Pub Date : 2024-10-07DOI: 10.1094/PHYTO-01-24-0034-R
Lorena I Rangel, Nathan Wyatt, Isaac Courneya, Mari B Natwick, Gary A Secor, Viviana Rivera-Varas, Melvin D Bolton
Cercospora leaf spot, caused by the fungus Cercospora beticola, is the most destructive foliar disease of sugarbeet worldwide. Resistance to the sterol demethylation inhibitor (DMI) fungicide tetraconazole has been previously correlated with synonymous and nonsynonymous mutations in CbCyp51. Here, we extend these analyses to the DMI fungicides prothioconazole, difenoconazole, and mefentrifluconazole in addition to tetraconazole to confirm whether the synonymous and nonsynonymous mutations at amino acid positions 144 and 170 are associated with resistance to these fungicides. Nearly half of the 593 isolates of C. beticola collected in the Red River Valley of North Dakota and Minnesota in 2021 were resistant to all four DMIs. Another 20% were resistant to tetraconazole and prothioconazole but sensitive to difenoconazole and mefentrifluconazole. A total of 13% of isolates were sensitive to all DMIs tested. We found five CbCyp51 haplotypes and associated them with phenotypes to the four DMIs. The most predominant haplotype (E170_A/L144F_C) correlated with resistance to all four DMIs with up to 97.6% accuracy. The second most common haplotype (E170_A/L144) consisted of isolates associated with resistance phenotypes to tetraconazole and prothioconazole while also exhibiting sensitive phenotypes to difenoconazole and mefentrifluconazole with up to 98.4% accuracy. Quantitative PCR did not identify differences in CbCyp51 expression between haplotypes. This study offers an understanding of the importance of codon usage in fungicide resistance and provides crop management acuity for fungicide application decision-making.
{"title":"<i>CbCyp51</i>-Mediated Demethylation Inhibitor Resistance Is Modulated by Codon Bias.","authors":"Lorena I Rangel, Nathan Wyatt, Isaac Courneya, Mari B Natwick, Gary A Secor, Viviana Rivera-Varas, Melvin D Bolton","doi":"10.1094/PHYTO-01-24-0034-R","DOIUrl":"10.1094/PHYTO-01-24-0034-R","url":null,"abstract":"<p><p>Cercospora leaf spot, caused by the fungus Cercospora beticola, is the most destructive foliar disease of sugarbeet worldwide. Resistance to the sterol demethylation inhibitor (DMI) fungicide tetraconazole has been previously correlated with synonymous and nonsynonymous mutations in <i>CbCyp51</i>. Here, we extend these analyses to the DMI fungicides prothioconazole, difenoconazole, and mefentrifluconazole in addition to tetraconazole to confirm whether the synonymous and nonsynonymous mutations at amino acid positions 144 and 170 are associated with resistance to these fungicides. Nearly half of the 593 isolates of <i>C. beticola</i> collected in the Red River Valley of North Dakota and Minnesota in 2021 were resistant to all four DMIs. Another 20% were resistant to tetraconazole and prothioconazole but sensitive to difenoconazole and mefentrifluconazole. A total of 13% of isolates were sensitive to all DMIs tested. We found five <i>CbCyp51</i> haplotypes and associated them with phenotypes to the four DMIs. The most predominant haplotype (E170_A/L144F_C) correlated with resistance to all four DMIs with up to 97.6% accuracy. The second most common haplotype (E170_A/L144) consisted of isolates associated with resistance phenotypes to tetraconazole and prothioconazole while also exhibiting sensitive phenotypes to difenoconazole and mefentrifluconazole with up to 98.4% accuracy. Quantitative PCR did not identify differences in <i>CbCyp51</i> expression between haplotypes. This study offers an understanding of the importance of codon usage in fungicide resistance and provides crop management acuity for fungicide application decision-making.</p>","PeriodicalId":20410,"journal":{"name":"Phytopathology","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2024-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141617062","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-07DOI: 10.1094/PHYTO-08-24-0246-R
Xiaolin Zhang, Fenghua Liu, Dongxue Li, Di Guo, Yue Ma, Jing-Jiang Zhou, Delu Wang, Zhuo Chen
Tea leaf spot caused by Lasiodiplodia theobromae is a newly discovered fungal disease in southwest China. Due to a lack of knowledge of its epidemiology and control strategies, the disease has a marked impact on tea yield and quality. Pyriofenone is a new fungicide belonging to the aryl phenyl ketone fungicide group, which has shown marked efficacy in controlling various fungal diseases. However, its mechanism of action is not yet understood. This study found that pyriofenone exhibits strong in vitro inhibitory activity against various phytopathogenic fungi. Specifically, it showed strong inhibitory activity against L. theobromae, with a half-maximal effective concentration (EC50) value of 0.428 μg/ml determined by measuring mycelial growth rate. Morphological observations, using optical, scanning electron, and transmission electron microscopy, revealed that pyriofenone induces morphological abnormalities in L. theobromae hyphae. At lower doses, the hyphae became swollen, the distance between septa decreased, and the hyphal growth rate slowed. At higher doses and longer exposures, the hyphae collapsed. Transcriptomic and bioinformatic analyses indicated that pyriofenone can affect the expression of genes related to membrane transporters. Homology modeling suggested that pyriofenone may bind to a candidate target protein of the major facilitator superfamily (MFS) transporter, with a free binding energy of -7.1 kcal/mol. This study suggests that pyriofenone may potentially regulate the transport of metabolites in L. theobromae, thus affecting hyphal metabolism and interfering with hyphal growth. Pyriofenone exhibits in vitro inhibitory activity against various tea foliar pathogens and holds promise for future applications to the control of tea foliar diseases.
