Pub Date : 2024-08-09DOI: 10.1094/phytofr-05-24-0054-a
L. Núñez-Rodríguez, Catherine L. Wram, Cedar Hesse, Inga A. Zasada
The bacterial endosymbiont, Wolbachia is known to be associated with different arthropods and only two genera of plant-parasitic nematodes, Pratylenchus and Radopholus. This effort employed a genome skimming approach to discover the presence of endosymbionts in a population of Heterodera humuli sequenced with PacBio long-read sequencing. Wolbachia was found associated with the nematode. The genome of this Wolbachia is 1,051,007 bp and has a GC% (32.6%) within the expected range for the genus. A phylogenetic analysis placed the Wolbachia strain from H. humuli in a clade with another nematode-associated Wolbachia strain reported in Texas, with a bootstrap value of 1. To our knowledge, this is the first published report of Wolbachia associated with H. humuli, expanding the known association of this endosymbiont to three genera of plant-parasitic nematodes. This finding will enhance sequence resources for further comparisons of Wolbachia diversity.
{"title":"Draft Genome Resource of a Wolbachia Endosymbiont in Heterodera humuli","authors":"L. Núñez-Rodríguez, Catherine L. Wram, Cedar Hesse, Inga A. Zasada","doi":"10.1094/phytofr-05-24-0054-a","DOIUrl":"https://doi.org/10.1094/phytofr-05-24-0054-a","url":null,"abstract":"The bacterial endosymbiont, Wolbachia is known to be associated with different arthropods and only two genera of plant-parasitic nematodes, Pratylenchus and Radopholus. This effort employed a genome skimming approach to discover the presence of endosymbionts in a population of Heterodera humuli sequenced with PacBio long-read sequencing. Wolbachia was found associated with the nematode. The genome of this Wolbachia is 1,051,007 bp and has a GC% (32.6%) within the expected range for the genus. A phylogenetic analysis placed the Wolbachia strain from H. humuli in a clade with another nematode-associated Wolbachia strain reported in Texas, with a bootstrap value of 1. To our knowledge, this is the first published report of Wolbachia associated with H. humuli, expanding the known association of this endosymbiont to three genera of plant-parasitic nematodes. This finding will enhance sequence resources for further comparisons of Wolbachia diversity.","PeriodicalId":508090,"journal":{"name":"PhytoFrontiers™","volume":"38 22","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141924068","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-26DOI: 10.1094/phytofr-06-24-0071-sc
Mukesh Jain, G. Minsavage, Naweena Thapa, Diana M. Horvath, Cyril Zipfel, Gloria A. Moore, Latanya C. Fisher, Vladimir Orbovic, Jeffrey B Jones
Arabidopsis thaliana pattern recognition receptor EFR recognizes and binds the bacterial PAMP EF-Tu and its highly conserved derived peptide elf18. Previous work revealed that the transgenic expression of EFR (and chimeric EFR::XA21) in several heterologous plant species, including in members of the Solanaceae and in sweet orange, confers broad-spectrum bacterial disease resistance. In this study, stable sweet orange (Citrus × sinensis) and grapefruit (C. × paradisi) transformants expressing EFR or EFR::XA21 were generated in an attempt to confer broad spectrum resistance to Xanthomonas citri subsp. citri (Xcc), causal agent of citrus canker, a serious disease of commercial citriculture. The transgene expression was confirmed via real-time quantitative reverse transcriptase PCR (RT-qPCR). Juvenile transgenic trees were challenged with Xcc (spray and pinprick inoculation) and evaluated for canker susceptibility and disease progression. Three independently transformed transgenic events (out of 19 total) displayed partial resistance to canker when spray-inoculated, and one line showed resistance when wound-inoculated. Surprisingly, when two mature transgenic lines were evaluated under field conditions and exposure to natural infection, both were found to be as susceptible as the wild-type under prevalent pathogen load. RT-qPCR data indicated a gradual decline and significant spatial variability in EFR expression in leaves excised from different branches of the same tree. The data presented here call for a need for evaluating different promoters for stable and long-term EFR expression in woody perennial species.
