Plants have sophisticated defense systems to fend off insect herbivores. How plants defend against herbivores in dicotyledonous plants, such as Arabidopsis and tobacco, have been relatively well studied, yet little is...Plants have sophisticated defense systems to fend off insect herbivores. How plants defend against herbivores in dicotyledonous plants, such as Arabidopsis and tobacco, have been relatively well studied, yet little is known about the defense responses in monocotyledons. Here, we review the current un- derstanding of rice （Oryza sativa） and maize （Zea rnays） defense against insects. In rice and maize, elicitors derived from insect herbivore oral secretions or oviposition fluids activate phytohormone signaling, and transcriptomic changes mediated mainly by transcription factors lead to accumulation of defense-related secondary metabolites. Direct defenses, such as trypsin protein inhibitors in rice and benzoxazinoids in maize, have anti-digestive or toxic effects on insect herbivores. Herbivory-induced plant volatiles, such as terpenes, are indirect defenses, which attract the natural enemies of herbivores. R gene-mediated defenses against herbivores are also discussed.展开更多
Trichoderma strains are used in agriculture because they provide to the plants the following benefits: i) are rhizosphere competence and establish stable rhizosphere microbial communities; ii) control plant disease ca...Trichoderma strains are used in agriculture because they provide to the plants the following benefits: i) are rhizosphere competence and establish stable rhizosphere microbial communities; ii) control plant disease caused by pathogenic and competitive microflora, by using a variety of mechanisms; iii) improve vegetative growth, root development and yield; iv) make nutrients more available to the plant. In this work we have investigated the ability of T. harzianum T22 and T. atroviride P1 to improve plant growth of locally important horticultural crops: lettuce, tomatoes and peppers and to prevent disease in the greenhouse and field. The effect of the Trichoderma treatment was evaluated by determining the weight of fresh and dry roots and above ground plant biomass, measuring plants height, counting the number of emerged leaves (lettuce, tomatoes and peppers) and quantifying production (tomatoes and peppers). No disease symptoms were found during production, although Fusarium sp. strains pathogenic to tomato were detected in the soil. Compounds containing copper oxychloride are frequently used for fungal disease control in agriculture. In order to investigate the compatibility of T. harzianum T22 and T. atroviride P1 with copper oxychloride applications, the effect on mycelia growth was monitored in both liquid and solid medium. In general, the tests indicated a high level of tolerance of the Trichoderma strains to concentrations of copper oxychloride varying from 0.1 to 5 mmol/L.展开更多
Alternative Low-Input Agriculture Systems （ALIAS） center advocates organic and sustainable food production system through farm/field demonstration and piloting. The center undertakes activities, including research a...Alternative Low-Input Agriculture Systems （ALIAS） center advocates organic and sustainable food production system through farm/field demonstration and piloting. The center undertakes activities, including research and development, extension and training, technology dissemination, linkaging and promotional activities. The study established a campus-based demonstration technology showcasing ALIAS to facilitate easy technology diffusion. The objectives of this research were to promote： （1） bio-fertilizers and plant-based pesticides in managing insect pests and diseases of organic vegetables and fruit crops; （2） lotus-tilapia integration as a new modality of farming system in frequently flooded areas; （3） honeybee as pollinators to enhance productivity of organic vegetable and fruit crops; （4） Adlai as intercrop to organic vegetable and fruit crops in support to rice sufficiency; （5） native chicken-coffee integration. The results show that： （1） microbial inoculants and plant-based pesticides are effective in controlling diseases and insect pest, respectively; （2） lotus integration in tilapia production system have no negative effect on the tilapia yield; （3） honeybees as pollinators enhances fruit setting by 42%-68% in different crops; （4） Adlai is a viable intercrop for organic vegetable and fruit crops; （5） native chicken integration was found to be beneficial in terms of soil fertility, insect pest control, natural weeding practices and cultivation in the coffee plantation.展开更多