由Lasiodiplodia theobromae引起的茶叶叶斑病是中国西南地区新发现的一种真菌病害。由于对其流行病学和防治策略缺乏了解,该病害对茶叶的产量和质量造成了显著影响。Pyriofenone 是一种新型杀菌剂,属于芳基苯基酮类杀菌剂,对多种真菌病害有显著的防治效果。然而,人们对其作用机制尚不了解。本研究发现,吡蚜酮对多种植物病原真菌具有很强的体外抑制活性。具体来说,它对 L. theobromae 具有很强的抑制活性,通过测定菌丝生长速度,其半最大有效浓度(EC50)值为 0.428 μg/ml。使用光学、扫描电子和透射电子显微镜进行的形态学观察显示,吡蚜酮会诱导大叶菠萝褐藻菌丝出现形态异常。在较低剂量下,菌丝会肿胀,隔膜间距减小,菌丝生长速度减慢。在较高剂量和较长时间的暴露下,菌丝会塌陷。转录组学和生物信息学分析表明,吡蚜酮会影响与膜转运体有关的基因的表达。同源建模表明,吡蚜酮可能与主要促进剂超家族(MFS)转运体的候选靶蛋白结合,其自由结合能为-7.1 kcal/mol。这项研究表明,三苯甲酮可能会调节可可碱草菌代谢物的转运,从而影响菌体代谢并干扰菌体生长。Pyriofenone 对多种茶叶叶面病原体具有体外抑制活性,有望在未来应用于茶叶叶面病害的防治。
{"title":"Pyriofenone Interacts with the Major Facilitator Superfamily Transporter of Phytopathogenic Fungi to Potentially Control Tea Leaf Spot Caused by <i>Lasiodiplodia theobromae</i>.","authors":"Xiaolin Zhang, Fenghua Liu, Dongxue Li, Di Guo, Yue Ma, Jing-Jiang Zhou, Delu Wang, Zhuo Chen","doi":"10.1094/PHYTO-08-24-0246-R","DOIUrl":"https://doi.org/10.1094/PHYTO-08-24-0246-R","url":null,"abstract":"<p><p>Tea leaf spot caused by <i>Lasiodiplodia theobromae</i> is a newly discovered fungal disease in southwest China. Due to a lack of knowledge of its epidemiology and control strategies, the disease has a marked impact on tea yield and quality. Pyriofenone is a new fungicide belonging to the aryl phenyl ketone fungicide group, which has shown marked efficacy in controlling various fungal diseases. However, its mechanism of action is not yet understood. This study found that pyriofenone exhibits strong in vitro inhibitory activity against various phytopathogenic fungi. Specifically, it showed strong inhibitory activity against <i>L. theobromae</i>, with a half-maximal effective concentration (EC<sub>50</sub>) value of 0.428 μg/ml determined by measuring mycelial growth rate. Morphological observations, using optical, scanning electron, and transmission electron microscopy, revealed that pyriofenone induces morphological abnormalities in <i>L. theobromae</i> hyphae. At lower doses, the hyphae became swollen, the distance between septa decreased, and the hyphal growth rate slowed. At higher doses and longer exposures, the hyphae collapsed. Transcriptomic and bioinformatic analyses indicated that pyriofenone can affect the expression of genes related to membrane transporters. Homology modeling suggested that pyriofenone may bind to a candidate target protein of the major facilitator superfamily (MFS) transporter, with a free binding energy of -7.1 kcal/mol. This study suggests that pyriofenone may potentially regulate the transport of metabolites in <i>L. theobromae</i>, thus affecting hyphal metabolism and interfering with hyphal growth. Pyriofenone exhibits in vitro inhibitory activity against various tea foliar pathogens and holds promise for future applications to the control of tea foliar diseases.</p>","PeriodicalId":20410,"journal":{"name":"Phytopathology","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2024-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142381542","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-07DOI: 10.1094/PHYTO-06-24-0191-R
Ai Akami, Kenji Fukuda
The development of xylem embolism in 1-year-old stems of Japanese black pine (Pinus thunbergii) seedlings was monitored by compact magnetic resonance imaging (MRI) after inoculation with the pinewood nematode (Bursaphelenchus xylophilus). In parallel, the nematode distribution and population structure in the stems were examined by isolating the nematodes using the Baermann funnel technique. The vertical length and volume of massive embolisms in each seedling were strongly correlated with the maximum relative embolized area (REA) in stem cross-sections. Embolism development and nematode reproduction were not restricted to the inoculation site, as any portion of the stem could be the initial point of a population burst. The nematode population in the stem xylem was strongly correlated with the REA and with the circumferential proportion of cambial death in cross-sections monitored by MRI. The proportion of second-stage juveniles was also correlated with the REA in the xylem. In contrast, the nematode population in bark tissue was not correlated with either the REA or cambial death. These results suggested that nematode reproduction in the cambial zone is the key step in pine wilt disease, and second-stage juveniles were suggested to induce massive embolisms in the advanced stage of the disease.