{"title":"Unstable Transgene Expression Affects Long-Term Efficacy of the Arabidopsis Immune Receptor EFR to Confer Quantitative Resistance to Citrus Canker Under Field Conditions","authors":"Mukesh Jain, G. Minsavage, Naweena Thapa, Diana M. Horvath, Cyril Zipfel, Gloria A. Moore, Latanya C. Fisher, Vladimir Orbovic, Jeffrey B Jones","doi":"10.1094/phytofr-06-24-0071-sc","DOIUrl":"https://doi.org/10.1094/phytofr-06-24-0071-sc","url":null,"abstract":"Arabidopsis thaliana pattern recognition receptor EFR recognizes and binds the bacterial PAMP EF-Tu and its highly conserved derived peptide elf18. Previous work revealed that the transgenic expression of EFR (and chimeric EFR::XA21) in several heterologous plant species, including in members of the Solanaceae and in sweet orange, confers broad-spectrum bacterial disease resistance. In this study, stable sweet orange (Citrus × sinensis) and grapefruit (C. × paradisi) transformants expressing EFR or EFR::XA21 were generated in an attempt to confer broad spectrum resistance to Xanthomonas citri subsp. citri (Xcc), causal agent of citrus canker, a serious disease of commercial citriculture. The transgene expression was confirmed via real-time quantitative reverse transcriptase PCR (RT-qPCR). Juvenile transgenic trees were challenged with Xcc (spray and pinprick inoculation) and evaluated for canker susceptibility and disease progression. Three independently transformed transgenic events (out of 19 total) displayed partial resistance to canker when spray-inoculated, and one line showed resistance when wound-inoculated. Surprisingly, when two mature transgenic lines were evaluated under field conditions and exposure to natural infection, both were found to be as susceptible as the wild-type under prevalent pathogen load. RT-qPCR data indicated a gradual decline and significant spatial variability in EFR expression in leaves excised from different branches of the same tree. The data presented here call for a need for evaluating different promoters for stable and long-term EFR expression in woody perennial species.","PeriodicalId":508090,"journal":{"name":"PhytoFrontiers™","volume":"48 26","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141799944","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-21DOI: 10.1094/phytofr-04-24-0043-a
Kishorekumar Reddy, Divya Kunda, Robert L. Gilbertson, Karen A. McDonald, S. Nandi, M. Sudarshana
Lettuce mosaic virus is a devastating pathogen that impacts commercial lettuce production. The complete genome sequence of an LMV isolate from a romaine lettuce plant (LMV-R) collected in 1,994 in the Salinas Valley of California was determined by RNA-seq, Sanger sequencing followed by 5′ RACE. The genome of LMV-R consists of 10,080 nucleotides and shares the highest nucleotide identity with the LMV isolate CL208 from Chile (97.2%) (GenBank accession KJ161176.1). LMV-R genome encodes for a single large polypeptide (UED15646) with putative proteolytic cleavage sites and showed 98.9% aa identity to a Turkish isolate (UEP55410) and, 98.71% to Chilean isolate (AIB00275). The sequence and phylogenetic analysis highlight the close association between LMV-R from the USA and CL208 of Chile, indicating that LMV-R might have been exchanged between North America and South America through international trade.
