Resistance Breeding Research Articles

Registration of CDL‐111 and CDL‐167 oat germplasm lines with pyramided adult plant crown rust resistance

AbstractOat (Avena sativa) production worldwide is constrained by crown rust (caused by Puccinia coronata f. sp. avenae), which can cause significant yield losses. The disease is often controlled by spraying fungicides or planting resistant cultivars. Developing host resistance, however, is a challenge due to the high genetic variability of the pathogen. Race‐specific resistance usually succumbs to new races in just a few years. As such, the USDA‐ARS Cereal Disease Laboratory developed mapping populations to identify adult plant resistance (APR) loci from Avena sativa donors. Resistant lines from the mapping populations were selected and crossed with buckthorn (Rhamnus cathartica L.) nursery selection lines BT1020‐1‐1 and BT1021‐1‐1, which possess a different gene for crown rust resistance derived from Avena strigosa. From the crosses, CDL‐111 (Reg. no. GP‐122, PI 702639) and CDL‐167 (Reg. no. GP‐123, PI 702640), both containing three APR quantitative trait loci, were selected as germplasm for resistance breeding. High‐throughput markers for selection were developed and implemented in pyramiding the APR loci.

Biochemical characterization and metabolic reprogramming of amino acids in Soybean roots under drought stress.

Amino acids play important roles in stress resistance, plant growth, development, and quality, with roots serving as the primary organs for drought response. We conducted biochemical and multi-omics analyses to investigate the metabolic processes of root amino acids in drought-resistant (HN44) and drought-sensitive (HN65) soybean (Glycine max) varieties. Our analysis revealed an increase in total amino acid content in both varieties, with phenylalanine, proline, and methionine accumulating in both. Additionally, several amino acids exhibited significant decreases in HN65 but slight increases in HN44. Multi-omics association analysis identified 13 amino acid-related pathways. We thoroughly examined the changes in genes and metabolites involved in various amino acid metabolism/synthesis and determined core genes and metabolites through correlation networks. The phenylalanine, tyrosine, and tryptophan metabolic pathways and proline, glutamic acid and sulfur-containing amino acid pathways were particularly important for drought resistance. Some candidate genes, such as ProDH and P4HA family genes, and metabolites, such as O-acetyl-L-serine, directly affected up- and downstream metabolism to induce drought resistance. This study provided a basis for soybean drought resistance breeding.

Diversification of Toll-like receptor 1 in swamp eel (Monopterus albus)

Toll-like receptor 1 (TLR1) is a pattern recognition receptor that plays critical roles in triggering immune activation via detecting bacterial lipoproteins and lipopeptides. In this study, the genetic characteristic of TLR1 was studied for an important aquaculture fish, swamp eel Monopterus albus. The eel has been seriously threatened by infectious diseases. However, a low level of genetic heterogeneity in the fish that has resulted from a demographic bottleneck presents further challenges in breeding for disease resistance. A comparison with the homologue of closely related species M. javanensis revealed that amino acid replacement (nonsynonymous) but not silent (synonymous) differences have accumulated nonrandomly over the coding sequences of the receptors at the early stage of their phylogenetic split. The combined results from comparative analyses of nonsynonymous-to-synonymous polymorphisms showed that the receptor has undergone significant diversification in M. albus driven by adaptive selection likely after the genetic bottleneck. Some of the changes reported here have taken place in the structures mediating heterodimerization with co-receptor TLR2, ligand recognition, and/or formation of active signaling complex with adaptor, which highlighted key structural elements and strategies of TLR1 in arms race against exogenous challenges. The findings of this study will add to the knowledge base of genetic engineering and breeding for disease resistance in the eel.

A Cluster of Peronospora parasitica 13-like (NBS-LRR) Genes Is Associated with Powdery Mildew (Erysiphe polygoni) Resistance in Mungbean (Vigna radiata).