在日本黑松(Pinus thunbergii)幼苗接种松材线虫(Bursaphelenchus xylophilus)后,通过紧凑型磁共振成像(MRI)监测了其 1 年生茎木质部栓塞的发展情况。与此同时,还利用 Baermann 漏斗技术分离线虫,研究线虫在茎中的分布和种群结构。每株幼苗中大量栓塞的垂直长度和体积与茎横截面上的最大相对栓塞面积(REA)密切相关。栓塞的发展和线虫的繁殖并不局限于接种点,因为茎干的任何部分都可能是种群爆发的初始点。在核磁共振成像监测的横截面上,茎木质部的线虫数量与REA和周向的韧皮部死亡比例密切相关。第二阶段幼虫的比例也与木质部的 REA 相关。相比之下,树皮组织中的线虫数量与 REA 或木质部死亡都没有关系。这些结果表明,线虫在韧皮部的繁殖是松树枯萎病的关键步骤,而第二阶段的幼虫被认为会在病害的晚期诱发大量栓塞。
{"title":"Relationship between the distribution of the pinewood nematode (<i>Bursaphelenchus xylophilus</i>) and the development of xylem embolism in the stems of Japanese black pine (<i>Pinus thunbergii</i>) seedlings monitored by magnetic resonance imaging.","authors":"Ai Akami, Kenji Fukuda","doi":"10.1094/PHYTO-06-24-0191-R","DOIUrl":"https://doi.org/10.1094/PHYTO-06-24-0191-R","url":null,"abstract":"<p><p>The development of xylem embolism in 1-year-old stems of Japanese black pine (<i>Pinus thunbergii</i>) seedlings was monitored by compact magnetic resonance imaging (MRI) after inoculation with the pinewood nematode (<i>Bursaphelenchus xylophilus</i>). In parallel, the nematode distribution and population structure in the stems were examined by isolating the nematodes using the Baermann funnel technique. The vertical length and volume of massive embolisms in each seedling were strongly correlated with the maximum relative embolized area (REA) in stem cross-sections. Embolism development and nematode reproduction were not restricted to the inoculation site, as any portion of the stem could be the initial point of a population burst. The nematode population in the stem xylem was strongly correlated with the REA and with the circumferential proportion of cambial death in cross-sections monitored by MRI. The proportion of second-stage juveniles was also correlated with the REA in the xylem. In contrast, the nematode population in bark tissue was not correlated with either the REA or cambial death. These results suggested that nematode reproduction in the cambial zone is the key step in pine wilt disease, and second-stage juveniles were suggested to induce massive embolisms in the advanced stage of the disease.</p>","PeriodicalId":20410,"journal":{"name":"Phytopathology","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2024-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142381543","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-07DOI: 10.1094/PHYTO-06-24-0189-R
Justin L Eagan, Evan R Digman, Martijn den Boon, Roberto Regalado, Mira S A Rawa, Christina M Hull, Nancy P Keller
Penicillium expansum is a major postharvest pathogen of apples, causing loss in fruits through tissue damage, as well as in apple products due to contamination with the mycotoxin patulin. During infections, patulin is a cultivar-dependent virulence factor that facilitates apple lesion development. Patulin also has characterized antimicrobial activity and is important for inhibiting other competitive phytopathogens, but the role of this inhibitory activity has not been investigated in the context of the apple microbiome. In our current study, we isolated 68 apple microbiota and characterized their susceptibility to P. expansum extracts. We found Gram-negative bacteria and Basidiomycete yeast to demonstrate largely patulin-specific growth inhibition compared to Gram-positive and Ascomycete isolates. From co-cultures, we identified a Hanseniaspora and Gluconobacter pairing that reduced P. expansum biomass and found that Hanseniaspora uvarum alone is sufficient to reduce apple disease progression in vivo. We investigated possible mechanisms of H. uvarum biocontrol activity and found modest inhibition on apple puree plates, as well as a trend toward lower patulin levels at the wound site. Active biocontrol activity required live yeast, which also were effective in controlling Botrytis cinerea apple infections. Lastly, we explored the breadth of H. uvarum biocontrol activity with over 30 H. uvarum isolates and found consistent inhibition of P. expansum apple disease.