{"title":"First complete genome sequence resource of a Lettuce mosaic virus isolate from the United States of America","authors":"Kishorekumar Reddy, Divya Kunda, Robert L. Gilbertson, Karen A. McDonald, S. Nandi, M. Sudarshana","doi":"10.1094/phytofr-04-24-0043-a","DOIUrl":"https://doi.org/10.1094/phytofr-04-24-0043-a","url":null,"abstract":"Lettuce mosaic virus is a devastating pathogen that impacts commercial lettuce production. The complete genome sequence of an LMV isolate from a romaine lettuce plant (LMV-R) collected in 1,994 in the Salinas Valley of California was determined by RNA-seq, Sanger sequencing followed by 5′ RACE. The genome of LMV-R consists of 10,080 nucleotides and shares the highest nucleotide identity with the LMV isolate CL208 from Chile (97.2%) (GenBank accession KJ161176.1). LMV-R genome encodes for a single large polypeptide (UED15646) with putative proteolytic cleavage sites and showed 98.9% aa identity to a Turkish isolate (UEP55410) and, 98.71% to Chilean isolate (AIB00275). The sequence and phylogenetic analysis highlight the close association between LMV-R from the USA and CL208 of Chile, indicating that LMV-R might have been exchanged between North America and South America through international trade.","PeriodicalId":508090,"journal":{"name":"PhytoFrontiers™","volume":"58 16","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141818232","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-16DOI: 10.1094/phytofr-04-24-0042-r
Ana Maria Borda, J. Gelain, Minzheng Cai, Chao-Xi Luo, Guido Schnabel, James E. Faust
The use of conventional fungicides to control botrytis blight of ornamentals caused by Botrytis cinerea has its limitations due to increasing resistance to site-specific fungicides. Calcium propionate (CaP) has suppressive action against this disease and resistance in B. cinerea to CaP has not been reported. This study evaluated the efficacy of postharvest dip applications of 0.1% CaP (pH 6.0) to control botrytis blight in four cut rose (Rosa ×hybrida) cultivars and analyzed gene expression of CaP-treated rose petals. CaP reduced botrytis blight symptoms in rose ‘Alive’ but not in ‘Freedom’, ‘Momentum’, and ‘Orange Crush’, and no change in gene expression in ‘Orange Crush’ was detected following CaP treatment. Aerial spray applications at 0.1%, 0.2%, 0.3%, 0.4%, and 0.5% CaP made twice a week for 5 weeks caused minimal phytotoxicity damage to calendula (Calendula officinalis), carnation (Dianthus sp), dahlia (Dahlia sp), pansy (Viola ×wittrockiana), and snapdragon (Antirrhinum majus) leaves; however, CaP spray applications generated residues at all CaP concentrations in all species except for dahlia where no residue was observed. The results suggest that CaP will suppress botrytis blight in some but not all rose cultivars and establish a reference for phytotoxicity symptoms and visible CaP residues on ornamental plants.
由于对特定地点杀菌剂的抗药性不断增加，使用常规杀菌剂来控制观赏植物的灰霉病菌（Botrytis cinerea）有其局限性。丙酸钙（CaP）对这一病害具有抑制作用，但尚未有关于 B. cinerea 对 CaP 产生抗药性的报道。本研究评估了采后浸渍 0.1% CaP（pH 值为 6.0）对控制四个切花玫瑰（Rosa ×hybrida）品种的灰霉病的效果，并分析了经 CaP 处理的玫瑰花瓣的基因表达。CaP 能减轻玫瑰'Alive'的枯萎病症状，但不能减轻'Freedom'、'Momentum'和'Orange Crush'的枯萎病症状。空中喷洒 0.1%、0.2%、0.3%、0.4% 和 0.5%的 CaP，每周喷洒两次，连续喷洒 5 周，对金盏花（Calendula officinalis）、康乃馨（Dianthus sp）、大丽花（Dahlia sp）、三色堇（Viola ×wittrockiana）和金鱼草（Antirrhinum majus）叶片造成的植物毒性损害极小；但是，在所有 CaP 浓度下喷洒 CaP 都会在所有物种中产生残留，只有大丽花没有观察到残留。研究结果表明，CaP 可抑制某些（而非所有）玫瑰栽培品种的灰霉病，并为观赏植物上的植物毒性症状和可见 CaP 残留建立了参考标准。