The molecular factors involved in the three-way interaction between plant, pathogenic fungi and antagonistic/biocontrol fungi, such as Trichoderma, are still poorly understood, even if they represent a matter of inter...The molecular factors involved in the three-way interaction between plant, pathogenic fungi and antagonistic/biocontrol fungi, such as Trichoderma, are still poorly understood, even if they represent a matter of interest for improving crop management and developing new strategies for plant diseases control. The aim of this work is to investigate the components involved in this interaction and, for this purpose, a proteomic approach was used. 2-D maps of the protein extracts from the single components in various interactions between plants (potato, bean, tobacco or tomato), pathogens (Botrytis cinerea, Rhizoctonia solani or Pythium ultimum) and biocontrol fungi (Trichoderma atroviride strain P1 or Trichoderma harzianum strain T22) were obtained. The proteome of each partner was collected separately and extracted by acetone precipitation in presence of trichloroacetic acid and a reducing agent (DTT). The extracted proteins were separated by isoelectrofocusing (IEF), using IPG (Immobilized pH gradient) strips, followed by SDS-PAGE. In order to improve resolution the separations were performed both on wide than narrow pH range and on different gel lengths. Differential spots were noted in the proteome of the three-way interaction when compared to each single component. These were further characterized by mass spectrometry and in silico analysis with the aim of identifying and cloning the relative genes. During the in vitro interaction of T. harzianum strain T22 with tomato and the culture filtrate or cell walls of pathogens, the spot number was higher than in the presence of pathogen biomass. In terms of Trichoderma differential proteins displayed on 2D gels, the most important changes were obtained in the presence of P. ultimum . During the in vivo interaction with tomato, the antagonist proteome changed much more in presence of soilborne fungi R. solani and P. ultimum than with the foliar fungus B. cinerea, both in terms of total and increased or novel spots. In silico analysis of some of those spots revealed homology with intracellular enzymes (GTPases, hydrolases) and with stress-related proteins (heat shock proteins HSP70, bacteriocin cloacin). Specific proteins in the plant proteome, i.e. pathogenesis-related proteins, have been identified during the in vivo interaction of bean with R. solani and T. atroviride strain P1. This is in agreement with the demonstrated ability of these beneficial fungi to induce plant systemic disease resistance by activating expression of defence-related genes. Proteins extracted from T. atrovride strain P1 which were analysed by mass spectrometry, revealed some interesting homologies with a fungal hydrophobin of Pleurotus ostreatus and an ABC transporter of Ralstonia metallidurans. These could represent molecular factors involved in the antagonistic mechanisms of Trichoderma and play a role in the three-way interaction with the plant and other microbes.展开更多
Antiviral defense is one of the important roles of RNA silencing in plants. Virus-derived small interfering RNAs (vsiRNAs) are found in the infected host cells, indicating that the host RNA silencing machinery can tar...Antiviral defense is one of the important roles of RNA silencing in plants. Virus-derived small interfering RNAs (vsiRNAs) are found in the infected host cells, indicating that the host RNA silencing machinery can target viral RNAs for destruction. With the development of high-throughput sequencing of vsiRNAs, recent genetic studies have shed light on the origin and composition of vsiRNAs and their potential functions in the regulation of gene expression. Here, we briefly describe the origin and biogenesis of vsiRNAs, and review the recent discoveries regarding vsiRNA-mediated RNA silencing of viral genomes and host transcripts. This will better our understanding of virus pathogenicity and RNA silencing-related host-pathogen inter- actions in plants.展开更多
The predatory behavior and functional response of all larval stages and adults of Nephaspis oculatus (Blatchley), a predacious coccinellid, on various egg densities of Bemisia argentifolii Bellows & Perrin...The predatory behavior and functional response of all larval stages and adults of Nephaspis oculatus (Blatchley), a predacious coccinellid, on various egg densities of Bemisia argentifolii Bellows & Perring, and prey preference of adult N. oculatus, were studied in the laboratory. Daily consumption of eggs of B. argentifolii by N. oculatus was evaluated at six different densities to obtain functional response curves for all active stages of the coccinellid. Bemisia argentifolii eggs were offered to N. oculatus on collard leaf disks in Petri dish arenas over a 24\|h period at 26 7 2℃ and a photoperiod of 14∶10 (L∶D) h. Linear relationships were observed between percentage prey consumed and prey density, with r 2 values between 0 82-0 99 for all stages except for the fourth instar that had a smaller r 2 value (0 64). Functional response curves of prey consumption by N. oculatus against density of B. argentifolii