Weixia Wang, Andrew S. Taylor, Eden Tongson, Jacqueline Edwards, Niloofar Vaghefi, Peter K. Ades, Pedro W. Crous, Paul W. J. Taylor
Up to 32 Colletotrichum species have been reported to be associated with pre‐ or postharvest diseases of citrus globally, while in Australia, six species have been reported to cause citrus leaf and fruit disease. Twig or shoot dieback has recently been observed as an emerging disease in citrus orchards in Western Australia. Colletotrichum species were isolated from diseased twigs showing dieback (withertip) or lesions, with or without gummosis, collected from 12 varieties of orange, mandarin and lemon. Colletotrichum gloeosporioides sensu stricto, Colletotrichum karstii and Colletotrichum novae‐zelandiae were identified using a polyphasic approach that included multigene phylogenetic analysis using sequences of internal transcribed spacer and intervening 5.8S nrDNA (ITS), glyceraldehyde‐3‐phosphate dehydrogenase (gapdh), β‐tubulin (tub2), actin (act) and histone (his3) for isolates in the boninense species complex, and Apn2–Mat1–2 intergenic spacer and partial mating type (Mat1–2) (ApMat) and glutamine synthetase (gs) for isolates in the gloeosporioides species complex, as well as morphological characteristics. C. gloeosporioides was the most prevalent species associated with twig dieback in Western Australia, while C. novae‐zelandiae was reported for the first time in Australia. Pathogenicity tests on shoot twigs from lemon and orange trees confirmed C. gloeosporioides, C. karstii and C. novae‐zelandiae as the cause of twig dieback, with C. gloeosporioides being the most aggressive species. Knowledge of the species causing twig dieback and their lifestyle will assist the development of integrated control methods.
{"title":"Identification and pathogenicity of Colletotrichum species associated with twig dieback of citrus in Western Australia","authors":"Weixia Wang, Andrew S. Taylor, Eden Tongson, Jacqueline Edwards, Niloofar Vaghefi, Peter K. Ades, Pedro W. Crous, Paul W. J. Taylor","doi":"10.1111/ppa.13888","DOIUrl":"https://doi.org/10.1111/ppa.13888","url":null,"abstract":"Up to 32 <jats:italic>Colletotrichum</jats:italic> species have been reported to be associated with pre‐ or postharvest diseases of citrus globally, while in Australia, six species have been reported to cause citrus leaf and fruit disease. Twig or shoot dieback has recently been observed as an emerging disease in citrus orchards in Western Australia. <jats:italic>Colletotrichum</jats:italic> species were isolated from diseased twigs showing dieback (withertip) or lesions, with or without gummosis, collected from 12 varieties of orange, mandarin and lemon. <jats:italic>Colletotrichum gloeosporioides</jats:italic> sensu stricto, <jats:italic>Colletotrichum karstii</jats:italic> and <jats:italic>Colletotrichum novae‐zelandiae</jats:italic> were identified using a polyphasic approach that included multigene phylogenetic analysis using sequences of internal transcribed spacer and intervening 5.8S nrDNA (ITS), glyceraldehyde‐3‐phosphate dehydrogenase (<jats:italic>gapdh</jats:italic>), β‐tubulin (<jats:italic>tub2</jats:italic>), actin (<jats:italic>act</jats:italic>) and histone (<jats:italic>his3</jats:italic>) for isolates in the boninense species complex, and Apn2–Mat1–2 intergenic spacer and partial mating type (Mat1–2) (<jats:italic>ApMat</jats:italic>) and glutamine synthetase (<jats:italic>gs</jats:italic>) for isolates in the gloeosporioides species complex, as well as morphological characteristics. <jats:italic>C. gloeosporioides</jats:italic> was the most prevalent species associated with twig dieback in Western Australia, while <jats:italic>C. novae‐zelandiae</jats:italic> was reported for the first time in Australia. Pathogenicity tests on shoot twigs from lemon and orange trees confirmed <jats:italic>C. gloeosporioides</jats:italic>, <jats:italic>C. karstii</jats:italic> and <jats:italic>C. novae‐zelandiae</jats:italic> as the cause of twig dieback, with <jats:italic>C. gloeosporioides</jats:italic> being the most aggressive species. Knowledge of the species causing twig dieback and their lifestyle will assist the development of integrated control methods.","PeriodicalId":20075,"journal":{"name":"Plant Pathology","volume":"20 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140038078","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Plant resistance inducers (PRIs) are of increasing interest for disease control in sustainable viticulture, but their efficacy in vineyards is still under investigation. We studied the effects of four commercial PRIs, of natural and microbial origin, on the development of powdery mildew (PM) on grapevine leaves over a 3‐year period. Disease and sporulation severity were evaluated following the artificial inoculation of PRI‐treated leaves with Erysiphe necator conidia at 1, 3, 7 and 12 days after treatment (DAT). Laminarin (LAM) and cos‐oga (COS) were the most effective in reducing both disease (57.1% and 49.5%, respectively) and sporulation (85.3% and 90.2%, respectively) severity; the reduction in PM severity provided by cerevisane (CER) was lower (27%), and that of Pythium oligandrum (PYT) was intermediate (44.9%). LAM was effective from 1 DAT, while COS and PYT were more effective when E. necator was inoculated at 7 to 12 DAT. These results open new perspectives on how PRIs are used as single, preventative interventions performed 1 to 3 days before E. necator infection, depending on the product used. The effect of PRIs on the sporulation of E. necator colonies also suggests a broader and longer effect on PM epidemics.
植物抗性诱导剂（PRIs）在可持续葡萄栽培的病害控制中越来越受到关注，但其在葡萄园中的功效仍在研究之中。我们研究了四种天然和微生物来源的商业 PRI 对葡萄叶片白粉病（PM）发展的影响，为期 3 年。在处理后 1、3、7 和 12 天（DAT），在 PRI 处理过的叶片上人工接种新白粉病菌分生孢子后，对病害和孢子的严重程度进行了评估。在降低病害（分别为 57.1% 和 49.5%）和孢子化（分别为 85.3% 和 90.2%）严重程度方面，氨基甲酸乙酯（LAM）和复方阿糖胞苷（COS）的效果最好；谷维素（CER）对 PM 严重程度的降低率较低（27%），而寡糖百菌清（PYT）的降低率介于两者之间（44.9%）。LAM 从 1 DAT 开始有效，而 COS 和PYT 在 7 至 12 DAT 接种 E. necator 时更有效。这些结果为如何将 PRIs 用作坏死杆菌感染前 1 到 3 天的单一预防性干预措施提供了新的视角，具体取决于所使用的产品。PRIs 对坏死杆菌菌落孢子化的影响还表明，它对 PM 流行病的影响范围更广、时间更长。
{"title":"Pre‐infection efficacy of resistance inducers against grapevine powdery mildew","authors":"Othmane Taibi, Giorgia Fedele, Vittorio Rossi","doi":"10.1111/ppa.13886","DOIUrl":"https://doi.org/10.1111/ppa.13886","url":null,"abstract":"Plant resistance inducers (PRIs) are of increasing interest for disease control in sustainable viticulture, but their efficacy in vineyards is still under investigation. We studied the effects of four commercial PRIs, of natural and microbial origin, on the development of powdery mildew (PM) on grapevine leaves over a 3‐year period. Disease and sporulation severity were evaluated following the artificial inoculation of PRI‐treated leaves with <jats:italic>Erysiphe necator</jats:italic> conidia at 1, 3, 7 and 12 days after treatment (DAT). Laminarin (LAM) and cos‐oga (COS) were the most effective in reducing both disease (57.1% and 49.5%, respectively) and sporulation (85.3% and 90.2%, respectively) severity; the reduction in PM severity provided by cerevisane (CER) was lower (27%), and that of <jats:italic>Pythium oligandrum</jats:italic> (PYT) was intermediate (44.9%). LAM was effective from 1 DAT, while COS and PYT were more effective when <jats:italic>E</jats:italic>. <jats:italic>necator</jats:italic> was