{"title":"Effect of calcium propionate dip and spray applications on botrytis blight of ornamental plants","authors":"Ana Maria Borda, J. Gelain, Minzheng Cai, Chao-Xi Luo, Guido Schnabel, James E. Faust","doi":"10.1094/phytofr-04-24-0042-r","DOIUrl":"https://doi.org/10.1094/phytofr-04-24-0042-r","url":null,"abstract":"The use of conventional fungicides to control botrytis blight of ornamentals caused by Botrytis cinerea has its limitations due to increasing resistance to site-specific fungicides. Calcium propionate (CaP) has suppressive action against this disease and resistance in B. cinerea to CaP has not been reported. This study evaluated the efficacy of postharvest dip applications of 0.1% CaP (pH 6.0) to control botrytis blight in four cut rose (Rosa ×hybrida) cultivars and analyzed gene expression of CaP-treated rose petals. CaP reduced botrytis blight symptoms in rose ‘Alive’ but not in ‘Freedom’, ‘Momentum’, and ‘Orange Crush’, and no change in gene expression in ‘Orange Crush’ was detected following CaP treatment. Aerial spray applications at 0.1%, 0.2%, 0.3%, 0.4%, and 0.5% CaP made twice a week for 5 weeks caused minimal phytotoxicity damage to calendula (Calendula officinalis), carnation (Dianthus sp), dahlia (Dahlia sp), pansy (Viola ×wittrockiana), and snapdragon (Antirrhinum majus) leaves; however, CaP spray applications generated residues at all CaP concentrations in all species except for dahlia where no residue was observed. The results suggest that CaP will suppress botrytis blight in some but not all rose cultivars and establish a reference for phytotoxicity symptoms and visible CaP residues on ornamental plants.","PeriodicalId":508090,"journal":{"name":"PhytoFrontiers™","volume":" 19","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141832301","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-15DOI: 10.1094/phytofr-05-24-0056-r
Isabel Leal, N. Feau, Adnan Uzunovic, B. Foord, R. C. Hamelin
International trade in wood products is an important component of the global economy. However, wood and wood products may have pests associated with them that could be introduced into importing countries, posing phytosanitary risks, and leading to the implementation of regulatory restrictions that affect wood trade. The application of heat to kill wood-associated pests has been a successful phytosanitary method to reduce their spread. To evaluate the efficacy of wood heat treatment to kill fungal and fungus-like pathogens, the method of choice has been to grow organisms in cultures for subsequent identification. However, some plant pathogens can be difficult or impossible to grow in axenic cultures and a molecular method can still be useful for assessing pathogen viability after heat-treatment. RNA is a single stranded molecule that is responsible for the transcription of genes. Since it becomes rapidly unstable after cell death, it provides a measure of viability. We therefore designed and tested RNA-based molecular diagnostic assays targeting essential genes and assessed their presence after heat treatment in wood colonized by four Phytophthora species of phytosanitary concern (P. xmultiformis, P. cinnamomi, P. lateralis and P. ramorum) through reverse transcription and real-time polymerase chain reaction (RT-qPCR). Our assays differentiate between genomic and mRNA as the TaqMan probes span exon-intron junctions. We validated these RT-qPCR assays to assess heat treatment efficacy of Phytophthora-inoculated wood. These assays can be very useful tools to assess effectiveness of current and emerging phytosanitary wood treatments.