eggs fitted the type II model of Holling's disc equation for all larval stages and both the male and female adults. Adult females consumed more prey than adult males. The maximum theoretical number of prey consumed per day increased with larval development. The fourth instar was the most effective larval predator, followed by the third instar, the second instar, and finally, the first instar. Based on the functional response parameters, a maximum of 321, 312, 237, 229, 73, and 34 B. argentifolii eggs could be attacked by an adult female, a fourth instar, an adult male, a third instar, a second instar, and a first instar of N. oculatus, respectively. Nephaspis oculatus adults strongly preferred collard to tomato, soybean, eggplant or sweetpotato for oviposition and foraging. Nephaspis oculatus did not deposit any eggs on soybean and tomato.展开更多
基金supported by the National Natural Science Foundation of China(Nos.31772179,U1502263,31600213,31470369,and 31770301)
文摘Plants have sophisticated defense systems to fend off insect herbivores. How plants defend against herbivores in dicotyledonous plants, such as Arabidopsis and tobacco, have been relatively well studied, yet little is known about the defense responses in monocotyledons. Here, we review the current un- derstanding of rice （Oryza sativa） and maize （Zea rnays） defense against insects. In rice and maize, elicitors derived from insect herbivore oral secretions or oviposition fluids activate phytohormone signaling, and transcriptomic changes mediated mainly by transcription factors lead to accumulation of defense-related secondary metabolites. Direct defenses, such as trypsin protein inhibitors in rice and benzoxazinoids in maize, have anti-digestive or toxic effects on insect herbivores. Herbivory-induced plant volatiles, such as terpenes, are indirect defenses, which attract the natural enemies of herbivores. R gene-mediated defenses against herbivores are also discussed.
文摘Trichoderma strains are used in agriculture because they provide to the plants the following benefits: i) are rhizosphere competence and establish stable rhizosphere microbial communities; ii) control plant disease caused by pathogenic and competitive microflora, by using a variety of mechanisms; iii) improve vegetative growth, root development and yield; iv) make nutrients more available to the plant. In this work we have investigated the ability of T. harzianum T22 and T. atroviride P1 to improve plant growth of locally important horticultural crops: lettuce, tomatoes and peppers and to prevent disease in the greenhouse and field. The effect of the Trichoderma treatment was evaluated by determining the weight of fresh and dry roots and above ground plant biomass, measuring plants height, counting the number of emerged leaves (lettuce, tomatoes and peppers) and quantifying production (tomatoes and peppers). No disease symptoms were found during production, although Fusarium sp. strains pathogenic to tomato were detected in the soil. Compounds containing copper oxychloride are frequently used for fungal disease control in agriculture. In order to investigate the compatibility of T. harzianum T22 and T. atroviride P1 with copper oxychloride applications, the effect on mycelia growth was monitored in both liquid and solid medium. In general, the tests indicated a high level of tolerance of the Trichoderma strains to concentrations of copper oxychloride varying from 0.1 to 5 mmol/L.
文摘Alternative Low-Input Agriculture Systems （ALIAS） center advocates organic and sustainable food production system through farm/field demonstration and piloting. The center undertakes activities, including research and development, extension and training, technology dissemination, linkaging and promotional activities. The study established a campus-based demonstration technology showcasing ALIAS to facilitate easy technology diffusion. The objectives of this research were to promote： （1） bio-fertilizers and plant-based pesticides in managing insect pests and diseases of organic vegetables and fruit crops; （2） lotus-tilapia integration as a new modality of farming system in frequently flooded areas; （3） honeybee as pollinators to enhance productivity of organic vegetable and fruit crops; （4） Adlai as intercrop to organic vegetable and fruit crops in support to rice sufficiency; （5） native chicken-coffee integration. The results show that： （1） microbial inoculants and plant-based pesticides are effective in controlling diseases and insect pest, respectively; （2） lotus integration in tilapia production system have no negative effect on the tilapia yield; （3） honeybees as pollinators enhances fruit setting by 42%-68% in different crops; （4） Adlai is a viable intercrop for organic vegetable and fruit crops; （5） native chicken integration was found to be beneficial in terms of soil fertility, insect pest control, natural weeding practices and cultivation in the coffee plantation.
