five plants per replication were maintained and evaluated under completely randomized design. Physiological investigations were recorded using Portable photosynthesis system (LCpro+, ADC BioScientific limited, UK) for one cycle of disease progression viz., 0, 1, 5, 10, 15 and 20 days after bacterial spray inoculation (DAI). Significant changes in gas exchange parameters were witnessed on pathogen inoculation. Higher reduction in mean percent change of photosynthetic and transpiration rate, instantaneous water use efficiency, internal CO2 content, stomatal conductance and relative water content were noticed in highly susceptible genotype than resistant one. On contrary, an increased percent mean change of intrinsic water use efficiency, carboxylation capacity and lignin was documented in resistant genotype. Relative injury caused due to bacterial infection was found high in highly susceptible genotype than resistant one. Histological investigations in highly susceptible and resistant genotype were studied on 20th day of Xap inoculation using Scanning Electron Microscopy. Highly susceptible genotype exhibited maximum deformed cells, tissues and other visible abnormalities upon Xap inoculation. Thus, this study forms a basis for effective disease management and breeding programmes in pomegranate.
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Abstract Interactions between plant and pollinators are associated with the origin and maintenance of species diversity, as well as ecosystem functioning. The potential of pollination as an ecosystem service is evidenced by its association with food production. Understanding pollination at the landscape scale is essential for characterizing the pollination service for several crops that depend on pollinators for fruit and seed set that make up the human diet. Our aim was to carry out a literature review of studies and projects funded by BIOTA/FAPESP to illustrate the main research approaches developed in the field of Pollination Biology, especially related to plant-pollinator interactions. Plant-pollinator interactions in the Atlantic forest were leveraged as a result of this long-term research program, during which several papers were published in international journals. Pollination by bees (melittophily) was the most representative pollination system studied. In addition to melittophily, other interactions were studied such as pollination by hawkmoths (sphingophily), by hummingbirds (ornithophily) and by bats (chiropterophily). The specific mutualistic relationships between fig trees and fig wasps were also subject of studies within the Program. At the beginning of the BIOTA/FAPESP Program, there were many gaps in basic information about pollination and breeding systems of Brazilian native plant species. Thus, the Program was fundamental to fuel research on the natural history of plants and pollinators from the Atlantic forest. Overall, the Program funded studies that investigated themes such as functional pollination ecology, pollinator effectiveness, plant population genetics, structure and dynamics of plant-pollinator interaction networks, as well as geographic distribution and macroevolution of pollination systems, as well as genetic and molecular studies of native plant populations focusing on pollen flow and genetic structure of populations. Additionally, studies on pollination in the context of landscape ecology had the aim of assessing the effects of forest fragmentation on the functioning of plant populations and their interactions with pollinators and the relationships between landscape structure and ecological processes, biodiversity, and ecosystem service. Therefore, the Program had a prominent role in producing basic data with great implications for understanding the ecology and promoting the conservation of plant-pollinator interactions.