{"title":"A molecular method to assess viability of Phytophthora in infected wood following heat treatment","authors":"Isabel Leal, N. Feau, Adnan Uzunovic, B. Foord, R. C. Hamelin","doi":"10.1094/phytofr-05-24-0056-r","DOIUrl":"https://doi.org/10.1094/phytofr-05-24-0056-r","url":null,"abstract":"International trade in wood products is an important component of the global economy. However, wood and wood products may have pests associated with them that could be introduced into importing countries, posing phytosanitary risks, and leading to the implementation of regulatory restrictions that affect wood trade. The application of heat to kill wood-associated pests has been a successful phytosanitary method to reduce their spread. To evaluate the efficacy of wood heat treatment to kill fungal and fungus-like pathogens, the method of choice has been to grow organisms in cultures for subsequent identification. However, some plant pathogens can be difficult or impossible to grow in axenic cultures and a molecular method can still be useful for assessing pathogen viability after heat-treatment. RNA is a single stranded molecule that is responsible for the transcription of genes. Since it becomes rapidly unstable after cell death, it provides a measure of viability. We therefore designed and tested RNA-based molecular diagnostic assays targeting essential genes and assessed their presence after heat treatment in wood colonized by four Phytophthora species of phytosanitary concern (P. xmultiformis, P. cinnamomi, P. lateralis and P. ramorum) through reverse transcription and real-time polymerase chain reaction (RT-qPCR). Our assays differentiate between genomic and mRNA as the TaqMan probes span exon-intron junctions. We validated these RT-qPCR assays to assess heat treatment efficacy of Phytophthora-inoculated wood. These assays can be very useful tools to assess effectiveness of current and emerging phytosanitary wood treatments.","PeriodicalId":508090,"journal":{"name":"PhytoFrontiers™","volume":"35 7","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141649188","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-10DOI: 10.1094/phytofr-03-24-0017-r
Alireza Poursafar, Y. Leng, S. Zhong
Bipolaris sorokiniana (=Cochliobolus sativus) is an important fungal pathogen that causes spot blotch, common root rot and kernel blight in barley and wheat. In this study, we aimed to develop a CRISPR/Cas9-mediated approach for efficiently knocking out genes of B. sorokiniana. We first assessed the efficiency of Cas9/sgRNA combined with the split marker system for gene replacement. We designed sgRNAs to target a polyketide synthase gene (PKS1) that is required for melanin biosynthesis of the fungus. When the preassembled Cas9/gRNA ribonucleoproteins (RNPs) and the split hygromycin B resistance gene (HygB) fragments each harboring 449 bp upstream and 595 bp downstream flanking sequences of PKS1 were co-transformed into the protoplasts of B. sorokiniana, the number of transformants with the PKS1 gene replaced by the selection marker were significantly increased compared to the control without RNPs. We then used the RNPs with PCR-amplified HygB gene cassette carrying 40 bp or 60 bp arms homologous to the flanking sequences of the PKS1 target site for fungal transformation and showed that the RNPs significantly enhanced gene disruption efficiency through the short-homology recombination, and more gene knockout mutants were obtained with longer (60 bp) homologous arms than the shorter (40 bp) ones. Finally, we disrupted an uncharacterized non-ribosomal peptide synthetase (NRPS) gene (NPSx) in B. sorokiniana strain ND90Pr using the RNP-mediated gene knockout approach and showed the mutants lost virulence on barley cv. Bowman. The Cas9/sgRNA-mediated gene knockout method developed will facilitate large-scale functional genomics studies of B. sorokiniana.
Bipolaris sorokiniana（=Cochliobolus sativus）是一种重要的真菌病原体，可导致大麦和小麦斑点病、普通根腐病和核枯萎病。在本研究中，我们旨在开发一种 CRISPR/Cas9 介导的方法，以有效敲除 B. sorokiniana 的基因。我们首先评估了Cas9/sgRNA结合分裂标记系统进行基因替换的效率。我们设计了针对该真菌黑色素生物合成所需的多酮合成酶基因（PKS1）的 sgRNA。将预先组装好的 Cas9/gRNA 核糖核蛋白（RNPs）和各自包含 PKS1 上游 449 bp 和下游 595 bp 侧翼序列的土霉素 B 抗性基因（HygB）片段共同转化到 B. sorokiniana 的原生质体中，与不含 RNPs 的对照组相比，PKS1 基因被选择标记取代的转化子数量显著增加。然后，我们将 RNPs 与带有与 PKS1 目的位点侧翼序列同源的 40 bp 或 60 bp 臂的 PCR 扩增 HygB 基因盒一起用于真菌转化，结果表明 RNPs 通过短同源重组显著提高了基因破坏效率，长（60 bp）同源臂比短（40 bp）同源臂获得了更多的基因敲除突变体。最后，我们利用 RNP 介导的基因敲除方法破坏了 B. sorokiniana 菌株 ND90Pr 中一个未定性的非核糖体肽合成酶（NRPS）基因（NPSx），结果表明突变体对大麦 cv. Bowman 失去了毒力。Bowman 上失去毒性。所开发的 Cas9/sgRNA 介导的基因敲除方法将有助于对 B. sorokiniana 进行大规模的功能基因组学研究。
