Special Issue "Biotic and Abiotic Stress Responses in Crop Plants"

A special issue of Agronomy (ISSN 2073-4395). This special issue belongs to the section "Crop Breeding and Genetics".

Deadline for manuscript submissions: closed (1 August 2018).

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A printed edition of this Special Issue is available here.

Special Issue Editors

Prof. Dr. Thomas Dresselhaus
Website
Guest Editor
Cell Biology and Plant Biochemistry, Regensburg Center for Biochemistry, University of Regensburg, 93053 Regensburg, Germany
Interests: flowering time; germline development and function; fertilization mechanisms; haploidy induction; speciation mechanisms; early seed development; heat and infection stress during reproduction; gene regulation; CRPs; signaling mechanisms; RNPs; cell polarity
Prof. Dr. Ralph Hückelhoven
Website
Guest Editor
Phytopathology, TUM School of Life Sciences Weihenstephan, Technical University of Munich, Germany
Interests: plant–microbe interactions; pattern-triggered immunity; disease susceptibility; cellular defense responses; powdery mildew; Fusarium spp.; Pseudomonas spp.; ROP GTPases; receptor-like kinases; programmed cell death; signal transduction; cytoskeleton

Special Issue Information

Dear Colleagues,

While the demands for crop products continues to increase strongly, agricultural productivity is threatened by various stress factors, often associated with global warming. To sustain and improve yield, it is necessary to understand how plants respond to various stresses, and to use the generated knowledge in modern breeding programs. Most knowledge regarding the molecular mechanisms associated with stress responses has been obtained from investigations using the model plant Arabidopsis thaliana. Stress hormones, such as abscisic acid, jasmonic acid, and salicylic acid, have been shown to play key roles in defense responses against abiotic and biotic stresses. More recently, evidence that growth-regulating plant hormones are also involved in stress responses has been accumulating. Epigenetic regulation at the DNA and histone level, and gene regulation by small non-coding RNAs also appear to be important. Many approaches have used mutant screens, as well as next generation sequencing approaches, to identify key players and mechanisms of plant responses to the environment. However, it is often unclear to which extent the elucidated mechanisms also operate in crops.

This Special Issue, therefore, seeks contributions reporting how crop plant species respond to various abiotic stresses, such as drought, heat, cold, flooding, and salinity, as well as biotic stimuli during microbial infections. It welcomes reviews, perspectives, and original articles, and its focus is on our molecular understanding of biotic and abiotic stress responses in crops, highlighting, among other aspects, the role of stress hormones, signaling mechanisms, and changes in gene expression patterns and their regulation. Approaches and ideas to achieve stress tolerance and to maintain yield stability of agricultural crops during stress periods are of specific interest. These include perspectives on how knowledge from model plants can be utilized to facilitate crop-plant breeding and biotechnology.

Prof. Dr. Thomas Dresselhaus
Prof. Dr. Ralph Hückelhoven
Guest Editors

Manuscript Submission Information

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Keywords

  • Agricultural crops
  • Heat and drought stress
  • Cold stress
  • Salinity and flooding
  • Plant immunity
  • Disease susceptibility and resistance
  • Stress hormones
  • Gene regulation
  • Signaling mechanisms
  • Stress tolerance breeding
  • Resistance breeding
  • Biotechnology

Published Papers (15 papers)