扩张青霉是苹果采后的一种主要病原菌,会因组织损伤造成果实损失,也会因霉菌毒素棒曲霉素污染苹果产品而造成损失。在感染过程中,棒曲霉素是一种取决于栽培品种的毒力因子,可促进苹果病害的发展。棒曲霉素还具有抗菌活性,对抑制其他竞争性植物病原菌非常重要,但这种抑制活性在苹果微生物组中的作用尚未得到研究。在目前的研究中,我们分离了 68 个苹果微生物群,并描述了它们对扩张果实萃取物的敏感性。我们发现,与革兰氏阳性菌和子囊菌分离物相比,革兰氏阴性菌和担子菌酵母在很大程度上表现出抑制棒曲霉素特异性生长的作用。从共培养物中,我们发现了一种能减少扩张菌生物量的汉森氏菌和葡萄糖酵母菌配对,并发现仅汉森氏菌就足以减少苹果病害在体内的发展。我们研究了 H. uvarum 生物防治活性的可能机制,发现在苹果泥平板上有适度的抑制作用,而且伤口部位的棒曲霉素水平有降低的趋势。活跃的生物控制活性需要活酵母,而活酵母也能有效控制苹果灰霉病感染。最后,我们利用 30 多种 H. uvarum 分离物探索了 H. uvarum 生物防治活性的广度,发现它们对扩张果实瘤苹果病害具有一致的抑制作用。
{"title":"Patulin inhibition of specific apple microbiome members uncovers <i>Hanseniaspora uvarum</i> as a potential biocontrol agent.","authors":"Justin L Eagan, Evan R Digman, Martijn den Boon, Roberto Regalado, Mira S A Rawa, Christina M Hull, Nancy P Keller","doi":"10.1094/PHYTO-06-24-0189-R","DOIUrl":"https://doi.org/10.1094/PHYTO-06-24-0189-R","url":null,"abstract":"<p><p><i>Penicillium expansum</i> is a major postharvest pathogen of apples, causing loss in fruits through tissue damage, as well as in apple products due to contamination with the mycotoxin patulin. During infections, patulin is a cultivar-dependent virulence factor that facilitates apple lesion development. Patulin also has characterized antimicrobial activity and is important for inhibiting other competitive phytopathogens, but the role of this inhibitory activity has not been investigated in the context of the apple microbiome. In our current study, we isolated 68 apple microbiota and characterized their susceptibility to <i>P. expansum</i> extracts. We found Gram-negative bacteria and Basidiomycete yeast to demonstrate largely patulin-specific growth inhibition compared to Gram-positive and Ascomycete isolates. From co-cultures, we identified a <i>Hanseniaspora</i> and <i>Gluconobacter</i> pairing that reduced <i>P. expansum</i> biomass and found that <i>Hanseniaspora uvarum</i> alone is sufficient to reduce apple disease progression in vivo. We investigated possible mechanisms of <i>H. uvarum</i> biocontrol activity and found modest inhibition on apple puree plates, as well as a trend toward lower patulin levels at the wound site. Active biocontrol activity required live yeast, which also were effective in controlling <i>Botrytis cinerea</i> apple infections. Lastly, we explored the breadth of <i>H. uvarum</i> biocontrol activity with over 30 <i>H. uvarum</i> isolates and found consistent inhibition of <i>P. expansum</i> apple disease.</p>","PeriodicalId":20410,"journal":{"name":"Phytopathology","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2024-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142381527","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-07DOI: 10.1094/PHYTO-05-24-0172-R
Linkai Cui, Cong Wang, Mengqi Li, Yufeng Fang, Yanhong Hu
Exserohilum turcicum is a devastating fungal pathogen that infects both maize and sorghum, leading to severe leaf diseases of the two crops. According to host specificity, pathogenic isolates of E. turcicum are divided into two formae speciales, namely E. turcicum f. sp. zeae and E. turcicum f. sp. sorghi. To date, the molecular mechanism underlying the host specificity of E. turcicum is marginally known. In this study, the whole genomes of 60 E. turcicum isolates collected from both maize and sorghum were resequenced, which enabled identification of 233,022 single-nucleotide polymorphisms (SNPs) in total. Phylogenetic analysis indicated that all isolates are clustered into four genetic groups that have a close relationship with host source. This observation is validated by the result of principal component analysis. Analysis of population structure revealed that there is obvious genetic differentiation between two populations from maize and sorghum. Further analysis showed that 5,431 SNPs, including 612 nonsynonymous SNPs, are completely co-segregated with the host source. These nonsynonymous SNPs are located in 539 genes, among which 18 genes are predicted to encode secretory proteins, including six putative effector genes named SIX13-like, Ecp6, GH12, GH28-1, GH28-2, and CHP1. Sequence polymorphism analysis revealed various numbers of SNPs in the coding regions of these genes. These findings provide new insights into the molecular basis of host specificity in E. turcicum.