Powdery mildew (PM) caused by Erysiphe polygoni is an important foliar disease in mungbean (Vigna radiata). A previous study showed that QTL qPMRUM5-2 is a major locus for PM resistance in mungbean accession RUM5 (highly resistant). Bioinformatics analysis revealed that flanking markers of the qPMRUM5-2 covered a region of 1.93 Mb. In this study, we conducted fine mapping for the qPMRUM5-2 using the F2 population of 1156 plants of the cross between Chai Nat 60 (CN60; highly susceptible) and RUM5. PM resistance evaluation was performed under field conditions using F2:3 lines grown in three different environments. QTL analyses consistently located the qPMRUM5-2 to a 0.09 cm interval on linkage group 6 between InDel markers VrLG6-InDel05 and VrLG6-InDel10, which corresponded to a 135.0 kb region on chromosome 8 containing nine predicted genes of which five were NBS-LRR-type genes Recognition of Peronospora parasitica 13-like protein (RPP13L). Whole-genome re-sequencing of RUM5 and CN60 showed polymorphisms in four RPP13L genes predictively cause substantial amino acid changes, rendering them important candidate genes for PM resistance. The InDel markers VrLG6-InDel05 and VrLG6-InDel10 flanking to the qPMRUM5-2 would be useful for marker-assisted breeding of PM resistance in the mungbean.

Genetic loci associated with tissue-specific resistance to powdery mildew in octoploid strawberry (Fragaria × ananassa).

Powdery mildew is one of the most problematic diseases in strawberry production. To date, few commercial strawberry cultivars are deemed to have complete resistance and as such, an extensive spray programme must be implemented to control the pathogen. Here, a large-scale field experiment was used to determine the powdery mildew resistance status of leaf and fruit tissues across a diverse panel of strawberry genotypes. This phenotypic data was used to identify Quantitative Trait Nucleotides (QTN) associated with tissue-specific powdery mildew resistance. In total, six stable QTN were found to be associated with foliar resistance, with one QTN on chromosome 7D associated with a 61% increase in resistance. In contrast to the foliage results, there were no QTN associated with fruit disease resistance and there was a high level of resistance observed on strawberry fruit, with no genetic correlation observed between fruit and foliar symptoms, indicating a tissue-specific response. Beyond the identification of genetic loci, we also demonstrate that genomic selection can lead to rapid gains in foliar resistance across genotypes, with the potential to capture >50% of the genetic foliage resistance present in the population. To date, breeding of robust powdery mildew resistance in strawberry has been impeded by the quantitative nature of natural resistance and a lack of knowledge relating to the genetic control of the trait. These results address this shortfall, through providing the community with a wealth of information that could be utilized for genomic informed breeding, implementation of which could deliver a natural resistance strategy for combatting powdery mildew.

Mapping and characterization of rust resistance genes Lr53 and Yr35 introgressed from Aegilops species

Key messageThe rust resistance genes Lr53 and Yr35 were introgressed into bread wheat from Aegilops longissima or Aegilops sharonensis or their S-genome containing species and mapped to the telomeric region of chromosome arm 6BS.Wheat leaf and stripe rusts are damaging fungal diseases of wheat worldwide. Breeding for resistance is a sustainable approach to control these two foliar diseases. In this study, we used SNP analysis, sequence comparisons, and cytogenetic assays to determine that the chromosomal segment carrying Lr53 and Yr35 was originated from Ae.longissima or Ae. sharonensis or their derived species. In seedling tests, Lr53 conferred strong resistance against all five Chinese Pt races tested, and Yr35 showed effectiveness against Pst race CYR34 but susceptibility to race CYR32. Using a large population (3892 recombinant gametes) derived from plants homozygous for the ph1b mutation obtained from the cross 98M71 × CSph1b, both Lr53 and Yr35 were successfully mapped to a 6.03-Mb telomeric region of chromosome arm 6BS in the Chinese Spring reference genome v1.1. Co-segregation between Lr53 and Yr35 was observed within this large mapping population. Within the candidate region, several nucleotide-binding leucine-rich repeat genes and protein kinases were identified as candidate genes. Marker pku6B3127 was completely linked to both genes and accurately predicted the absence or presence of alien segment harboring Lr53 and Yr35 in 87 tetraploid and 149 hexaploid wheat genotypes tested. We developed a line with a smaller alien segment (< 6.03 Mb) to reduce any potential linkage drag and demonstrated that it conferred resistance levels similar to those of the original donor parent 98M71. The newly developed introgression line and closely linked PCR markers will accelerate the deployment of Lr53 and Yr35 in wheat breeding programs.