Resumo A interação planta-polinizador está associada à origem e manutenção da diversidade de espécies de plantas e ao funcionamento dos ecossistemas. O potencial da polinização como serviço ecossistêmico é destacado quando associado à produção de alimentos. Compreender esta interação na escala da paisagem é essencial para caracterizar o serviço de polinização para muitos cultivos que dependem dos polinizadores para a formação de frutos e sementes que integram a dieta humana. O objetivo deste trabalho foi realizar uma revisão bibliográfica de estudos e projetos financiados pelo BIOTA/FAPESP para ilustrar as principais abordagens de pesquisa desenvolvidas no campo da Biologia da Polinização, especialmente relacionadas à interação planta-polinizador. As interações planta-polinizador na Mata Atlântica foram alavancadas como resultado desse programa de pesquisa de longo prazo, durante o qual vários artigos foram publicados em revistas internacionais. A polinização por abelhas (melitofilia) foi o sistema de polinização mais representativo estudado. Além da melitofilia, outras interações foram estudadas, como a polinização por mariposas (esfingofilia), por beija-flores (ornitofilia) e por morcegos (quiropterofilia). As relações mutualísticas específicas entre figueiras e vespas do figo também foram objeto de estudos no âmbito do Programa. No início do Programa BIOTA/FAPESP, havia muitas lacunas sobre informações básicas sobre polinização e sistemas de reprodução de espécies vegetais nativas brasileiras. Assim, o Programa foi fundamental para desenvolver pesquisas sobre a história natural de plantas e polinizadores da Mata Atlântica. No geral, o Programa financiou estudos que investigaram temas como ecologia funcional da polinização, eficácia de polinizadores, genética de populações de plantas, estrutura e dinâmica de redes de interação planta-polinizador, bem como distribuição geográfica e macroevolução dos sistemas de polinização, além de estudos genéticos e moleculares de populações de plantas nativas com foco no fluxo de pólen. Adicionalmente, estudos sobre polinização no contexto da ecologia da paisagem tiveram como objetivo avaliar os efeitos da fragmentação florestal no funcionamento das populações de plantas e suas interações com os polinizadores e as relações entre a estrutura da paisagem e os processos ecológicos, biodiversidade e serviços ecossistêmicos. Portanto, o Programa teve um papel de destaque na produção de dados básicos com grandes implicações para o entendimento da ecologia e promoção da conservação das interações planta-polinizador.
RESUMEN
Plants have a memory function for the environmental stress they have suffered. When they are subjected to repeated environmental stress, they can quickly and better activate the response and adaptation mechanism to environmental stress, thus realizing long-term stable reproduction. However, most of the relevant studies are applied to crops and Arabidopsis thaliana rather than medicinal plants about the improvement of plant growth status and the effect on phytoalexin biosynthesis. In this study, yeast extract(YE) was used as an elicitor to simulate biotic stress, and the changes in biomass and the content of some secondary metabolites were measured by giving repeated stresses to Sorbus aucuparia suspension cell(SASC). The results showed that the accumulation levels of biomass and some secondary metabolites in SASC subjected to repeated stress are significantly increased at some time points compared with single stress. A phenomenon that SASC can memorize biotic stress is confirmed in this study and influences phytoalexin accumulation in SASC. Furthermore, the work laid the groundwork for research into the transgenerational stress memory mechanism of medicinal plant.
Asunto(s)
Células Cultivadas , Metabolismo Secundario , Sorbus , Estrés FisiológicoRESUMEN
In the era of climate change, due to increased incidences of a wide range of various environmental stresses, especially biotic and abiotic stresses around the globe, the performance of plants can be affected by these stresses. After oxygen, silicon (Si) is the second most abundant element in the earth's crust. It is not considered as an important element, but can be thought of as a multi-beneficial quasi-essential element for plants. This review on silicon presents an overview of the versatile role of this element in a variety of plants. Plants absorb silicon through roots from the rhizospheric soil in the form of silicic or monosilicic acid. Silicon plays a key metabolic function in living organisms due to its relative abundance in the atmosphere. Plants with higher content of silicon in shoot or root are very few prone to attack by pests, and exhibit increased stress resistance. However, the more remarkable impact of silicon is the decrease in the number of seed intensities/soil-borne and foliar diseases of major plant varieties that are infected by biotrophic, hemi-biotrophic and necrotrophic pathogens. The amelioration in disease symptoms are due to the effect of silicon on a some factors involved in providing host resistance namely, duration of incubation, size, shape and number of lesions. The formation of a mechanical barrier beneath the cuticle and in the cell walls by the polymerization of silicon was first proposed as to how this element decreases plant disease severity. The current understanding of how this element enhances resistance in plants subjected to biotic stress, the exact functions and mechanisms by which it modulates plant biology by potentiating the host defence mechanism needs to be studied using genomics, metabolomics and proteomics. The role of silicon in helping the plants in adaption to biotic stress has been discussed which will help to plan in a systematic way the development of more sustainable agriculture for food security and safety in the future.