绿僵菌(Exserohilum turcicum)是一种毁灭性真菌病原体,可感染玉米和高粱,导致这两种作物严重的叶片病害。根据寄主特异性,E. turcicum 的病原分离物被分为两种特殊形式,即 E. turcicum f. sp. zeae 和 E. turcicum f. sp. sorghi。迄今为止,人们对E. turcicum宿主特异性的分子机制知之甚少。在这项研究中,对从玉米和高粱中收集到的 60 株 E. turcicum 分离物的全基因组进行了重新测序,共鉴定出 233 022 个单核苷酸多态性(SNPs)。系统发育分析表明,所有分离株都被分为四个基因组,它们与宿主来源关系密切。主成分分析的结果也验证了这一观点。种群结构分析表明,来自玉米和高粱的两个种群之间存在明显的遗传分化。进一步分析表明,5431 个 SNPs(包括 612 个非同义 SNPs)与宿主来源完全共分离。这些非同义 SNP 位于 539 个基因中,其中 18 个基因被预测编码分泌蛋白,包括 6 个假定效应基因,分别命名为 SIX13-like、Ecp6、GH12、GH28-1、GH28-2 和 CHP1。序列多态性分析显示,这些基因的编码区存在不同数量的 SNPs。这些发现为了解土耳其大肠杆菌宿主特异性的分子基础提供了新的视角。
{"title":"Whole-Genome Resequencing Reveals Significant Genetic Differentiation Between <i>Exserohilum turcicum</i> Populations from Maize and Sorghum and Candidate Effector Genes Related to Host Specificity.","authors":"Linkai Cui, Cong Wang, Mengqi Li, Yufeng Fang, Yanhong Hu","doi":"10.1094/PHYTO-05-24-0172-R","DOIUrl":"10.1094/PHYTO-05-24-0172-R","url":null,"abstract":"<p><p><i>Exserohilum turcicum</i> is a devastating fungal pathogen that infects both maize and sorghum, leading to severe leaf diseases of the two crops. According to host specificity, pathogenic isolates of <i>E. turcicum</i> are divided into two formae speciales, namely <i>E. turcicum</i> f. sp. <i>zeae</i> and <i>E. turcicum</i> f. sp. <i>sorghi</i>. To date, the molecular mechanism underlying the host specificity of <i>E. turcicum</i> is marginally known. In this study, the whole genomes of 60 <i>E. turcicum</i> isolates collected from both maize and sorghum were resequenced, which enabled identification of 233,022 single-nucleotide polymorphisms (SNPs) in total. Phylogenetic analysis indicated that all isolates are clustered into four genetic groups that have a close relationship with host source. This observation is validated by the result of principal component analysis. Analysis of population structure revealed that there is obvious genetic differentiation between two populations from maize and sorghum. Further analysis showed that 5,431 SNPs, including 612 nonsynonymous SNPs, are completely co-segregated with the host source. These nonsynonymous SNPs are located in 539 genes, among which 18 genes are predicted to encode secretory proteins, including six putative effector genes named <i>SIX13-like</i>, <i>Ecp6</i>, <i>GH12</i>, <i>GH28-1</i>, <i>GH28-2</i>, and <i>CHP1</i>. Sequence polymorphism analysis revealed various numbers of SNPs in the coding regions of these genes. These findings provide new insights into the molecular basis of host specificity in <i>E. turcicum</i>.</p>","PeriodicalId":20410,"journal":{"name":"Phytopathology","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2024-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141760573","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The bacterial canker of kiwifruit caused by Pseudomonas syringae pv. actinidiae (Psa) is the most devastating disease threatening the global kiwifruit production. This pathogen delivers multiple effector proteins into plant cells to resist plant immune responses and facilitate their survival. Here, we focused on the unique effector HopZ5 in Psa, which previously has been reported to have virulence functions. In this study, our results showed that HopZ5 could cause macroscopic cell death and trigger a serious immune response by agroinfiltration in Nicotiana benthamiana, along with upregulated expression of immunity-related genes and significant accumulation of reactive oxygen species and callose. Subsequently, we confirmed that HopZ5 interacted with the phosphoserine-binding protein GF14C in both the nonhost plant N. benthamiana (NbGF14C) and the host plant kiwifruit (AcGF14C), and silencing of NbGF14C compromised HopZ5-mediated cell death, suggesting that GF14C plays a crucial role in the detection of HopZ5. Further studies showed that overexpression of NbGF14C both markedly reduced the infection of Sclerotinia sclerotiorum and Phytophthora capsica in N. benthamiana, and overexpression of AcGF14C significantly enhanced the resistance of kiwifruit against Psa, indicating that GF14C positively regulates plant immunity. Collectively, our results revealed that the virulence effector HopZ5 could be recognized by plants and interact with GF14C to activate plant immunity.