Development of a one‐step multiplex reverse transcription‐polymerase chain reaction and Luminex xTAG assay for the simultaneous detection of yellowing viruses infecting sugar beet

AbstractYellowing viruses are an increasing threat to sugar beet cultivation, due to limitations on insecticide usage and climate change. Virus detection, monitoring and resistance breeding are key to secure high sugar beet yields in the future. For this research, a one‐step multiplex reverse transcription (mRT)‐PCR method was designed to detect simultaneously beet mild yellowing virus, beet chlorosis virus, beet yellows virus (BYV), beet mosaic virus and turnip yellows virus. The addition of Luminex xTAG array technology was used as a follow‐up method to increase assay specificity. The one‐step mRT‐PCR was evaluated on 22 field samples with single and mixed virus infections. The xTAG assay works as expected both in a simplex and multiplex setting, except that BYV detection needs optimization in the multiplex setting. In the future, the Luminex xTAG assay would be an excellent method for the detection of beet yellowing viruses due to its high specificity and the potential to increase the number of targets.

Mapping and Omics Integration: Towards Precise Rice Disease Resistance Breeding.

Rice (Oryza sativa), as a staple crop feeding a significant portion of the global population, particularly in Asian countries, faces constant threats from various diseases jeopardizing global food security. A precise understanding of disease resistance mechanisms is crucial for developing resilient rice varieties. Traditional genetic mapping methods, such as QTL mapping, provide valuable insights into the genetic basis of diseases. However, the complex nature of rice diseases demands a holistic approach to gain an accurate knowledge of it. Omics technologies, including genomics, transcriptomics, proteomics, and metabolomics, enable a comprehensive analysis of biological molecules, uncovering intricate molecular interactions within the rice plant. The integration of various mapping techniques using multi-omics data has revolutionized our understanding of rice disease resistance. By overlaying genetic maps with high-throughput omics datasets, researchers can pinpoint specific genes, proteins, or metabolites associated with disease resistance. This integration enhances the precision of disease-related biomarkers with a better understanding of their functional roles in disease resistance. The improvement of rice breeding for disease resistance through this integration represents a significant stride in agricultural science because a better understanding of the molecular intricacies and interactions underlying disease resistance architecture leads to a more precise and efficient development of resilient and productive rice varieties. In this review, we explore how the integration of mapping and omics data can result in a transformative impact on rice breeding for enhancing disease resistance.

Study of cabbage antioxidant system response on early infection stage of Xanthomonas campestris pv. campestris

Black rot, caused by Xanthomonas campestris pv. campestris (Xcc) significantly affects the production of cabbage and other cruciferous vegetables. Plant antioxidant system plays an important role in pathogen invasion and is one of the main mechanisms underlying resistance to biological stress. Therefore, it is important to study the resistance mechanisms of the cabbage antioxidant system during the early stages of Xcc. In this study, 108 CFU/mL (OD600 = 0.1) Xcc race1 was inoculated on “zhonggan 11” cabbage using the spraying method. The effects of Xcc infection on the antioxidant system before and after Xcc inoculation (0, 1, 3, and 5 d) were studied by physiological indexes determination, transcriptome and metabolome analyses. We concluded that early Xcc infection can destroy the balance of the active oxygen metabolism system, increase the generation of free radicals, and decrease the scavenging ability, leading to membrane lipid peroxidation, resulting in the destruction of the biofilm system and metabolic disorders. In response to Xcc infection, cabbage clears a series of reactive oxygen species (ROS) produced during Xcc infection via various antioxidant pathways. The activities of antioxidant enzymes such as superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) increased after Xcc infection, and the ROS scavenging rate increased. The biosynthesis of non-obligate antioxidants, such as ascorbic acid (AsA) and glutathione (GSH), is also enhanced after Xcc infection. Moreover, the alkaloid and vitamin contents increased significantly after Xcc infection. We concluded that cabbage could resist Xcc invasion by maintaining the stability of the cell membrane system and improving the biosynthesis of antioxidant substances and enzymes after infection by Xcc. Our results provide theoretical basis and data support for subsequent research on the cruciferous vegetables resistance mechanism and breeding to Xcc.