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Editorial

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Open AccessEditor’s ChoiceEditorial
Biotic and Abiotic Stress Responses in Crop Plants
Agronomy 2018, 8(11), 267; https://doi.org/10.3390/agronomy8110267 - 19 Nov 2018
Cited by 14
Abstract
Agricultural productivity depends on increasingly extreme weather phenomena, and the use of germplasm that has to be continuously improved by plant breeders to become tolerant to various biotic and abiotic stresses. Molecular plant biologists try to understand the mechanisms associated with stress responses [...] Read more.
Agricultural productivity depends on increasingly extreme weather phenomena, and the use of germplasm that has to be continuously improved by plant breeders to become tolerant to various biotic and abiotic stresses. Molecular plant biologists try to understand the mechanisms associated with stress responses and provide knowledge that could be used in breeding programs. To provide a partial overview about our current understanding about molecular and physiological stress responses, and how this knowledge can be used in agriculture, we have edited a special issue on “Biotic and Abiotic Stress Responses in Crop Plants”. Contributions are from different fields including heat stress responses, stress responses during drought and salinity, as well as during flooding, and resistance and susceptibility to pathogenetic stresses and about the role of plant functional metabolites in biotic stress responses. Future research demand in particular areas of crop stress physiology is discussed, as well as the importance of translational research and investigations directly in elite crop plants and in the genetic resources available for breeding. Full article