{"title":"<i>Pseudomonas syringae</i> pv. <i>actinidiae</i> Unique Effector HopZ5 Interacts with GF14C to Trigger Plant Immunity.","authors":"Mingxia Zhou, Jinglong Zhang, Zhibo Zhao, Wei Liu, Zhiran Wu, Lili Huang","doi":"10.1094/PHYTO-09-23-0330-R","DOIUrl":"10.1094/PHYTO-09-23-0330-R","url":null,"abstract":"<p><p>The bacterial canker of kiwifruit caused by <i>Pseudomonas syringae</i> pv. <i>actinidiae</i> (<i>Psa</i>) is the most devastating disease threatening the global kiwifruit production. This pathogen delivers multiple effector proteins into plant cells to resist plant immune responses and facilitate their survival. Here, we focused on the unique effector HopZ5 in <i>Psa</i>, which previously has been reported to have virulence functions. In this study, our results showed that HopZ5 could cause macroscopic cell death and trigger a serious immune response by agroinfiltration in <i>Nicotiana benthamiana</i>, along with upregulated expression of immunity-related genes and significant accumulation of reactive oxygen species and callose. Subsequently, we confirmed that HopZ5 interacted with the phosphoserine-binding protein GF14C in both the nonhost plant <i>N. benthamiana</i> (NbGF14C) and the host plant kiwifruit (AcGF14C), and silencing of NbGF14C compromised HopZ5-mediated cell death, suggesting that GF14C plays a crucial role in the detection of HopZ5. Further studies showed that overexpression of NbGF14C both markedly reduced the infection of <i>Sclerotinia sclerotiorum</i> and <i>Phytophthora capsica</i> in <i>N. benthamiana</i>, and overexpression of AcGF14C significantly enhanced the resistance of kiwifruit against <i>Psa</i>, indicating that GF14C positively regulates plant immunity. Collectively, our results revealed that the virulence effector HopZ5 could be recognized by plants and interact with GF14C to activate plant immunity.</p>","PeriodicalId":20410,"journal":{"name":"Phytopathology","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2024-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141894112","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-04DOI: 10.1094/PHYTO-01-24-0017-R
Lifang Ye, Weigang Kuang, Lianhu Zhang, Yachun Lin, Yifan Zhang, Xiaotang Sun, Ruqiang Cui
Fusarium commune is the main pathogen of lotus rhizome rot, which causes the wilt of many plants. Histone acetyltransferase plays a critical part in the growth and virulence of fungi. In the present study, we identified an FcElp3 in F. commune homologous to histone acetyltransferase Elp3. We further constructed a mutant strain of F. commune to determine the function of FcElp3 in fungal growth and pathogenicity. The results showed that the deletion of FcElp3 resulted in reduced mycelial growth and sporulation. Compared with the wild type, the ΔFcElp3 strain showed more tolerance to osmotic stress and cell wall stress responses but was highly sensitive to oxidative stress. The subcellular localization results indicated that FcElp3 was distributed in both the cytoplasm and nucleus. Western blotting showed that FcElp3 was important for acetylation of H3K14 and H4K8. RNA sequencing analysis showed significant transcriptional changes in the ΔFcElp3 mutant, with 3,098 genes upregulated and 5,770 genes downregulated. Peroxisome was the most significantly enriched metabolic pathway for downregulated genes. This led to a significant decrease in the expression of the core transcription factor Fcap1 involved in the oxidative stress response. Pathogenicity tests revealed that the ΔFcElp3 mutant's pathogenicity on lotus was significantly decreased. Together, these findings clearly demonstrated that FcElp3 was involved in fungal growth, development, stress response, and pathogenicity via the direct regulation of multiple target genes.
