Plant Immunity Against Viruses

Plant viruses impose a serious threat on agriculture, which motivates extensive breeding efforts for viral resistant crops and inspires lasting interests on basic research to understand the mechanisms underlying plant immunity against viruses. Viruses are obligate intracellular parasites. Their genomes are usually small and only encode a few products that are essential to hijack host machinery for their nucleotide and protein biosynthesis, and that are necessary to suppress host immunity. Plants evolved multilayers of defense mechanisms to defeat viral infection. In this research topic, we gathered 13 papers covering recent advances in different aspects of plant immunity against viruses, including reviews on RNA silencing and R gene based immunity and their application, translational initiation factor mediated recessive resistance, genome editing based viral immunity, role of chloroplast in plant-virus interaction, and research articles providing new mechanistic insights on plant-virus interactions. We hope that this Research Topic helps readers to have a better understanding of the progresses that have been made recently in plant immunity against viruses. A deeper understanding of plant antiviral immunity will facilitate the development of innovative approaches for crop protections and improvements.

Plant viruses cause many of the most important diseases threatening crops worldwide. Over the last quarter of a century, an increasing number of plant viruses have emerged in various parts of the world, especially in the tropics and subtropics. As is generally observed for plant viruses, most of the emerging viruses are transmitted horizontally by biological vectors, mainly insects. Reverse genetics using infectious clones--available for many plant viruses--has been used for identification of viral determinants involved in virus-host and virus-vector interactions. Although many studies have identified a number of factors involved in disease development and transmission, the precise mechanisms are unknown for most of the virus-plant-vector combinations. In most cases, the diverse outcomes resulting from virus-virus interactions are poorly understood. Although significant advances have been made towards understand the mechanisms involved in plant resistance to viruses, we are far from being able to apply this knowledge to protect cultivated plants from the all viral threats.The aim of this Special Issue was to provide a platform for researchers interested in plant virology to share their recent results. To achieve this, we invited the plant virology community to submit research articles, short communications and reviews related to the various aspects of plant virology: ecology, virus-plant host interactions, virus-vector interactions, virus-virus interactions, and control strategies. This issue contains some of the best current research in plant virology.

An Introduction to Plant Immunity is a comprehensive guide to plant immunology and stress response. The book covers the topic in 21 detailed chapters, starting from an introduction to the subject to the latest knowledge about plant disease resistance. The topics covered in the book include plant pathogens, plant diseases, plant immunity, passive defense mechanisms, acquired resistance, molecular genetics of plant immunology, protein function and genetic engineering. Each chapter provides a reader-friendly introduction along with clear sections detailing each topic. Additionally, detailed references for further reading are also provided. The combination of basic and advanced information on plant immunity make this book an essential textbook for students in botany and plant biology courses. Researchers interested in plant genomics and the effects of environmental and microbial interactions on plants will also benefit from this informative reference.

Molecular Plant Immunity provides an integrated look at both well-established and emerging concepts in plant disease resistance providing the most current information on this important vitally important topic within plant biology. Understanding the molecular basis of the plant immune system has implications on the development of new varieties of sustainable crops, understanding the challenges plant life will face in changing environments, as well as providing a window into immune function that could have translational appeal to human medicine. Molecular Plant Immunity opens with chapters reviewing how the first line of plant immune response is activated followed by chapters looking at the molecular mechanisms that allow fungi, bacteria, and oomycetes to circumvent those defenses. Plant resistance proteins, which provide the second line of plant immune defense, are then covered followed by chapters on the role of hormones in immunity and the mechanisms that modulate specific interaction between plants and viruses. The final chapters look at model plant-pathogen systems to review interaction between plants and fungal, bacterial, and viral pathogens. Written by a leading team of international experts, Molecular Plant Immunity will provide a needed resource to diverse research community investigated plant immunity.

Concern about the environmental consequences of the widespread use of pesticides has increased, and evidence of pesticide-resistant virus vectors have continued to emerge. This volume presents a timely survey of the mechanisms of plant resistance and examines current developments in breeding for resistance, with particular emphasis on advances in genetic engineering which allow for the incorporation of viral genetic material into plants. Discusses the mechanisms of innate resistance in strains of tobacco, tomato, and cowpea; various aspects of induced resistance, including the characterization and roles of the pathogenesis-related proteins; antiviral substances and their comparison with interferon; and cross-protection between plant virus strains. Also presents several papers which evaluate the status of genetic engineering as it relates to breeding resistant plants. Among these are discussions of the potential use of plant viruses as gene vectors, gene coding for viral coat protein, satellite RNA, and antisense RNA, and practical issues such as the durability of resistant crop plants in the field.