Research

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Open AccessArticle
Arabidopsis thaliana Immunity-Related Compounds Modulate Disease Susceptibility in Barley
Agronomy 2018, 8(8), 142; https://doi.org/10.3390/agronomy8080142 - 07 Aug 2018
Cited by 6
Abstract
Plants are exposed to numerous pathogens and fend off many of these with different phytohormone signalling pathways. Much is known about defence signalling in the dicotyledonous model plant Arabidopsisthaliana, but it is unclear to which extent knowledge from model systems can [...] Read more.
Plants are exposed to numerous pathogens and fend off many of these with different phytohormone signalling pathways. Much is known about defence signalling in the dicotyledonous model plant Arabidopsisthaliana, but it is unclear to which extent knowledge from model systems can be transferred to monocotyledonous plants, including cereal crops. Here, we investigated the defence-inducing potential of Arabidopsis resistance-inducing compounds in the cereal crop barley. Salicylic acid (SA), folic acid (Fol), and azelaic acid (AzA), each inducing defence against (hemi-)biotrophic pathogens in Arabidopsis, were applied to barley leaves and the treated and systemic leaves were subsequently inoculated with Xanthomonastranslucens pv. cerealis (Xtc), Blumeria graminis f. sp. hordei (powdery mildew, Bgh), or Pyrenophora teres. Fol and SA reduced Bgh propagation locally and/or systemically, whereas Fol enhanced Xtc growth in barley. AzA reduced Bgh propagation systemically and enhanced Xtc growth locally. Neither SA, Fol, nor AzA influenced lesion sizes caused by the necrotrophic fungus P. teres, suggesting that the tested compounds exclusively affected growth of (hemi-)biotrophic pathogens in barley. In addition to SA, Fol and AzA might thus act as resistance-inducing compounds in barley against Bgh, although adverse effects on the growth of pathogenic bacteria, such as Xtc, are possible. Full article
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Open AccessArticle
Halotolerant Bacterial Diversity Associated with Suaeda fruticosa (L.) Forssk. Improved Growth of Maize under Salinity Stress
Agronomy 2018, 8(8), 131; https://doi.org/10.3390/agronomy8080131 - 28 Jul 2018
Cited by 7
Abstract
Halotolerant bacterial strains associated with the rhizosphere and phytoplane of Suaeda fruticosa (L.) Forssk. growing in saline habitats were isolated to mitigate the salinity stress of Zea mays L. 16S rRNA gene sequencing confirmed the presence of strains that belong to Gracilibacillus, Staphylococcus, [...] Read more.
Halotolerant bacterial strains associated with the rhizosphere and phytoplane of Suaeda fruticosa (L.) Forssk. growing in saline habitats were isolated to mitigate the salinity stress of Zea mays L. 16S rRNA gene sequencing confirmed the presence of strains that belong to Gracilibacillus, Staphylococcus, Virgibacillus, Salinicoccus, Bacillus, Zhihengliuella, Brevibacterium, Oceanobacillus, Exiguobacterium, Pseudomonas, Arthrobacter, and Halomonas genera. Strains were screened for auxin production, 1-aminocyclopropane-1-carboxylate (ACC)-deaminase, and biofilm formation. Bacterial auxin production ranged from 14 to 215 µg mL−1. Moreover, several bacterial isolates were also recorded as positive for ACC-deaminase activity, phosphate solubilization, and biofilm formation. In pot trials, bacterial strains significantly mitigated the salinity stress of Z. mays seedlings. For instance, at 200 and 400 mM NaCl, a significant increase of shoot and root length (up to onefold) was recorded for Staphylococcus jettensis F-11. At 200 mM, Zhihengliuella flava F-9 (45%) and Bacillus megaterium F-58 (42%) exhibited significant improvements for fresh weight. For dry weight, S. jettensis F-11 and S. arlettae F-71 recorded up to a threefold increase at 200 mM over the respective control. The results of this study suggest that natural plant settings of saline habitats are a good source for the isolation of beneficial salt-tolerant bacteria to grow crops under saline conditions. Full article
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Open AccessFeature PaperArticle
Compared to Australian Cultivars, European Summer Wheat (Triticum aestivum) Overreacts When Moderate Heat Stress Is Applied at the Pollen Development Stage
Agronomy 2018, 8(7), 99; https://doi.org/10.3390/agronomy8070099 - 26 Jun 2018
Cited by 6
Abstract
Heat stress frequently imposes a strong negative impact on vegetative and reproductive development of plants leading to severe yield losses. Wheat, a major temperate crop, is more prone to suffer from increased temperatures than most other major crops. With heat waves becoming more [...] Read more.