Asunto(s)
Silicio , Estrés Fisiológico , Plantas , Suelo , AgriculturaRESUMEN
ABSTRACT: This study evaluated the essential oils of Melaleuca alternifolia, Casearia sylvestris and Eugenia uniflora as inducers of defense mechanisms in Eucalyptus benthamii seedlings. Four mL of each oil, with a concentration of 0.75% were sprayed in E. benthamii seedlings and two bioassays were performed, in the first, the essential oils were sprayed and after 30 days, sugars, proteins, peroxidases, phenylalanine ammonia (PAL), and phenols were evaluated and; in the second, seven days after the first analysis, the essential oils were again sprayed and after three days, the same variables were evaluated. The essential oils of M. alternifolia, C. sylvestris, and E. uniflora sprayed had no significant effects on E. benthamii seedlings after 30 days in terms of total sugars, proteins, peroxidase, PAL activity, and phenols. However, when M. alternifolia and E. uniflora essential oils were sprayed seven days after the first analysis with evaluation after 3 days, an increase in total sugars was observed. After these days, all essential oils promoted an increase in protein levels. The oils of E. uniflora and C. sylvestris also increased peroxidase levels. The PAL defense enzyme not showed increased when essential oils were used. The essential oils of M. alternifolia and C. sylvestris had potential as inducers of defense mechanisms on E. benthamii seedlings after 3 days of their application, what it demonstrated not be permanent.
RESUMO: Este trabalho teve como objetivo avaliar os óleos essenciais de Melaleuca alternifolia, Casearia sylvestris e Eugenia uniflora como indutores de mecanismos de defesa em mudas de Eucalyptus benthamii. Quatro mL de cada óleo, com concentração de 0,75%, foram pulverizados em mudas de E. benthamii e foram realizados dois bioensaios. No primeiro foram pulverizados os óleos essenciais e após 30 dias, açúcares, proteínas, peroxidases, fenilalanina amônia (PAL) , e fenóis foram avaliados e; na segunda, sete dias após a primeira análise, os óleos essenciais foram novamente pulverizados e após três dias, as mesmas variáveis foram avaliadas. Os óleos essenciais de M. alternifolia, C. sylvestris e E. uniflora pulverizados não tiveram efeito significativo sobre as mudas de E. benthamii após 30 dias em termos de açúcares totais, proteínas, peroxidase, atividade PAL e fenóis. Entretanto, quando os óleos essenciais de M. alternifolia e E. uniflora foram pulverizados sete dias após a primeira análise com avaliação após três dias, foi observado um aumento nos açúcares totais. Depois desses dias, todos os óleos essenciais promoveram aumento nos níveis de proteínas. Os óleos de E. uniflora e C. sylvestris também aumentaram os níveis de peroxidase. A enzima de defesa PAL não se mostrou aumentada quando óleos essenciais foram usados. Os óleos essenciais de M. alternifolia e C. sylvestris apresentaram potencial como indutores de mecanismos de defesa em mudas de E. benthamii após três dias de sua aplicação, o que demonstrou não ser permanente.
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Abstract This work evaluated the effect of seasonality on ant-plant interaction in a Seasonally Dry Tropical Forests, using as an ecological model the species Ipomoea carnea subs. fistulosa (Convolvulaceae). We performed systematic collection of ants, herbivores and leaves in marked plants, evaluated the efficiency of herbivorous capture by ants, and the effects of ant presence over the pollinator behavior and plant fitness in dry and rainy seasons. The presence of ants in the plants reduced the number of herbivores (dry season: F2.27=4.7617, p=0.0166; rainy season: F2.27=5.8655, p=0.0078). However, the capture efficiency was negatively affected by the presence of myrmecophilous larvae, so that the average of ants recruited on termite leaves was 2.06 ants per termite, the average recruitment of ants on larval leaves was 22.4 larva ants. In addition, the presence of ants reduced pollinator visits and promoted fruit reduction during the dry season (ANOVA: F = 3.44; p = 0.0653). In conclusion, the association with ants can result in a balance not always favorable to the host plant, and this result actually depends on abiotic (e.g. precipitation) and biotic factors (e.g. ant species composition and abundance, influence of other trophic levels and identity of associated herbivores).