Identification of new stable resistant sources and assessing agro-morphological performance of sponge gourd germplasm against Tomato Leaf curl New Delhi Virus incidence.

Tomato leaf curl New Delhi virus (TolCNDV) causes yellow mosaic disease, which poses a significant biotic constraint for sponge gourd cultivation, potentially resulting in crop loss of up to 100%. In the present investigation, 50 diverse genotypes were screened for 3 years under natural epiphytotic conditions. A subset of 20 genotypes was further evaluated across four different environments. The combined analysis of variance revealed a significant genotype × environment interaction. Eight genotypes consistently exhibited high and stable resistance in the preliminary screening and multi-environment testing. Furthermore, genotype plus genotype × environment interaction biplot analysis identified DSG-29 (G-3), DSG-7 (G-2), DSG-6 (G-1), and DSGVRL-18 (G-6) as the desirable genotypes, which have stable resistance and better yield potential even under diseased conditions. The genotype by yield × trait biplot analysis and multi-trait genotype-ideotype distance index analysis further validated the potential of these genotypes for combining higher yield and other desirable traits with higher resistance levels. Additionally, resistant genotypes exhibited higher activities of defense-related enzymes as compared to susceptible genotypes. Thus, genotypes identified in our study will serve as a valuable genetic resource for carrying out future resistance breeding programs in sponge gourd against ToLCNDV.

Allele mining for blast-resistance gene at Pi5 locus in rice

Rice plays a crucial role in global food security, serving as a staple for more than half of the world's population. Rice blast, caused by the fungus Magnaporthe oryzae, is one of the most devastating fungal diseases, resulting in substantial economic losses in terms of rice yield and grain quality. The resistance provided by individual blast resistance genes tends to become ineffective within a few years of extensive agricultural use due to the rapid evolution of the fungus. Therefore, continuous efforts in resistance breeding in rice are required to enrich the pool of new resistance genes and alleles. A large-scale screening of new blast resistance alleles was conducted across 2000 rice accessions from major rice-producing areas in China. Field trials were employed in two rice uniform blast nurseries located in Enshi and Yichang. Approximately 153 rice accessions showed at least moderate resistance to the rice blast. Sequence-based allele mining was used to identify the allelic variants of major rice blast resistance genes at the Pi5 locus of chromosome 9. Six novel alleles were identified from 64 accessions. Field tests at five locations, including Enshi, Yichang, Lvtian, Taojiang, and Yaan, and greenhouse inoculation using 33 blast strains from Hubei, Hunan, Guangzhou, and Sichuan, were employed to verify the resistance of these six alleles. Three near-isogenic lines (types 2, 4, and 6) were constructed and inoculated with 31 blast isolates from Heilongjiang to evaluate their blast resistance. Furthermore, bulk segregant analysis was used to confirm that Pi5-type2 and Pi5-type6 are dominant alleles in the analyzed populations. These novel alleles expand the allelic series, enriching the genetic resources for rice blast resistance breeding programs, especially in the north of China. Furthermore, they provide valuable insights into the molecular interactions between rice and rice blast.

Analyzing genetic diversity in luffa and developing a Fusarium wilt-susceptible linked SNP marker through a single plant genome-wide association (sp-GWAS) study