inoculated at 7 to 12 DAT. These results open new perspectives on how PRIs are used as single, preventative interventions performed 1 to 3 days before <jats:italic>E</jats:italic>. <jats:italic>necator</jats:italic> infection, depending on the product used. The effect of PRIs on the sporulation of <jats:italic>E</jats:italic>. <jats:italic>necator</jats:italic> colonies also suggests a broader and longer effect on PM epidemics.","PeriodicalId":20075,"journal":{"name":"Plant Pathology","volume":"4 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-02-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140004610","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Anthony Bryan, Andrey Korolev, Susan Bergmann, Willem H. P. Boshoff, Kerstin Flath, Annemarie F. Justesen, Philipp Schulz, Botma Visser, Diane G. O. Saunders
Stem rust is a serious disease of many gramineous plants including small grain staples such as wheat, barley, rye and triticale. Separate formae speciales (ff. spp.) of the causal fungus, Puccinia graminis, predominantly infect certain host plant genera. However, despite these taxonomic subdivisions, many P. graminis ff. spp. are genetically too similar to distinguish using existing genetic markers. For those infecting cereals, this is particularly challenging for P. graminis f. sp. tritici (Pgt) and P. graminis f. sp. secalis (Pgs). Herein we harnessed newly available genomic data for 39 Pgt and Pgs isolates and identified four regions of structural variation that were used to design four simple PCR‐based assays to distinguish the aforementioned formae speciales. These genomic regions display large presence/absence variation between Pgt and Pgs isolates, and yet a high degree of sequence conservation within shared neighbouring regions, facilitating primer design. We also confirmed lack of amplification in host plant genera analysed, which included assessment of the shared alternate host of Pgt and Pgs, Berberis vulgaris. Accurate classification of P. graminis ff. spp. infections on B. vulgaris is exceptionally valuable to rapidly define plants harbouring P. graminis inoculum when adjacent to cereal crops. Finally, we demonstrated utility of these four genetic markers to correctly distinguish a genetically diverse array of Pgt and Pgs isolates. This strategy could now be readily applied to other pathogens of interest, which will be of increasing value as genomic resources continue to rapidly expand for many key biotic threats to agricultural productivity.
{"title":"Comparative genomics identifies genetic markers linked to structural variations that differentiate Puccinia graminis tritici and secalis formae speciales","authors":"Anthony Bryan, Andrey Korolev, Susan Bergmann, Willem H. P. Boshoff, Kerstin Flath, Annemarie F. Justesen, Philipp Schulz, Botma Visser, Diane G. O. Saunders","doi":"10.1111/ppa.13890","DOIUrl":"https://doi.org/10.1111/ppa.13890","url":null,"abstract":"Stem rust is a serious disease of many gramineous plants including small grain staples such as wheat, barley, rye and triticale. Separate <jats:italic>formae speciales</jats:italic> (ff. spp.) of the causal fungus, <jats:italic>Puccinia graminis</jats:italic>, predominantly infect certain host plant genera. However, despite these taxonomic subdivisions, many <jats:italic>P</jats:italic>. <jats:italic>graminis</jats:italic> ff. spp. are genetically too similar to distinguish using existing genetic markers. For those infecting cereals, this is particularly challenging for <jats:italic>P</jats:italic>. <jats:italic>graminis</jats:italic> f. sp. <jats:italic>tritici</jats:italic> (Pgt) and <jats:italic>P</jats:italic>. <jats:italic>graminis</jats:italic> f. sp. <jats:italic>secalis</jats:italic> (Pgs). Herein