Resumo Este trabalho avaliou o efeito da sazonalidade sobre a interação planta-formiga em uma Floresta Tropical Sazonal Seca, utilizando como modelo ecológico a espécie Ipomoea carnea subs. fistulosa (Convolvulaceae). Realizamos coleta sistemática de formigas, herbívoros e folhas em plantas marcadas, avaliamos a eficiência de captura de herbívoros pelas formigas, e efeitos da presença de formigas sobre o comportamento dos polinizadores e fitness da planta nas estações seca e chuvosa. A presença de formigas nas plantas reduziu número de herbívoros (estação seca: F2.27 = 4.7617, p = 0.0166; estação chuvosa: F2.27 = 5.8655, p = 0.0078). No entanto, a eficiência de captura foi afetada negativamente pela presença de mirmecófilos larvas, enquanto a média de formigas recrutadas em folhas com cupins foi de 2,06 formigas por cupim, a média de recrutamento de formigas nas folhas com larvas foi de 22,4 formigas de larva. Além disso, a presença de formigas reduziu as visitas aos polinizadores e promoveu a redução de frutos durante a estação seca (F = 3.44, p = 0.0653). Em conclusão, a associação com formigas pode resultar em um balanço nem sempre favorável à planta hospedeira, e este resultado depende de fato de fatores abióticos (e. g. precipitação) e fatores bióticos (e.g. composição e abundância de espécies de formigas, influência de outros níveis tróficos, e identidade dos herbívoros associados).
Asunto(s)
Animales , Hormigas , Plantas , Estaciones del Año , Simbiosis , Bosques , HerbivoriaRESUMEN
Abstract This study aimed to evaluate the effects of florivory and of the patrolling ants associated to EFNs-extrafloral nectaries, on the frequency of floral visitors, using the specie Ipomoea carnea subs. fistulosa (Martius and Choise) in Caatinga area. The floral attributes of the species were characterized. The effect of florivoria on the frequency of visitors and the influence of the presence of ants associated with the NEFs on the pollinator visit rate were evaluated. The rate of natural florivoria was recorded and collected floral visitors and ants over eight months. The damage on floral structure and the presence of ants foraging in the flowers causes a decrease in the number of total visits. The results may be justified by the fact that the floral damage consisted in the loss of important floral attributes. These effects for Ipomoea carnea subs. fistulosa can affect reproductive success, since it is a self-incompatible species and depends on the activity of the pollinators for their fertilization to occur.
Resumo Este trabalho teve por objetivo avaliar o efeito da florivoria e do patrulhamento de formigas nos NEFs - nectários extraflorais sobre a frequência dos visitantes florais, utilizando a espécie Ipomoea carnea subs. fistulosa (Martius e Choise), em uma área de Caatinga. Os atributos florais da espécie foram caracterizados. Foram avaliados o efeito da florivoria sobre a frequência dos visitantes e a influência da presença de formigas associadas aos NEFs sobre a taxa de visita de polinizadores. Ao longo de oito meses foram registrados a taxa de florivoria natural foi registrada e realizada a coleta de visitantes florais e formigas. Os danos na estrutura floral e presença de formigas forrageando nas flores provocam decréscimo no número de visitas totais. Os resultados podem ser justificado pelo fato de que o dano floral consistiu na perda de atributos florais importantes. Estes efeitos para Ipomoea carnea subs. fistulosa podem afetar o sucesso reprodutivo, uma vez que é uma espécie autoincompatível e depende da atividade dos polinizadores para que a sua fecundação ocorra.