{"title":"Development of a CRISPR/Cas9-mediated gene knockout method for functional genomics of the barley spot blotch pathogen Bipolaris sorokiniana","authors":"Alireza Poursafar, Y. Leng, S. Zhong","doi":"10.1094/phytofr-03-24-0017-r","DOIUrl":"https://doi.org/10.1094/phytofr-03-24-0017-r","url":null,"abstract":"Bipolaris sorokiniana (=Cochliobolus sativus) is an important fungal pathogen that causes spot blotch, common root rot and kernel blight in barley and wheat. In this study, we aimed to develop a CRISPR/Cas9-mediated approach for efficiently knocking out genes of B. sorokiniana. We first assessed the efficiency of Cas9/sgRNA combined with the split marker system for gene replacement. We designed sgRNAs to target a polyketide synthase gene (PKS1) that is required for melanin biosynthesis of the fungus. When the preassembled Cas9/gRNA ribonucleoproteins (RNPs) and the split hygromycin B resistance gene (HygB) fragments each harboring 449 bp upstream and 595 bp downstream flanking sequences of PKS1 were co-transformed into the protoplasts of B. sorokiniana, the number of transformants with the PKS1 gene replaced by the selection marker were significantly increased compared to the control without RNPs. We then used the RNPs with PCR-amplified HygB gene cassette carrying 40 bp or 60 bp arms homologous to the flanking sequences of the PKS1 target site for fungal transformation and showed that the RNPs significantly enhanced gene disruption efficiency through the short-homology recombination, and more gene knockout mutants were obtained with longer (60 bp) homologous arms than the shorter (40 bp) ones. Finally, we disrupted an uncharacterized non-ribosomal peptide synthetase (NRPS) gene (NPSx) in B. sorokiniana strain ND90Pr using the RNP-mediated gene knockout approach and showed the mutants lost virulence on barley cv. Bowman. The Cas9/sgRNA-mediated gene knockout method developed will facilitate large-scale functional genomics studies of B. sorokiniana.","PeriodicalId":508090,"journal":{"name":"PhytoFrontiers™","volume":"49 s240","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141835371","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-14DOI: 10.1094/phytofr-02-24-0008-r
J. C. Koebernick, A. K. Hagan, M. Zaccaron, C. Escalante, A. L. Jacobson, K. L. Bowen, A. Strayer-Scherer, B. Heilsnis, S. Brown, E. J. Sikora, T. W. Allen, T. R. Faske, F. Bourland, J. K. Greene, A. S. Huseth, H. Kelly, R. C. Kemerait, D. Kerns, M. Mulvaney, P. P. Price, I. Small, S. Taylor, H. Wang, K. Conner
Cotton leafroll dwarf virus (CLRDV), transmitted by the cotton aphid (Aphis gossypii Glover), was first confirmed in upland cotton (Gossypium hirsutum L.) in Alabama, United States, in 2017. Subsequent observations of symptomatic plants followed by confirmation via reverse transcriptase PCR (RT-PCR) were made in neighboring states in 2018. To assess the distribution and incidence of CLRDV, and incidence of presumed symptoms across the southern cotton belt, a multidisciplinary team established sentinel plot survey sites at 16 experiment stations in 11 states stretching from Texas to Virginia and Tennessee to Florida beginning in 2019. Field trials were conducted over a three-year period using multiple cotton cultivars that were adjusted annually. Cotton plots were evaluated at each location by a single evaluator to attempt to correlate symptom severity across the cotton growing region with virus incidence in cotton plant tissues using RTPCR. Symptom incidence, based on visual estimation of plants in each plot with presumed symptoms, differed across the region and ranged from 0% to 75% with a low average from all locations of 11.4% in 2021 to an average high of 28.0% in 2020. Though symptom severity suggested the presence of CLRDV, there were instances where symptoms were observed but virus presence was not confirmed by PCR. CLRDV has since been confirmed from all locations, which suggests that it has become endemic in cotton production areas throughout the eastern range of the United States.