{"title":"Functional Characterization of the Histone Acetyltransferase <i>FcElp3</i> in Lotus Rhizome Rot-Causing Fungus <i>Fusarium commune</i>.","authors":"Lifang Ye, Weigang Kuang, Lianhu Zhang, Yachun Lin, Yifan Zhang, Xiaotang Sun, Ruqiang Cui","doi":"10.1094/PHYTO-01-24-0017-R","DOIUrl":"10.1094/PHYTO-01-24-0017-R","url":null,"abstract":"<p><p><i>Fusarium commune</i> is the main pathogen of lotus rhizome rot, which causes the wilt of many plants. Histone acetyltransferase plays a critical part in the growth and virulence of fungi. In the present study, we identified an FcElp3 in <i>F. commune</i> homologous to histone acetyltransferase Elp3. We further constructed a mutant strain of <i>F. commune</i> to determine the function of FcElp3 in fungal growth and pathogenicity. The results showed that the deletion of FcElp3 resulted in reduced mycelial growth and sporulation. Compared with the wild type, the Δ<i>FcElp3</i> strain showed more tolerance to osmotic stress and cell wall stress responses but was highly sensitive to oxidative stress. The subcellular localization results indicated that FcElp3 was distributed in both the cytoplasm and nucleus. Western blotting showed that FcElp3 was important for acetylation of H3K14 and H4K8. RNA sequencing analysis showed significant transcriptional changes in the Δ<i>FcElp3</i> mutant, with 3,098 genes upregulated and 5,770 genes downregulated. Peroxisome was the most significantly enriched metabolic pathway for downregulated genes. This led to a significant decrease in the expression of the core transcription factor <i>Fcap1</i> involved in the oxidative stress response. Pathogenicity tests revealed that the Δ<i>FcElp3</i> mutant's pathogenicity on lotus was significantly decreased. Together, these findings clearly demonstrated that <i>FcElp3</i> was involved in fungal growth, development, stress response, and pathogenicity via the direct regulation of multiple target genes.</p>","PeriodicalId":20410,"journal":{"name":"Phytopathology","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2024-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141617064","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-03DOI: 10.1094/PHYTO-10-23-0402-KC
Elizabeth M Hellman, Thomas Turini, Cassandra L Swett
California is the primary processing tomato (Solanum lycopersicum) producer in the United States. Fusarium oxysporum f. sp. lycopercisi race 3 (Fol3), the cause of Fusarium wilt, is a major driver of yield losses. Fol3 has recently been observed causing disease in resistant cultivars (I-3 R-gene), often reported in association with high soil salinity. This study was undertaken to better understand the role of salinity in compromising resistance-based management of Fol3. Surveys established opportunity for salinity-Fol3-tomato interactions in 44% of commercial fields examined, with harmful soil salt levels up to 3.6 dS/m (P < 0.001), high sodium (P < 0.001), and high sodicity (sodium adsorption ratio > 13; P < 0.001). In controlled field studies of Fol3 in NaCl/CaCl2-treated soil, Fol3-resistant cultivars either only developed wilt under salt or only developed wilt above the industry non-hybrid threshold (2%) under salt across two trial years. The absence of yield differences indicates low to no economic impact of disease enhancement (P > 0.05). NaCl, CaCl2, and Na2SO4 had no effect on Fol3 propagule production in liquid agar versus water agar controls (P > 0.05), although CaCl2 increased propagule loads sevenfold versus ionic controls (polyethylene glycol) (P = 0.036). NaCl/CaCl2 (2:1) reduced propagule loads up to 65% versus no salt (P = 0.029) in soil with pathogen-infested tomato tissue. These results together establish the opportunity for salinity-Fol3-tomato interactions and potential for salt to influence the efficacy of resistant cultivar-based management-this does not appear to be primarily due to salt enhancement of pathogen populations, pointing to a yet-unexplored direct influence of salt on host resistance.
{"title":"Impacts of Increasing Soil Salinity on Genetic Resistance (<i>I-3</i> Gene)-Based Management of Fusarium Wilt (<i>Fusarium oxysporum</i> f. sp. <i>lycopercisi</i> Race 3) in California Processing Tomatoes.","authors":"Elizabeth M Hellman, Thomas Turini, Cassandra L Swett","doi":"10.1094/PHYTO-10-23-0402-KC","DOIUrl":"10.1094/PHYTO-10-23-0402-KC","url":null,"abstract":"<p><p>California is the primary processing tomato (<i>Solanum lycopersicum</i>) producer in the United States. <i>Fusarium oxysporum</i> f. sp. <i>lycopercisi</i> race 3 (Fol3), the cause of Fusarium wilt, is a major driver of yield losses. Fol3 has recently been observed causing disease in resistant cultivars (<i>I-3</i> R-gene), often reported in association with high soil salinity. This study was undertaken to better understand the role of salinity in compromising resistance-based management of Fol3. Surveys established opportunity for salinity-Fol3-tomato interactions in 44% of commercial fields examined, with harmful soil salt levels up to 3.6 dS/m (<i>P</i> < 0.001), high sodium (<i>P</i> < 0.001), and high sodicity (sodium adsorption ratio > 13; <i>P</i> < 0.001). In controlled field studies of Fol3 in NaCl/CaCl<sub>2</sub>-treated soil, Fol3-resistant cultivars either only developed wilt under salt or only