Heat stress frequently imposes a strong negative impact on vegetative and reproductive development of plants leading to severe yield losses. Wheat, a major temperate crop, is more prone to suffer from increased temperatures than most other major crops. With heat waves becoming more intense and frequent, as a consequence of global warming, a decrease in wheat yield is highly expected. Here, we examined the impact of a short-term (48 h) heat stress on wheat imposed during reproduction at the pollen mitosis stage both, at the physiological and molecular level. We analyzed two sets of summer wheat germplasms from Australia (Kukri, Drysdale, Gladius, and RAC875) and Europe (Epos, Cornetto, Granny, and Chamsin). Heat stress strongly affected gas exchange parameters leading to reduced photosynthetic and transpiration rates in the European cultivars. These effects were less pronounced in Australian cultivars. Pollen viability was also reduced in all European cultivars. At the transcriptional level, the largest group of heat shock factor genes (type A HSFs), which trigger molecular responses as a result of environmental stimuli, showed small variations in gene expression levels in Australian wheat cultivars. In contrast, HSFs in European cultivars, including Epos and Granny, were strongly downregulated and partly even silenced, while the high-yielding variety Chamsin displayed a strong upregulation of type A HSFs. In conclusion, Australian cultivars are well adapted to moderate heat stress compared to European summer wheat. The latter strongly react after heat stress application by downregulating photosynthesis and transpiration rates as well as differentially regulating HSFs gene expression pattern. Full article
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Open AccessArticle
Alleviation of Drought Stress by Nitrogen Application in Brassica campestris ssp. Chinensis L.
Agronomy 2018, 8(5), 66; https://doi.org/10.3390/agronomy8050066 - 04 May 2018
Cited by 9
Abstract
To assess the influence of drought stress on the growth and nitrogen nutrition status of pakchoi (Brassica campestris ssp. Chinensis L.) at different nitrogen (N) levels, the changes in N accumulation and enzyme activities involved in N assimilation were investigated. The drought [...] Read more.
To assess the influence of drought stress on the growth and nitrogen nutrition status of pakchoi (Brassica campestris ssp. Chinensis L.) at different nitrogen (N) levels, the changes in N accumulation and enzyme activities involved in N assimilation were investigated. The drought was induced by adding polyethylene glycol (PEG) under hydroponic culture conditions. Pakchoi seedlings were exposed to a modified nutrient solution with different nitrogen concentration (N1, N2, and N3 represent 2, 9 and 18 mM NaNO3, respectively) and osmotic potential (W1, W2 and W3 represent 0, 60 and 120 g·L−1 PEG 6000) in a full factorial, replicated randomized block design. A short time (seven days) of drought stress caused a significant decline in plant water content, transpiration rate, shoot biomass and shoot nitrogen concentration. Increasing N availability considerably alleviate drought stress by increasing the content of total free amino acids in the roots, promoting the acceleration of root biomass accumulation, and improving the activities of nitrate reductase (NR; EC 1.7.1.1) and glutamine synthetase (GS; EC 6.3.1.2) which would reduce moisture limitations. The results suggested that pakchoi supplied with relative higher N had better growth performance under drought stress. Full article
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Open AccessArticle
Performance and Stability of Commercial Wheat Cultivars under Terminal Heat Stress
Agronomy 2018, 8(4), 37; https://doi.org/10.3390/agronomy8040037 - 29 Mar 2018
Cited by 7
Abstract
Egypt, the fifteenth most populated country and the largest wheat importer worldwide, is vulnerable to global warming. Ten of the commercial and widely grown wheat cultivars were planted in two locations, i.e., Elbostan and Elkhazan for three successive seasons 2014/2015, 2015/2016, and 2016/2017 [...] Read more.
Egypt, the fifteenth most populated country and the largest wheat importer worldwide, is vulnerable to global warming. Ten of the commercial and widely grown wheat cultivars were planted in two locations, i.e., Elbostan and Elkhazan for three successive seasons 2014/2015, 2015/2016, and 2016/2017 under two sowing dates (recommended and late). Elbostan and Elkhazan are the two locations used in this study because they represent newly reclaimed sandy soil and the Nile delta soil (clay), respectively. A split-plot, with main plots arranged as a randomized complete block design and three replicates, was used. The overall objective of this study was to identify the ideal cultivar for recommended conditions and heat stressed conditions. The results revealed that heat stress had a significant adverse impact on all traits while it raised the prevalence and severity of leaf and stem rust which contributed to overall yield losses of about 40%. Stability measurements, the additive main effects and multiplicative interaction model (AMMI) and genotype main effect plus genotype × environment interaction (GGE), were useful to determine the ideal genotypes for recommended and late sowing conditions (heat stressed). However, inconsistency was observed among some of these measurements. Cultivar “Sids12” was stable and outperformed other tested cultivars under combined sowing dates across environments. However, cultivar “Gemmeiza9” was more stable and outperformed other cultivars across environments under the recommended sowing date. Moreover, cultivar “Gemmeiza12” was the ideal cultivar for the late sown condition. Based on our findings, importing and evaluating heat stress tolerant wheat genotypes under late sown conditions or heat stressed conditions in Egypt is required to boost heat stress tolerance in the adapted wheat cultivars. Full article
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Review