{"title":"Monitoring the distribution, incidence, and symptom expression associated with cotton leafroll dwarf virus in the southern United States using a sentinel plot system","authors":"J. C. Koebernick, A. K. Hagan, M. Zaccaron, C. Escalante, A. L. Jacobson, K. L. Bowen, A. Strayer-Scherer, B. Heilsnis, S. Brown, E. J. Sikora, T. W. Allen, T. R. Faske, F. Bourland, J. K. Greene, A. S. Huseth, H. Kelly, R. C. Kemerait, D. Kerns, M. Mulvaney, P. P. Price, I. Small, S. Taylor, H. Wang, K. Conner","doi":"10.1094/phytofr-02-24-0008-r","DOIUrl":"https://doi.org/10.1094/phytofr-02-24-0008-r","url":null,"abstract":"Cotton leafroll dwarf virus (CLRDV), transmitted by the cotton aphid (Aphis gossypii Glover), was first confirmed in upland cotton (Gossypium hirsutum L.) in Alabama, United States, in 2017. Subsequent observations of symptomatic plants followed by confirmation via reverse transcriptase PCR (RT-PCR) were made in neighboring states in 2018. To assess the distribution and incidence of CLRDV, and incidence of presumed symptoms across the southern cotton belt, a multidisciplinary team established sentinel plot survey sites at 16 experiment stations in 11 states stretching from Texas to Virginia and Tennessee to Florida beginning in 2019. Field trials were conducted over a three-year period using multiple cotton cultivars that were adjusted annually. Cotton plots were evaluated at each location by a single evaluator to attempt to correlate symptom severity across the cotton growing region with virus incidence in cotton plant tissues using RTPCR. Symptom incidence, based on visual estimation of plants in each plot with presumed symptoms, differed across the region and ranged from 0% to 75% with a low average from all locations of 11.4% in 2021 to an average high of 28.0% in 2020. Though symptom severity suggested the presence of CLRDV, there were instances where symptoms were observed but virus presence was not confirmed by PCR. CLRDV has since been confirmed from all locations, which suggests that it has become endemic in cotton production areas throughout the eastern range of the United States.","PeriodicalId":508090,"journal":{"name":"PhytoFrontiers™","volume":"50 17","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141339587","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-03DOI: 10.1094/phytofr-04-24-0039-r
A. Keinath
In South Carolina, the disease black spot on kale is caused by the fungi Alternaria brassicicola and A. japonica. Because all kale cultivars are presumed to be susceptible, organic producers may apply biofungicides to prevent or manage black spot. Microbial and biochemical biofungicides were tested in the greenhouse (12 products) and the field (ten products) against black spot caused by both Alternaria spp. on organically produced kale. Thereafter, three biofungicides (copper hydroxide, potassium silicate, and Reynoutria sachalinensis extract) were tested in the field on three kale cultivars. Although several biofungicides reduced black spot in the greenhouse compared to the water-treated control, no biofungicides did so in the field, even though they were applied preventatively before plants were inoculated. Biofungicides also did not increase weight of healthy leaves compared to the water-treated control in any field experiment. Conversely, two biofungicides that increased the severity and incidence of black spot in the greenhouse, B. amyloliquefaciens F727 and potassium bicarbonate, reduced weights of healthy leaves in the field. On average, curly kale cultivar Winterbor had fewer diseased leaves than curly kale cultivar Darkibor, and lacinato kale cultivar Toscano had fewer diseased leaves than curly kale. Winterbor also consistently produced greater healthy leaf weight than Darkibor. Biopesticides are not recommended against black spot on organic kale.