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Animales , Hormigas , Convolvulaceae , Ipomoea , Flores , PolinizaciónRESUMEN
Soybean loss due to pests and pathogens is a serious problem worldwide. Soybean producers have few options to manage diseases caused by general pathogens where major genes for full resistance have not been discovered. The innate defense of soybean plants could be enhanced by improving content and composition of lignin by genetic engineering of the phenylpropanoid pathway.We used a novel technique of germ-line genetic transformation of soybean plants via natural pollen tubes as vectors. This technique uses Agrobacterium tumefaciensto mediate transfer of genes of interest to the zygote to introduce the key lignification genes (PtMYB4, PAL5, F5H, CAD1) into soybean genome. We observed 5.6% average transformation efficiency in the first generation of transgenic plants and in the second generation the presence of the transgene constructs was confirmed in more than 50% (for CsVMV/PtMYB4sens, 35SVTM/PAL5, C4H/F5H, CsVMV/CAD1constructs) transgenic soybean lines. We confirmed the expression of the introduced genes at transcriptional level using RT-PCR and Northern blot. Functional analysis using lignin content determination and the activity of PAL5 and CAD1 enzymes demonstrated that the transgenes perform their function in planta. The proposed technique is effectiveand inexpensive and can be used to create novel stress and disease resistant soybean genotypes.
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Ingeniería Genética , Genoma , Metabolismo , Secuenciación Completa del GenomaRESUMEN
This review work focuses on how the secondary chemistry could help in the survival of plants in high mountain habitats under extreme environmental conditions. The elevated levels of stress in high areas of the tropic and subtropic change dramatically not only by following the annual cycles of winter and summer but they also change in a single day. Some species, however, are able to successfully grow at heights more than 3000 m in the tropical mountains due, in part, to highly specialized physiological processes that affect their physical and chemical responses. In this study, it describes some strategies of how the secondary metabolites could help the plants to stand the high levels of stress in the high mountain ecosystems.
Este trabajo de revisioÌn se centra en coÌmo la quiÌmica secundaria podriÌa ayudar en la supervivencia de plantas en haÌbitats de alta montanÌa en condiciones ambientales extremas. Los altos niveles de estreÌs en las zonas altas del troÌpico y subtroÌpico cambian dramaÌticamente no solo al seguir los ciclos anuales de invierno y verano, sino que tambieÌn cambian en un solo diÌa. Sin embargo, algunas especies pueden crecer con eÌxito a alturas superiores a 3000 m en las montanÌas tropicales debido, en parte, a procesos fisioloÌgicos altamente especializados que afectan sus respuestas fiÌsicas y quiÌmicas. En esta revisioÌn, se describen algunas estrategias de coÌmo los metabolitos secundarios podriÌan ayudan a las plantas a soportar los altos niveles de estreÌs en los ecosistemas de alta montanÌa.
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Plantas/química , Estrés Fisiológico , Aceites Volátiles/química , Altitud , Floroglucinol/análisis , Floroglucinol/química , Terpenos/análisis , Terpenos/química , Flavonoides/análisis , Flavonoides/químicaRESUMEN
RESUMEN Se comparó la calidad ecológica del río Tota durante agosto 2007 y febrero 2008, y el curso alto del río Bogotá entre los meses de octubre 2013 y enero 2014, aplicando los índices BMWP/Col y ABI. Los puntos de muestreo corresponden a la parte alta, media y baja del gradiente longitudinal. En el río Tota se determinaron 27 familias correspondientes a 11 órdenes, donde las más abundantes fueron Baetidae (25,43 %), Leptohyphidae (16,43 %), Naididae (13,76 %), Chironomidae (11,42 %) y Hyalellidae (10,30 %). En el curso alto del río Bogotá se determinaron 32 familias correspondientes a 13 órdenes, y las más abundantes fueron Chironomidae (28,94 %), Leptoceridae (25,20 %), Naididae (18,34 %) y Simuliidae (8,63 %). En el río Tota, El BMWP/Col. presentó una calidad de agua buena, mientras que el ABI presentó una calidad aceptable. Por otra parte, en la parte alta del Río Bogotá, tanto el BMWP/ Col. como el ABI presentaron variaciones en la calidad del agua entre aceptable y muy crítica. El ACC para el río Tota mostró correlaciones entre la temperatura y conductividad con las familias Hyalellidae y Leptohyphidae mientras que el caudal se relaciona con Sphaeriidae; mientras que el curso alto del río Bogotá se correlacionó el caudal, la conductividad y la temperatura con la familia Veliidae. A manera de conclusión, los resultados obtenidos denotan que el índice ABI, que es un índice creado para sistemas andinos de montaña, es más sensible a los impactos que el índice BMWP/Col.