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Open AccessReview
A Review of Soil-Improving Cropping Systems for Soil Salinization
Agronomy 2019, 9(6), 295; https://doi.org/10.3390/agronomy9060295 - 06 Jun 2019
Cited by 14
Abstract
A major challenge of the Sustainable Development Goals linked to Agriculture, Food Security, and Nutrition, under the current global crop production paradigm, is that increasing crop yields often have negative environmental impacts. It is therefore urgent to develop and adopt optimal soil-improving cropping [...] Read more.
A major challenge of the Sustainable Development Goals linked to Agriculture, Food Security, and Nutrition, under the current global crop production paradigm, is that increasing crop yields often have negative environmental impacts. It is therefore urgent to develop and adopt optimal soil-improving cropping systems (SICS) that can allow us to decouple these system parameters. Soil salinization is a major environmental hazard that limits agricultural potential and is closely linked to agricultural mismanagement and water resources overexploitation, especially in arid climates. Here we review literature seeking to ameliorate the negative effect of soil salinization on crop productivity and conduct a global meta-analysis of 128 paired soil quality and yield observations from 30 studies. In this regard, we compared the effectivity of different SICS that aim to cope with soil salinization across 11 countries, in order to reveal those that are the most promising. The analysis shows that besides case-specific optimization of irrigation and drainage management, combinations of soil amendments, conditioners, and residue management can contribute to significant reductions of soil salinity while significantly increasing crop yields. These results highlight that conservation agriculture can also achieve the higher yields required for upscaling and sustaining crop production. Full article
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Open AccessReview
Improving Flooding Tolerance of Crop Plants
Agronomy 2018, 8(9), 160; https://doi.org/10.3390/agronomy8090160 - 22 Aug 2018
Cited by 23
Abstract
A major problem of climate change is the increasing duration and frequency of heavy rainfall events. This leads to soil flooding that negatively affects plant growth, eventually leading to death of plants if the flooding persists for several days. Most crop plants are [...] Read more.
A major problem of climate change is the increasing duration and frequency of heavy rainfall events. This leads to soil flooding that negatively affects plant growth, eventually leading to death of plants if the flooding persists for several days. Most crop plants are very sensitive to flooding, and dramatic yield losses occur due to flooding each year. This review summarizes recent progress and approaches to enhance crop resistance to flooding. Most experiments have been done on maize, barley, and soybean. Work on other crops such as wheat and rape has only started. The most promising traits that might enhance crop flooding tolerance are anatomical adaptations such as aerenchyma formation, the formation of a barrier against radial oxygen loss, and the growth of adventitious roots. Metabolic adaptations might be able to improve waterlogging tolerance as well, but more studies are needed in this direction. Reasonable approaches for future studies are quantitative trait locus (QTL) analyses or genome-wide association (GWA) studies in combination with specific tolerance traits that can be easily assessed. The usage of flooding-tolerant relatives or ancestral cultivars of the crop of interest in these experiments might enhance the chances of finding useful tolerance traits to be used in breeding. Full article
Open AccessReview
Plant Protection by Benzoxazinoids—Recent Insights into Biosynthesis and Function
Agronomy 2018, 8(8), 143; https://doi.org/10.3390/agronomy8080143 - 11 Aug 2018
Cited by 13
Abstract
Benzoxazinoids (BXs) are secondary metabolites present in many Poaceae including the major crops maize, wheat, and rye. In contrast to other potentially toxic secondary metabolites, BXs have not been targets of counter selection during breeding and the effect of BXs on insects, microbes, [...] Read more.