文摘The molecular factors involved in the three-way interaction between plant, pathogenic fungi and antagonistic/biocontrol fungi, such as Trichoderma, are still poorly understood, even if they represent a matter of interest for improving crop management and developing new strategies for plant diseases control. The aim of this work is to investigate the components involved in this interaction and, for this purpose, a proteomic approach was used. 2-D maps of the protein extracts from the single components in various interactions between plants (potato, bean, tobacco or tomato), pathogens (Botrytis cinerea, Rhizoctonia solani or Pythium ultimum) and biocontrol fungi (Trichoderma atroviride strain P1 or Trichoderma harzianum strain T22) were obtained. The proteome of each partner was collected separately and extracted by acetone precipitation in presence of trichloroacetic acid and a reducing agent (DTT). The extracted proteins were separated by isoelectrofocusing (IEF), using IPG (Immobilized pH gradient) strips, followed by SDS-PAGE. In order to improve resolution the separations were performed both on wide than narrow pH range and on different gel lengths. Differential spots were noted in the proteome of the three-way interaction when compared to each single component. These were further characterized by mass spectrometry and in silico analysis with the aim of identifying and cloning the relative genes. During the in vitro interaction of T. harzianum strain T22 with tomato and the culture filtrate or cell walls of pathogens, the spot number was higher than in the presence of pathogen biomass. In terms of Trichoderma differential proteins displayed on 2D gels, the most important changes were obtained in the presence of P. ultimum . During the in vivo interaction with tomato, the antagonist proteome changed much more in presence of soilborne fungi R. solani and P. ultimum than with the foliar fungus B. cinerea, both in terms of total and increased or novel spots. In silico analysis of some of those spots revealed homology with intracellular enzymes (GTPases, hydrolases) and with stress-related proteins (heat shock proteins HSP70, bacteriocin cloacin). Specific proteins in the plant proteome, i.e. pathogenesis-related proteins, have been identified during the in vivo interaction of bean with R. solani and T. atroviride strain P1. This is in agreement with the demonstrated ability of these beneficial fungi to induce plant systemic disease resistance by activating expression of defence-related genes. Proteins extracted from T. atrovride strain P1 which were analysed by mass spectrometry, revealed some interesting homologies with a fungal hydrophobin of Pleurotus ostreatus and an ABC transporter of Ralstonia metallidurans. These could represent molecular factors involved in the antagonistic mechanisms of Trichoderma and play a role in the three-way interaction with the plant and other microbes.
文摘Antiviral defense is one of the important roles of RNA silencing in plants. Virus-derived small interfering RNAs (vsiRNAs) are found in the infected host cells, indicating that the host RNA silencing machinery can target viral RNAs for destruction. With the development of high-throughput sequencing of vsiRNAs, recent genetic studies have shed light on the origin and composition of vsiRNAs and their potential functions in the regulation of gene expression. Here, we briefly describe the origin and biogenesis of vsiRNAs, and review the recent discoveries regarding vsiRNA-mediated RNA silencing of viral genomes and host transcripts. This will better our understanding of virus pathogenicity and RNA silencing-related host-pathogen inter- actions in plants.
文摘The predatory behavior and functional response of all larval stages and adults of Nephaspis oculatus (Blatchley), a predacious coccinellid, on various egg densities of Bemisia argentifolii Bellows & Perring, and prey preference of adult N. oculatus, were studied in the laboratory. Daily consumption of eggs of B. argentifolii by N. oculatus was evaluated at six different densities to obtain functional response curves for all active stages of the coccinellid. Bemisia argentifolii eggs were offered to N. oculatus on collard leaf disks in Petri dish arenas over a 24\|h period at 26 7 2℃ and a photoperiod of 14∶10 (L∶D) h. Linear relationships were observed between percentage prey consumed and prey density, with r 2 values between 0 82-0 99 for all stages except for the fourth instar that had a smaller r 2 value (0 64). Functional response curves of prey consumption by N. oculatus against density of B. argentifolii eggs fitted the type II model of Holling's disc equation for all larval stages and both the male and female adults. Adult females consumed more prey than adult males. The maximum theoretical number of prey consumed per day increased with larval development. The fourth instar was the most effective larval predator, followed by the third instar, the second instar, and finally, the first instar. Based on the functional response parameters, a maximum of 321, 312, 237, 229, 73, and 34 B. argentifolii eggs could be attacked by an adult female, a fourth instar, an adult male, a third instar, a second instar, and a first instar of N. oculatus, respectively. Nephaspis oculatus adults strongly preferred collard to tomato, soybean, eggplant or sweetpotato for oviposition and foraging. Nephaspis oculatus did not deposit any eggs on soybean and tomato.