ABSTRACT The ecological quality of the Tota River was evaluated during August 2007 and February 2008 and compared to the upper part from Bogotá River between October 2013 and January 2014, by applying the BMWP/Col and ABI indexes. The sampling points corresponding to the high, medium and low part of the longitudinal gradient. In the Tota River, 27 families were determined corresponding to 11 orders, where the most abundant were Baetidae (25.43 %), Leptohyphidae (16.43 %), Naididae (13.76 %), Chironomidae (11.42 %) and Hyalellidae (10.30 %). In the upper course of Bogotá River, 32 families were determined to conform 13 orders, where the most abundant were Chironomidae (28.94 %), Leptoceridae (25.20 %), Naididae (18.34 %) and Simuliidae (8.63 %). In the river Tota, The BMWP/Col. The index showed a good status, while the ABI index exhibited an acceptable quality. On the other hand, in the upper part of the Bogotá River, both the BMWP/Col. and ABI showed variations in quality between acceptable and very critical. The CCA for the Tota River exhibited correlations between temperature and conductivity with the families Hyalellidae and Leptohyphidae while the stream flow was linked with the family Sphaeriidae. On the other hand, in the upper part of Bogotá River the stream flow, conductivity and temperature were correlated with the occurrence of the family Veliidae. Our results showed that the ABI index is more sensitive to impacts that the BMWP/Col index is showing its ability to evaluate the Andean mountain systems.
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Selecting a trait linked to metabolic pathways that enhance resistance and tolerance to biotic and abiotic stresses may be an excellent alternative. A practical approach to increase the productivity of annual crops is to maximize the photosynthetic efficiency in plant breeding. The purpose of this study was to discriminate common bean genotypes during physiological senescence with regard to the stay-green trait and analyze its effects on other traits of agronomic interest. Ten common bean genotypes were analyzed in a randomized complete block design with three replications. The stay-green trait was assessed by visual scores at harvest. The chlorophyll a content, chlorophyll b and green pod color were also evaluated during senescence (75, 80, 85, 90, and 95 days after sowing). Pod maturation of all evaluated genotypes was standard when they reached 95 days after sowing. The stay - green feature was detected only in the genotypes BRS Expedito, FT - Tarumã and BAF071. Genetic variability in the mechanisms related to late senescence is indicated by: i) a high initial chlorophyll a content; and ii) reduced chlorophyll degradation throughout senescence. Plants with stay-green properties were significantly correlated with a lower incidence and severity of plant pathology, greater stem diameter, and higher grain yield.
Selecionar uma característica relacionada às vias metabólicas responsáveis pelo aumento da resistência e/ou tolerância a estresses bióticos e abióticos pode ser uma excelente alternativa no melhoramento de plantas. Uma abordagem prática para aumentar a produtividade das culturas anuais é maximizar a eficiência fotossintética. O objetivo do trabalho foi discriminar genótipos de feijão durante a senescência fisiológica quanto ao caráter stay-green e correlacionar os efeitos sobre outros caracteres de interesse agronômico. Foram avaliados dez genótipos de feijão submetidos ao delineamento de blocos casualizados com três repetições. O caráter stay-green foi mensurado por escores de notas visuais na colheita. Também foram avaliados o teor de clorofila a, teor de clorofila b e coloração verde do legume no decorrer da senescência (75, 80, 85, 90, 95 dias após semeadura). A maturação dos legumes foi padrão para todos osgenótipos avaliados. Os genótipos BRS Expedito, FT - Tarumã e BAF071 apresentaram stay-green, diferentemente dos demais. A variabilidade genética nos mecanismos relacionados a senescência tardia, são detectadas pela: i) elevado teor de clorofila a inicial; e ii) reduzida degradação de clorofila ao longo da senescência. As plantas com stay-green apresentaram correlações significativas com menor incidência e severidade de fitopatologias, maior diâmetro do caule e rendimento de grãos.