Benzoxazinoids (BXs) are secondary metabolites present in many Poaceae including the major crops maize, wheat, and rye. In contrast to other potentially toxic secondary metabolites, BXs have not been targets of counter selection during breeding and the effect of BXs on insects, microbes, and neighbouring plants has been recognised. A broad knowledge about the mode of action and metabolisation in target organisms including herbivorous insects, aphids, and plants has been gathered in the last decades. BX biosynthesis has been elucidated on a molecular level in crop cereals. Recent advances, mainly made by investigations in maize, uncovered a significant diversity in the composition of BXs within one species. The pattern can be specific for single plant lines and dynamic changes triggered by biotic and abiotic stresses were observed. Single BXs might be toxic, repelling, attractive, and even growth-promoting for insects, depending on the particular species. BXs delivered into the soil influence plant and microbial communities. Furthermore, BXs can possibly be used as signalling molecules within the plant. In this review we intend to give an overview of the current data on the biosynthesis, structure, and function of BXs, beyond their characterisation as mere phytotoxins. Full article
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Open AccessReview
Functional Metabolomics—A Useful Tool to Characterize Stress-Induced Metabolome Alterations Opening New Avenues towards Tailoring Food Crop Quality
Agronomy 2018, 8(8), 138; https://doi.org/10.3390/agronomy8080138 - 03 Aug 2018
Cited by 8
Abstract
The breeding of stress-tolerant cultivated plants that would allow for a reduction in harvest losses and undesirable decrease in quality attributes requires a new quality of knowledge on molecular markers associated with relevant agronomic traits, on quantitative metabolic responses of plants to stress [...] Read more.
The breeding of stress-tolerant cultivated plants that would allow for a reduction in harvest losses and undesirable decrease in quality attributes requires a new quality of knowledge on molecular markers associated with relevant agronomic traits, on quantitative metabolic responses of plants to stress challenges, and on the mechanisms controlling the biosynthesis of these molecules. By combining metabolomics with genomics, transcriptomics and proteomics datasets a more comprehensive knowledge of the composition of crop plants used for food or animal feed is possible. In order to optimize crop trait developments, to enhance crop yields and quality, as well as to guarantee nutritional and health factors that provide the possibility to create functional food or feedstuffs, knowledge about the plants’ metabolome is crucial. Next to classical metabolomics studies, this review focuses on several metabolomics-based working techniques, such as sensomics, lipidomics, hormonomics and phytometabolomics, which were used to characterize metabolome alterations during abiotic and biotic stress in order to find resistant food crops with a preferred quality or at least to produce functional food crops. Full article
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Open AccessReview
Unraveling Field Crops Sensitivity to Heat Stress: Mechanisms, Approaches, and Future Prospects
Agronomy 2018, 8(7), 128; https://doi.org/10.3390/agronomy8070128 - 23 Jul 2018
Cited by 12
Abstract
The astonishing increase in temperature presents an alarming threat to crop production worldwide. As evident by huge yield decline in various crops, the escalating drastic impacts of heat stress (HS) are putting global food production as well as nutritional security at high risk. [...] Read more.
The astonishing increase in temperature presents an alarming threat to crop production worldwide. As evident by huge yield decline in various crops, the escalating drastic impacts of heat stress (HS) are putting global food production as well as nutritional security at high risk. HS is a major abiotic stress that influences plant morphology, physiology, reproduction, and productivity worldwide. The physiological and molecular responses to HS are dynamic research areas, and molecular techniques are being adopted for producing heat tolerant crop plants. In this article, we reviewed recent findings, impacts, adoption, and tolerance at the cellular, organellar, and whole plant level and reported several approaches that are used to improve HS tolerance in crop plants. Omics approaches unravel various mechanisms underlying thermotolerance, which is imperative to understand the processes of molecular responses toward HS. Our review about physiological and molecular mechanisms may enlighten ways to develop thermo-tolerant cultivars and to produce crop plants that are agriculturally important in adverse climatic conditions. Full article
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Other