BackgroundLuffa (Luffa spp.) is an economically important crop of the Cucurbitaceae family, commonly known as sponge gourd or vegetable gourd. It is an annual cross-pollinated crop primarily found in the subtropical and tropical regions of Asia, Australia, Africa, and the Americas. Luffa serves not only as a vegetable but also exhibits medicinal properties, including anti-inflammatory, antidiabetic, and anticancer effects. Moreover, the fiber derived from luffa finds extensive applications in various fields such as biotechnology and construction. However, luffa Fusarium wilt poses a severe threat to its production, and existing control methods have proven ineffective in terms of cost-effectiveness and environmental considerations. Therefore, there is an urgent need to develop luffa varieties resistant to Fusarium wilt. Single-plant GWAS (sp-GWAS) has been demonstrated as a promising tool for the rapid and efficient identification of quantitative trait loci (QTLs) associated with target traits, as well as closely linked molecular markers.ResultsIn this study, a collection of 97 individuals from 73 luffa accessions including two major luffa species underwent single-plant GWAS to investigate luffa Fusarium wilt resistance. Utilizing the double digest restriction site associated DNA (ddRAD) method, a total of 8,919 high-quality single nucleotide polymorphisms (SNPs) were identified. The analysis revealed the potential for Fusarium wilt resistance in accessions from both luffa species. There are 6 QTLs identified from 3 traits, including the area under the disease progress curve (AUDPC), a putative disease-resistant QTL, was identified on the second chromosome of luffa. Within the region of linkage disequilibrium, a candidate gene homologous to LOC111009722, which encodes peroxidase 40 and is associated with disease resistance in Cucumis melo, was identified. Furthermore, to validate the applicability of the marker associated with resistance from sp-GWAS, an additional set of 21 individual luffa plants were tested, exhibiting 93.75% accuracy in detecting susceptible of luffa species L. aegyptiaca Mill.ConclusionIn summary, these findings give a hint of genome position that may contribute to luffa wild resistance to Fusarium and can be utilized in the future luffa wilt resistant breeding programs aimed at developing wilt-resistant varieties by using the susceptible-linked SNP marker.

Colletotrichum xishanense as a new etiological anthracnose agent on Fagopyrum gracilipes in Yunnan Province, China

Buckwheat (Fagopyrum spp.) is an important agricultural crop in some remote regions of China. In this study, two strains of Colletotrichum were isolated from brown and grey-white spots on the leaves of Fagopyrum gracilipes in Yunnan Province, China. Phylogenetic analyses inferred from combined ITS, act, chs-1, cal, gapdh, apmat, gs, and tub2 sequences revealed that these isolates are a new species, belonging to the C. gloeosporioides species complex and therefore we introduce as Colletotrichum xishanense. Pathogenicity tests indicated that C. xishanense infects not only herbaceous plant but also woody plant. Given the broader host range and stronger pathogenicity, it is time to focus on disease management and resistance breeding.

Advances in Okra (Abelmoschus esculentus L.) Breeding: Integrating Genomics for Enhanced Crop Improvement

Okra (Abelmoschus esculentus L.) holds significant importance as a vegetable crop, thriving in tropical and subtropical regions globally, especially in the warmer areas of temperate zones. Traditional breeding approaches tailored for self-pollinated crops have been utilized to enhance the genetic diversity of okra. These methods encompass various techniques such as plant introduction, pure line selection, hybridization combined with selection, mutation breeding, and heterosis breeding. Particularly in countries like India, pedigree selection and heterosis breeding have led to the development of numerous okra varieties and hybrids, significantly impacting local agricultural practices. Contemporary okra breeding focuses on traits crucial for optimal performance, including high yield potential, resistance to prevalent diseases like Yellow Vein Mosaic Virus (YVMV) and Okra Enation Leaf Curl Virus (OELCV), tolerance to sucking pests and borers, ease of harvest, deep green fruit coloration, and desirable plant architecture. Public sector institutions have played a pivotal role in introducing and disseminating improved okra varieties and hybrids, with more than 33 cultivars introduced in recent decades. Some of these varieties have demonstrated substantial improvements in okra production across India. This review offers an overview of the current state of okra breeding, encompassing genetic resources, cytogenetic relationships, breeding goals, varietal development processes, efforts in resistance breeding, biotechnological interventions, and future improvement strategies. By consolidating existing knowledge and highlighting ongoing research initiatives, this article aims to provide guidance and inspiration for further advancements in okra breeding and genomics, ultimately contributing to the sustainability and productivity of this essential vegetable crop.

In Vitro Collection for the Safe Storage of Grapevine Hybrids and Identification of the Presence of Plasmopara viticola Resistance Genes.

