1,721,157 research outputs found
Transgenic approaches for plant disease control:Status and prospects 2021
No full textPlant diseases represent a major constraint on agricultural production. Finding sustainable novel means for their control is an important challenge. The ever-increasing knowledge and understanding of plant-microbe interactions has led to several ingenious transgenic approaches to combat disease. The first transgenic disease-resistant plants expressed single or a few stacked genes encoding antimicrobial proteins. Whereas the first attempts were disappointing in the field, several examples from recent field studies are promising and some of these use ingenious designer approaches. Less progress has been made with antimicrobial metabolites where the challenges lie in obtaining biosynthetic genes and in coordinating their expression. The increased understanding of the processes regulating plant defence (plant immunity) and modes of action of pathogen effector proteins have also led to novel strategies for designing resistant plants. The most promising of these is host-induced gene silencing that targets specific pathogens, either the effectors or, preferably, essential housekeeping genes. With these approaches, and several maverick examples of "genes pulled out of a hat," the technical effort in designing resistant plants is finally paying off. The prospects are good, biologically speaking, but can industry deliver? There is still an issue of public acceptance of genetic engineering of crop plants, especially in Europe; so whilst considerable strategic and practical progress has been made over the last decade, vanishingly few products have been adopted by agriculture. Some of these have been in use for over two decades. As yet, all are against viral diseases and not against diseases caused by microorganisms.</p
Biotechnology for plant disease control.
No full textThis chapter focuses on the development and application of new strategies for combating disease, which are based on the newest knowledge coming from comparative genomics and by molecular genetic manipulation of key components involved in plant defences, pathogenicity and signaling.</p
The status and prospects for biotechnological approaches for attaining sustainable disease resistance
No full textBacterial plant pathogens.
No full textThis chapter provides information on the taxonomy, symptoms, modes of dispersal, infection stages, survival and infection mechanisms and pathogenicity determinants of plant pathogenic bacteria. The lifestyles of some model plant pathogenic bacteria are discussed and some important bacterial diseases of various forest trees, horticultural and field crops are also presented
Biological control of plant diseases.
No full textBiological control can be defined into several categories of which two have special relevance for biological control of plant diseases, i.e. inoculation and conservation biological control. This chapter defines biological control, and provides some tips on how to select a good biological control agent, whose success depends on the target pathogen, the crop, the cropping system, the resident microbiota and the environment. It also describes the mechanisms involved in biological control, such as competition, antibiosis, hyperparasitism (i.e. mycoparasitism, when it relates to fungal-fungal interactions), induced plant disease resistance and microbial plant-growth promotion. The importance of understanding the plant host/disease cycle for optimal biological control is also emphasized
The disease cycle and lifestyles.
No full textAfter the first contact between host and pathogen, a series of specific events follow which leads to the development of a disease and, ultimately, an epidemic. This series of events is called a disease cycle. Often, a disease cycle is essentially the same as the pathogen's life cycle, but the key difference is that a disease cycle primarily describes the disease as it develops as a result of the interaction between the host plant and the pathogen. In the first section of the chapter, a series of terms describing what is essentially a continuum of lifestyles were explained; through commensal via mutualistic and pathogenic to saprophytic. There are two extremes of pathogenic lifestyle-biotrophic and necrotrophic. Pathogens that are purely biotrophic are usually obligate parasites, whereas necrotrophic pathogens can also survive as saprophytes
What is a plant disease?
No full textThis chapter provides an introduction to the various factors, i.e. the host plants, the pathogens (fungi and fungal-like organisms, bacteria, viruses and nematodes) and the environment, and their interactions that may or may not result in a plant disease
Engineering Barriers to Infection by Undermining Pathogen Effector Function or by Gaining Effector Recognition
No full textThis chapter reviews potential disease control strategies by employing the current understanding of Pathogen-Associated Molecular Patterns (PAMPs) and their receptors, as well as effectors and their targets. It discusses how effectoromics, i.e. surveying which, and to what level, effectors are expressed at a pathogen population level, can help to select the most useful and durable R genes. Plant immunity can be boosted by overexpressing a Pattern-Recognition Receptor (PRR) in a closely- or more-distantly related plant to strengthen PAMP-Triggered Immunity (PTI). An interesting aspect of NB-LRR transcript regulation that involves small RNAs is currently emerging and could potentially be explored in the search for more durable and/or broad-spectrum pathogen resistance. The chapter suggests ways that can be used to undermine effector function and be exploited to engineer resistant plants in the future. It further illustrates how a mechanistic understanding of a pathogen's stealth strategies may allow new approaches to engineer resistance.</p
Status of transgenic crops in Argentina
No full textWell‐established regulatory frameworks for the evaluation of genetically modified organism (GMO), together with a long tradition in plant breeding, are some of the reasons for the adoption rate of this technology in Argentina. In October 2015, the first two GMOs developed in Argentina for drought‐tolerant soybean and the Potato virus Y (PVY) resistant potato. All genetically modified crops released in Argentina for commercialization were developed by private companies. Public institutions are working on potatoes, sugar cane, sweet orange, and wheat, among other crops, and several of these have a potential in international markets. Successive field testing of selected lines allowed the identification of two genetically stable PVY‐resistant lines, SY230 and SY233, which were evaluated in field trials at different potato‐producing regions in Argentina. These virus affected plants are now under assessment by Commission on Agricultural Biotechnology (CONABIA) for its commercial release.Fil: Bravo Almonacid, Fernando Felix. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: Segretin, Maria Eugenia. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; Argentin
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