developed wilt above the industry non-hybrid threshold (2%) under salt across two trial years. The absence of yield differences indicates low to no economic impact of disease enhancement (<i>P</i> > 0.05). NaCl, CaCl<sub>2</sub>, and Na<sub>2</sub>SO<sub>4</sub> had no effect on Fol3 propagule production in liquid agar versus water agar controls (<i>P</i> > 0.05), although CaCl<sub>2</sub> increased propagule loads sevenfold versus ionic controls (polyethylene glycol) (<i>P</i> = 0.036). NaCl/CaCl<sub>2</sub> (2:1) reduced propagule loads up to 65% versus no salt (<i>P</i> = 0.029) in soil with pathogen-infested tomato tissue. These results together establish the opportunity for salinity-Fol3-tomato interactions and potential for salt to influence the efficacy of resistant cultivar-based management-this does not appear to be primarily due to salt enhancement of pathogen populations, pointing to a yet-unexplored direct influence of salt on host resistance.</p>","PeriodicalId":20410,"journal":{"name":"Phytopathology","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2024-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141793096","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-03DOI: 10.1094/PHYTO-12-23-0491-R
Carlos C Góngora-Canul, Alexandria Volkening, Jorge Cuéllar, Lidia Calderón, Mariela Fernández-Campos, Da Young Lee, Jorge Salgado, Andres Cruz-Sancan, C D Cruz
Epidemiological studies to better understand wheat blast (WB) spatial and temporal patterns were conducted in three field environments in Bolivia between 2019 and 2020. The temporal dynamics of wheat leaf blast (WLB) and spike blast (WSB) were best described by the logistic model compared with the Gompertz and exponential models. The nonlinear logistic infection rates were higher under defined inoculation in experiments two and three than under undefined inoculation in experiment one, and they were also higher for WSB than for WLB. The onset of WLB began with a spatial clustering pattern according to autocorrelation analysis and Moran's index values, with higher severity and earlier onset for defined than for undefined inoculation until the last sampling time. The WSB onset did not start with a spatial clustering pattern; instead, it was detected later until the last sampling date across experiments, with higher severity and earlier onset for defined than for undefined inoculation. Maximum severity (Kmax) was 1.0 for WSB and less than 1.0 for WLB. Aggregation of WLB and WSB was higher for defined than for undefined inoculation. The directionality of hotspot development was similar for both WLB and WSB, mainly occurring concentrically for defined inoculation. Our results show no evidence of synchronized development but suggest a temporal and spatial progression of disease symptoms on wheat leaves and spikes. Thus, we recommend that monitoring and management of WB should be considered during early growth stages of wheat planted in areas of high risk.
{"title":"Effect of Initial Inoculum on the Temporal and Spatial Dynamics of Wheat Blast Under Field Conditions in Bolivia.","authors":"Carlos C Góngora-Canul, Alexandria Volkening, Jorge Cuéllar, Lidia Calderón, Mariela Fernández-Campos, Da Young Lee, Jorge Salgado, Andres Cruz-Sancan, C D Cruz","doi":"10.1094/PHYTO-12-23-0491-R","DOIUrl":"10.1094/PHYTO-12-23-0491-R","url":null,"abstract":"<p><p>Epidemiological studies to better understand wheat blast (WB) spatial and temporal patterns were conducted in three field environments in Bolivia between 2019 and 2020. The temporal dynamics of wheat leaf blast (W<sub>L</sub>B) and spike blast (W<sub>S</sub>B) were best described by the logistic model compared with the Gompertz and exponential models. The nonlinear logistic infection rates were higher under defined inoculation in experiments two and three than under undefined inoculation in experiment one, and they were also higher for W<sub>S</sub>B than for W<sub>L</sub>B. The onset of W<sub>L</sub>B began with a spatial clustering pattern according to autocorrelation analysis and Moran's index values, with higher severity and earlier onset for defined than for undefined inoculation until the last sampling time. The W<sub>S</sub>B onset did not start with a spatial clustering pattern; instead, it was detected later until the last sampling date across experiments, with higher severity and earlier onset for defined than for undefined inoculation. Maximum severity (<i>K<sub>max</sub></i>) was 1.0 for W<sub>S</sub>B and less than 1.0 for W<sub>L</sub>B. Aggregation of W<sub>L</sub>B and W<sub>S</sub>B was higher for defined than for undefined inoculation. The directionality of hotspot development was similar for both W<sub>L</sub>B and W<sub>S</sub>B, mainly occurring concentrically for defined inoculation. Our results show no evidence of synchronized development but suggest a temporal and spatial progression of disease symptoms on wheat leaves and spikes. Thus, we recommend that monitoring and management of WB should be considered during early growth stages of wheat planted in areas of high risk.</p>","PeriodicalId":20410,"journal":{"name":"Phytopathology","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2024-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141559505","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}