This paper focuses on the creation of an in vitro collection of grapevine hybrids from the breeding program of the Kazakh Scientific Research Institute of Fruit Growing and Viticulture and investigates the presence of Plasmopara viticola resistance mediated by Rpv3 and Rpv12 loci. We looked at the optimization of in vitro establishment using either shoots taken directly from field-grown plants or from budwood cuttings forced indoors. We further screened for the presence of endophyte contamination in the initiated explants and optimized the multiplication stage. Finally, the presence of the resistance loci against P. viticola was studied. The shoots initiated from the field-sourced explants were the more effective method of providing plant sources for in vitro initiation once all plant accessions met the goal of in vitro establishment. The concentration of phytohormones and the acidity of the culture medium have a great effect on the multiplication rate and the quality of in vitro stock cultures. Out of 17 grapevine accessions, 16 showed the presence of single or combined resistance loci against P. viticola. The grapevine accessions identified as carrying Rpv3 and Rpv12 alleles represent important genetic resources for disease resistance breeding programs. These accessions may further contribute to the creation of new elite cultivars of economic interest.

Fine mapping and analysis of a candidate gene controlling Phytophthora blight resistance in cucumber.

Cucumber blight is a destructive disease. The best way to control this disease is resistance breeding. This study focuses on disease resistance gene mapping and molecular marker development. We used the resistant cucumber, JSH, and susceptible cucumber, B80, as parents to construct F2 populations. Bulked segregant analysis (BSA) combined with specific length amplified fragment sequencing (SLAF-seq) were used, from which we developed cleaved amplified polymorphic sequence (CAPs) markers to map the resistance gene. Resistance in F2 individuals showed a segregation ratio of resistance:susceptibility close to 3:1. The gene in JSH resistant cucumber was mapped to an interval of 9.25 kb, and sequencing results for the three genes in the mapped region revealed three mutations at base sites 225, 302, and 591 in the coding region of Csa5G139130 between JSH and B80, but no mutations in coding regions of Csa5G139140 and Csa5G139150. The mutations caused changes in amino acids 75 and 101 of the protein encoded by Csa5G139130, suggesting that Csa5G139130 is the most likely resistance candidate gene. We developed a molecular marker, CAPs-4, as a closely linked marker for the cucumber blight resistance gene. This is the first report on mapping of a cucumber blight resistance gene and will provideg a useful marker for molecular breeding of cucumber resistance to Phytophthora blight.

Pecan secondary metabolites influenced the population of Zeuzera coffeae by affecting the structure and function of the larval gut microbiota.

The plant secondary metabolites (PSMs), as important plant resistance indicators, are important targets for screening plant insect resistance breeding. In this study, we aimed to investigate whether the population of Zeuzera coffeae (ZC) is affected by different varieties of Carya illinoinensis PSMs content. At the same time, the structure and function of the gut microbiome of ZC were also analyzed in relation to different pecan varieties. We counted the populations of ZC larvae in four pecan varieties and determined the content of four types of PSMs. The structure and function of the larval gut microbiota were studied in connection to the number of larvae and the content of PSMs. The relationships were investigated between larval number, larval gut microbiota, and PSM content. We found that the tannins, total phenolics, and total saponins of 4 various pecans PSMs stifled the development of the ZC larval population. The PSMs can significantly affect the diversity and abundance of the larval gut microbiota. Enrichment of ASV46 (Pararhizobium sp.), ASV994 (Olivibacter sp.), ASV743 (Rhizobium sp.), ASV709 (Rhizobium sp.), ASV671 (Luteolibacter sp.), ASV599 (Agrobacterium sp.), ASV575 (Microbacterium sp.), and ASV27 (Rhizobium sp.) in the gut of larvae fed on high-resistance cultivars was positively associated with their tannin, total saponin, and total phenolic content. The results of the gut microbiome functional prediction for larvae fed highly resistant pecan varieties showed that the enriched pathways in the gut were related to the breakdown of hazardous chemicals. Our findings provide further evidence that pecan PSMs influence the structure and function of the gut microbiota, which in turn affects the population stability of ZC. The study's findings can serve as a theoretical foundation for further work on selecting ZC-resistant cultivars and developing green management technology for ZC.