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Estrés Fisiológico , Phaseolus , FitomejoramientoRESUMEN
Benthic macroinvertebrates are used as environmental bioindicators in the assessment of water quality in rivers and lakes, due to the sensitivity of some taxa to pollution. The objective of this research was to evaluate the consequences of industrial effluent discharge on the structure of the benthic community present in a river in the subtropical region of Brazil. The organisms were collected at three points of the Coutinho River, in 2013 (September and November) and 2014 (January and March). To characterize the community were calculated density, Shannon diversity index (H ́), Pielou equitability (J), taxa richness, Biotic Indices (Biological Monitoring Working Party - BMWP, Average Score Per Taxon - BMWP-ASPT, Family Biotic Index FBI) and Canonical Correspondence Analysis (CCA) between sampling points and biotic and abiotic variables. Fifteen taxa were identified and among the collected organisms, the family Chironomidae was the most representative, followed by Oligochaeta, Hirudinea, Bivalvia, Gastropoda. According to the results of the biological indices, point 1 indicated moderate pollution and the following points (2 and 3) showed severe pollution. These indices showed poor waters with a high degree of pollution. The results were efficient in detecting the environmental impacts suffered by the river and suggest the necessity of a continuous monitoring of the same.
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Biomarcadores Ambientales/genética , Fauna BénticaRESUMEN
Objective: To explore the functions of pathogenesis related protein 1-like (PR1-like) in suspension cell of Sorbus aucuparia (SaPR1-like) under biotic stress. Method: The full sequence of SaPR1-like gene was cloned and analyzed by multiple bioinformatic tools. The expression of SaPR1-like in the suspension cell of S. aucuparia in response to harpin protein stress was analyzed by real-time fluorescence quantitative polymerase chain reaction (PCR). Result: A SaPR1-like gene was identified and cloned, which contained a complete open reading frame and encoded 161 amino acids. The coding protein was hydrophilic and stable, had transmembrane structure and signal peptide, and belonged to secretory protein. Amino acid sequence alignment data indicated that the C-terminal of SaPR1-like contained a highly conserved domain[cysteine-rich secretory protein, antigen 5, and pathogenesis-related 1 peptides (CAPE)], which could induce defense genes to produce immune responses against biotic stresses. SaPR1-like gene expression was significantly increased after harpin protein induced suspension cell of S. aucuparia for 24 h. Conclusion: A SaPR1-like gene derived from the PR1 family is found to induce significant responses to biotic elicitors in S. aucuparia. This study highlights a role for PR1 in immune signaling and suggests the potential application of PR1 in efforts to defeat biotic stress in plants.
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In the growth condition(s) of plants, numerous secondary metabolites (SMs) are produced by them to serve variety of cellular functions essential for physiological processes, and recent increasing evidences have implicated stress and defense response signaling in their production. The type and concentration(s) of secondary molecule(s) produced by a plant are determined by the species, genotype, physiology, developmental stage and environmental factors during growth. This suggests the physiological adaptive responses employed by various plant taxonomic groups in coping with the stress and defensive stimuli. The past recent decades had witnessed renewed interest to study abiotic factors that influence secondary metabolism during in vitro and in vivo growth of plants. Application of molecular biology tools and techniques are facilitating understanding the signaling processes and pathways involved in the SMs production at subcellular, cellular, organ and whole plant systems during in vivo and in vitro growth, with application in metabolic engineering of biosynthetic pathways intermediates.