{"title":"Microbial and Biochemical Biofungicides Ineffective against Alternaria Black Spot on Organic Kale","authors":"A. Keinath","doi":"10.1094/phytofr-04-24-0039-r","DOIUrl":"https://doi.org/10.1094/phytofr-04-24-0039-r","url":null,"abstract":"In South Carolina, the disease black spot on kale is caused by the fungi Alternaria brassicicola and A. japonica. Because all kale cultivars are presumed to be susceptible, organic producers may apply biofungicides to prevent or manage black spot. Microbial and biochemical biofungicides were tested in the greenhouse (12 products) and the field (ten products) against black spot caused by both Alternaria spp. on organically produced kale. Thereafter, three biofungicides (copper hydroxide, potassium silicate, and Reynoutria sachalinensis extract) were tested in the field on three kale cultivars. Although several biofungicides reduced black spot in the greenhouse compared to the water-treated control, no biofungicides did so in the field, even though they were applied preventatively before plants were inoculated. Biofungicides also did not increase weight of healthy leaves compared to the water-treated control in any field experiment. Conversely, two biofungicides that increased the severity and incidence of black spot in the greenhouse, B. amyloliquefaciens F727 and potassium bicarbonate, reduced weights of healthy leaves in the field. On average, curly kale cultivar Winterbor had fewer diseased leaves than curly kale cultivar Darkibor, and lacinato kale cultivar Toscano had fewer diseased leaves than curly kale. Winterbor also consistently produced greater healthy leaf weight than Darkibor. Biopesticides are not recommended against black spot on organic kale.","PeriodicalId":508090,"journal":{"name":"PhytoFrontiers™","volume":"49 42","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141269741","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-21DOI: 10.1094/phytofr-01-24-0002-a
P. He, Wenjia Wang, Jiajia Zhang, Yuanju Zhang, W. Cui
The Bacillus velezensis strain HC-5, isolated from rhizosphere soil of ginger, exhibits effective biocontrol activity against ginger bacterial wilt. However, its genomic information has remained unexplored. This study presents the complete genome sequence of B. velezensis HC-5. The genome spans 4,237,244 bp and consists of 4,258 genes, with a total GC content of 45.85%. The HC-5 genome comprises 4,058 coding genes, 86 transfer RNAs, 27 ribosomal RNAs (rRNAs), 19 small RNAs (sRNAs), 70 interspersed repeats, and 74 tandem repeats. Moreover, we identified 10 gene clusters responsible for the biosynthesis of antibiotic compounds and 28 two-component systems associated with the bacterium's environmental adaptability. This genome sequence of B. velezensis HC-5 enhances our understanding of its biocontrol mechanisms and supports its potential development as an effective biocontrol agent for managing bacterial wilt in ginger production.
{"title":"Genome Sequence Resource of Bacillus velezensis strain HC-5, Revealing Its Potential as a Native Biological Control Agent against Ginger Bacterial Wilt","authors":"P. He, Wenjia Wang, Jiajia Zhang, Yuanju Zhang, W. Cui","doi":"10.1094/phytofr-01-24-0002-a","DOIUrl":"https://doi.org/10.1094/phytofr-01-24-0002-a","url":null,"abstract":"The Bacillus velezensis strain HC-5, isolated from rhizosphere soil of ginger, exhibits effective biocontrol activity against ginger bacterial wilt. However, its genomic information has remained unexplored. This study presents the complete genome sequence of B. velezensis HC-5. The genome spans 4,237,244 bp and consists of 4,258 genes, with a total GC content of 45.85%. The HC-5 genome comprises 4,058 coding genes, 86 transfer RNAs, 27 ribosomal RNAs (rRNAs), 19 small RNAs (sRNAs), 70 interspersed repeats, and 74 tandem repeats. Moreover, we identified 10 gene clusters responsible for the biosynthesis of antibiotic compounds and 28 two-component systems associated with the bacterium's environmental adaptability. This genome sequence of B. velezensis HC-5 enhances our understanding of its biocontrol mechanisms and supports its potential development as an effective biocontrol agent for managing bacterial wilt in ginger production.","PeriodicalId":508090,"journal":{"name":"PhytoFrontiers™","volume":"137 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141115125","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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