Breeding for potato cyst nematode resistance in Solanum tuberosum

AbstractTwo species of potato cyst nematodes (PCNs), Globodera rostochiensis (Woll.) and Globodera pallida (Stone), threaten potato (Solanum tuberosum L.) production worldwide. PCNs are remarkably persistent in soil and can reduce potato yield significantly. The most sustainable approach to PCN control is deploying resistant cultivars. This review focuses on the knowledge needed to conduct a successful PCN resistance breeding program, including identifying resistance sources in wild species, introgressing them into cultivated potato, and sifting through clones to identify a marketable potato.

Transcriptome analysis reveals various genes involved in the regulation of potato to late blight

BackgroundPotato (Solanum tuberosum L.) production is seriously threatened by the oomycete Phytophthora infestans (P. infestans). However, it remains unclear how the two potato cultivars, Q9 (moderately resistant) and Atl (susceptible), initiate distinct defense responses after inoculation with P. infestans. To uncover the underlying process, we investigated the dynamic gene expression profiles and the functions of the differentially expressed genes (DEGs).ResultsThe results showed that the numbers of up-regulated DEGs were 1345, 1063 and 1694 in Q9 and 272, 603 and 2554 in Atl at 1 day post inoculation (dpi), 3 dpi and 5 dpi, respectively. Meanwhile, the down-regulated DEGs were 1557, 1417 and 389 in Q9 and 114, 364 and 2528 in Atl simultaneously. KEGG enrichment analysis revealed that plant-pathogen interaction, phenylpropanoid biosynthesis and MAPK signaling pathway were significantly enriched in Q9 at the later stage. Furthermore, DEGs associated with plant-pathogen interaction and phenylpropanoid biosynthesis showed higher expression levels in Q9 compared to Atl, especially at the later stage. The expressions of eight DEGs were validated by quantitative real-time PCR (qRT-PCR), which further verified the accuracy of the transcriptomics analysis. In addition, DEGs that were exclusively up-regulated and down-regulated in Q9 were analyzed, which may contribute to the resistance of Q9. Transient expression analysis revealed that four DEGs, including StHP1, StMYB2, StHSP3 and StNAC5, exhibited increased tolerance to P. infestans, indicating a positive role in enhancing the resistance of Q9.ConclusionTherefore, the DEGs associated with plant-pathogen interaction, phenylpropanoid biosynthesis and MAPK signaling pathway were involved in regulating late blight, and the expression level of the related genes significantly increased in Q9. In addition, StHP1, StHSP3 and the transcription factors, including StMYB2 and StNAC5, played positive roles in improving the resistance of potato Q9 to P. infestans. These findings provide useful information for further understanding the molecular mechanism of potato resistance to late blight. Furthermore, our study identified novel resistance genes that can be used in resistance breeding and functional research.Graphical abstract

Impacts of Climate Change on Vector-Borne Diseases of Animals and Humans with Special Emphasis on Afghanistan

Vectors are organisms that transmit pathogenic microorganisms among animals and humans. Infections transmitted by the bites of blood-sucking arthropods are called vector-borne diseases (VBDs). This review highlights the impacts of climate change on the distribution, seasonal variation, and socioeconomic effects of VBDs in affected countries, especially Afghanistan. There is good enough evidence indicating that recent climate change has affected the interaction of the vector-pathogen-host cycle in many parts of the world. The emergence and re-emergence of bluetongue virus (BTV), Rift Valley Fever (RVF), lumpy skin disease (LSD), West Nile Virus (WNV), and malaria in new areas previously considered free of the diseases, and shift of seasonal occurrence of many VBDs in endemic areas, are the clear examples of climate change impacts on VDBs. Although significant progress has been made regarding VBD surveillance systems, diagnostic capacity, vaccine development, and vector control programs in resource-rich countries, failure in adaptation programs and ineffective mitigation strategies against VBDs in developing countries, especially in low and middle-income countries (LMICs), including Afghanistan facilitate widespread distribution of VBDs in these regions. Furthermore, developing drug resistance among the pathogens and their vectors makes the conditions more suitable for VBDs wide dispersion. Such situations cause severe health and socio-economic burdens to affected countries. Developing early-warning systems for detecting VBDs, identifying and developing resistant livestock species and breeds, and applying interceptive measures based on integrated research programs are crucial to effectively reduce the harmful impacts of VBDs on human and animal populations.