Open AccessOpinion
Generating Plants with Improved Water Use Efficiency
Agronomy 2018, 8(9), 194; https://doi.org/10.3390/agronomy8090194 - 18 Sep 2018
Cited by 11
Abstract
To improve sustainability of agriculture, high yielding crop varieties with improved water use efficiency (WUE) are needed. Despite the feasibility of assessing WUE using different measurement techniques, breeding for WUE and high yield is a major challenge. Factors influencing the trait under field [...] Read more.
To improve sustainability of agriculture, high yielding crop varieties with improved water use efficiency (WUE) are needed. Despite the feasibility of assessing WUE using different measurement techniques, breeding for WUE and high yield is a major challenge. Factors influencing the trait under field conditions are complex, including different scenarios of water availability. Plants with C3 photosynthesis are able to moderately increase WUE by restricting transpiration, resulting in higher intrinsic WUE (iWUE) at the leaf level. However, reduced CO2 uptake negatively influences photosynthesis and possibly growth and yield as well. The negative correlation of growth and WUE could be partly disconnected in model plant species with implications for crops. In this paper, we discuss recent insights obtained for Arabidopsis thaliana (L.) and the potential to translate the findings to C3 and C4 crops. Our data on Zea mays (L.) lines subjected to progressive drought show that there is potential for improvements in WUE of the maize line B73 at the whole plant level (WUEplant). However, changes in iWUE of B73 and Arabidopsis reduced the assimilation rate relatively more in maize. The trade-off observed in the C4 crop possibly limits the effectiveness of approaches aimed at improving iWUE but not necessarily efforts to improve WUEplant. Full article
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Open AccessPerspective
Pattern Recognition Receptors—Versatile Genetic Tools for Engineering Broad-Spectrum Disease Resistance in Crops
Agronomy 2018, 8(8), 134; https://doi.org/10.3390/agronomy8080134 - 01 Aug 2018
Cited by 9
Abstract
Infestations of crop plants with pathogens pose a major threat to global food supply. Exploiting plant defense mechanisms to produce disease-resistant crop varieties is an important strategy to control plant diseases in modern plant breeding and can greatly reduce the application of agrochemicals. [...] Read more.
Infestations of crop plants with pathogens pose a major threat to global food supply. Exploiting plant defense mechanisms to produce disease-resistant crop varieties is an important strategy to control plant diseases in modern plant breeding and can greatly reduce the application of agrochemicals. The discovery of different types of immune receptors and a detailed understanding of their activation and regulation mechanisms in the last decades has paved the way for the deployment of these central plant immune components for genetic plant disease management. This review will focus on a particular class of immune sensors, termed pattern recognition receptors (PRRs), that activate a defense program termed pattern-triggered immunity (PTI) and outline their potential to provide broad-spectrum and potentially durable disease resistance in various crop species—simply by providing plants with enhanced capacities to detect invaders and to rapidly launch their natural defense program. Full article
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Open AccessFeature PaperOpinion
Analysis of Stress Resistance Using Next Generation Techniques
Agronomy 2018, 8(8), 130; https://doi.org/10.3390/agronomy8080130 - 27 Jul 2018
Cited by 4
Abstract
Food security for a growing world population remains one of the most challenging tasks. Rapid climate change accelerates the loss of arable land used for crop production, while it simultaneously imposes increasing biotic and abiotic stresses on crop plants. Analysis and molecular understanding [...] Read more.
Food security for a growing world population remains one of the most challenging tasks. Rapid climate change accelerates the loss of arable land used for crop production, while it simultaneously imposes increasing biotic and abiotic stresses on crop plants. Analysis and molecular understanding of the factors governing stress tolerance is in the focus of scientific and applied research. One plant is often mentioned in the context with stress resistance—Chenopodium quinoa. Through improved breeding strategies and the use of next generation approaches to study and understand quinoa’s salinity tolerance, an important step towards securing food supply is taken. Full article
Open AccessPerspective
Good Riddance? Breaking Disease Susceptibility in the Era of New Breeding Technologies
Agronomy 2018, 8(7), 114; https://doi.org/10.3390/agronomy8070114 - 05 Jul 2018
Cited by 7
Abstract
Despite a high abundance and diversity of natural plant pathogens, plant disease susceptibility is rare. In agriculture however, disease epidemics often occur when virulent pathogens successfully overcome immunity of a single genotype grown in monoculture. Disease epidemics are partially controlled by chemical and [...] Read more.
Despite a high abundance and diversity of natural plant pathogens, plant disease susceptibility is rare. In agriculture however, disease epidemics often occur when virulent pathogens successfully overcome immunity of a single genotype grown in monoculture. Disease epidemics are partially controlled by chemical and genetic plant protection, but pathogen populations show a high potential to adapt to new cultivars or chemical control agents. Therefore, new strategies in breeding and biotechnology are required to obtain durable disease resistance. Generating and exploiting a genetic loss of susceptibility is one of the recent strategies. Better understanding of host susceptibility genes (S) and new breeding technologies now enable the targeted mutation of S genes for genetic plant protection. Here we summarize biological functions of susceptibility factors and both conventional and DNA nuclease-based technologies for the exploitation of S genes. We further discuss the potential trade-offs and whether the genetic loss of susceptibility can provide durable disease resistance. Full article
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