The Subject Of Plant Viruses And Virus Diseases Are Receiving Increasing Attention At The Hands Of Research Scholars Such As Chemists, Crystallographers, Entomologists, Geneticists, Serologists, Physicists Etc. They Are Able To Bring Fresh Techniques To The Subject. The Book Is An Attempt To Describe And Correlate The Advances That Have Been Made So Far In The Study Of Plant Viruses, And Virus Diseases. During The Past Few Years, Many New Virus Diseases Have Been Described, Some Of Great Economic Importance And Some With Novel Kinds Of Symptoms; Much Has Been Done On The Factors That Affect Spread; And Insect Vectors Have Been Identified In Species Of Insects Previously Not Incriminated. More Viruses Have Been Purified And Their Chemical Constitution Has Been Further Elucidated, And The Advances In Electron Microscopy Have Provided Much Information On Their Morphology. All These Developments Have Been Incorporated In The Book. The Book Is A Treasure For Agriculture And Horticulture Departments And All Those Interested In These Subjects. Contents Chapter 1: Introduction; Definition Of Subject, Economic Importance, Historical, Views On The Nature Of Viruses, Nomenclature, Chapter 2: External Symptoms Of Infected Plants; Range Of Host Plant Reactions, Type Diseases, Virus Strains, Effects Of Environment On Symptoms, Chapter 3: Internal Symptoms Of Infected Plants; Intracellular Inclusions Formed By Tobacco Mosaic Viruses, Possible Relationship Between Tobacco Mosaic Viruses And The Intracellular Inclusions, Intracellular Inclusions Caused By Viruses Other Than Tobacco Mosaic, Internal Changes Other Than Intracellular Inclusions, Chapter 4: Methods Of Transmission; Grafting And The Use Of Dodder, Inoculation With Plant Extracts, Transmission By Insects, Seed Borne Viruses, Soil Borne Viruses, Chapter 5: The Relations Between Viruses And Their Vectors; Viruses Which Persist In Their Insect Vectors, Latent Period And Virus Multiplication In Vectors, Viruses Whose Vectors Soon Lose Infectivity, Effect Of The Number Of Insects In Transmitting, Chapter 6: Mutation, Interference Between Strains, And Recovery From Disease; Kinds Of Variation, Origin Of Variation, Acquired Immunity, Chapter 7: Serological Reactions Of Plant Viruses; Preparation Of Antisera, Methods Of Testing, The Antigenicity Of Plant Viruses, Neutralisation Of Infectivity, Specificity Of Serological Reactions, Effect Of Particle Shape Of Serological Reactions, Chapter 8: Quantitative Methods Of Assaying For Viruses; The Use Of Local Lesions, Starch Iodine Lesions, The Use Of Preciptin Tests, Chapter 9: The Purification Of Viruses; Treatment Of Plants, Tobacco Mosaic And Other Anisometric Viruses, Tomato Bushy Stunt And Other Crystalline Viruses, High Speed Centrifugation, Activity Of Purifie Preparations, Proteins From Healthy Plants, Chapter 10: Chemical And Physical Properties Of Purified Virus Preparations; Elementary Composition, Isolation And Properties Of Nucleic Acid, The Denatured Protein, Specific Volume And Hydration, Precipitation And Isoelectric Points, Chapter 11: The Crystallinity Of Plant Viruses; Optical Properties Of Crystals, Anistropy Of Flow And The Layering Phenomenon, Crystal And Liquid Crystals, Chapter 12: The Estimation Of Particle Sizes; Filtration, Sedimentation And Diffusion, Microscopy And X-Ray Diffraction, Additional Methods, The Aggregation Of Anisometric Viruses, Chapter 13: Types Of Inactivation; Inhibition Of Infectivity, Inactivation Without Lossof Serological Activity, Inactivation And Denaturation, Chapter 14: Taxonomy Of Viruses; Nomenclature And Classification, The Grouping Of Virus Strains, The Formation Of Larger Groups, Chapter 15: Virus Diseases And Host Plant Physiology; Host Plant Metabolism And Susceptibility, Effects Of Viruses On Host Plant Metabolism, The Movement Of Viruses, Chapter 16: Control Measures Against Virus Diseases; Curative Treatments, General Measures, Insect Borne Viruses, Viruses Transmitted Mechanically, Chapter 17: Speculations On The Origins Of Viruses.

Handbook of Plant Virus Diseases presents basic information about viral-caused and viral-like diseases in many cultivated crops. The editors, internationally known plant pathologists, provide authoritative descriptive symptomatic signatures of virus diseases, to aid in the diagnosis and possible control of viruses. This handbook organizes cultivated plants into groups according to their final destinations and uses after harvest-a useful grouping system that indicates that some diseases, their resultant epidemiology, and control measures are characteristic within different groups.