we harnessed newly available genomic data for 39 Pgt and Pgs isolates and identified four regions of structural variation that were used to design four simple PCR‐based assays to distinguish the aforementioned <jats:italic>formae speciales</jats:italic>. These genomic regions display large presence/absence variation between Pgt and Pgs isolates, and yet a high degree of sequence conservation within shared neighbouring regions, facilitating primer design. We also confirmed lack of amplification in host plant genera analysed, which included assessment of the shared alternate host of Pgt and Pgs, <jats:italic>Berberis vulgaris</jats:italic>. Accurate classification of <jats:italic>P</jats:italic>. <jats:italic>graminis</jats:italic> ff. spp. infections on <jats:italic>B</jats:italic>. <jats:italic>vulgaris</jats:italic> is exceptionally valuable to rapidly define plants harbouring <jats:italic>P</jats:italic>. <jats:italic>graminis</jats:italic> inoculum when adjacent to cereal crops. Finally, we demonstrated utility of these four genetic markers to correctly distinguish a genetically diverse array of Pgt and Pgs isolates. This strategy could now be readily applied to other pathogens of interest, which will be of increasing value as genomic resources continue to rapidly expand for many key biotic threats to agricultural productivity.","PeriodicalId":20075,"journal":{"name":"Plant Pathology","volume":"53 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-02-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140004821","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Bacterial wilt caused by Ralstonia solanacearum is a destructive plant disease, particularly in potato (Solanum tuberosum). R. solanacearum deploys a diverse and potent arsenal of type III effectors to inhibit the plant immune system. However, the understanding of individual effectors promoting susceptibility in host plants and interfering with plant immunity responses is still limited. Here, we demonstrated that the type III effector RipV1 functioned as a novel E3 ubiquitin ligase (NEL) effector and exhibited E3 ubiquitin ligase activity in vitro. Transient expression of RipV1 suppressed plant pathogen‐associated molecular pattern (PAMP)‐triggered immunity (PTI) responses in Nicotiana benthamiana, such as the expression of PTI‐related genes and the reactive oxygen species (ROS) burst. Prolonged expression of RipV1 induced cell death in N. benthamiana leaves. Notably, mutating the conserved cysteine residue of RipV1 abolished its E3 ligase activity and its ability to suppress plant PTI responses. This study also revealed the indispensability of RipV1 for R. solanacearum's full virulence in potato. Transgenic potato plants overexpressing ripV1 but not the catalytic mutant ripV1‐C444A displayed enhanced susceptibility to R. solanacearum. RipV1 was observed to localize specifically to the plant plasma membrane, with its N‐terminus being pivotal in determining this localization. These findings showcase that RipV1 acts as a NEL effector and contributes to R. solanacearum virulence by suppressing plant PTI responses through its E3 activity.
由 Ralstonia solanacearum 引起的细菌枯萎病是一种破坏性植物病害，尤其是马铃薯（Solanum tuberosum）。R. solanacearum 部署了多种有效的 III 型效应物来抑制植物免疫系统。然而，人们对促进寄主植物易感性和干扰植物免疫反应的单个效应因子的了解仍然有限。在这里，我们证明了 III 型效应物 RipV1 作为一种新型 E3 泛素连接酶（NEL）效应物，在体外表现出 E3 泛素连接酶活性。RipV1 的瞬时表达抑制了烟曲霉中植物病原体相关分子模式（PAMP）触发的免疫（PTI）反应，如 PTI 相关基因的表达和活性氧（ROS）猝灭。RipV1 的长期表达会诱导 N. benthamiana 叶子中的细胞死亡。值得注意的是，突变 RipV1 的保守半胱氨酸残基会削弱其 E3 连接酶活性及其抑制植物 PTI 反应的能力。这项研究还揭示了 R. solanacearum 在马铃薯中的全面毒力离不开 RipV1。过表达 ripV1 而非催化突变体 ripV1-C444A 的转基因马铃薯植株对 R. solanacearum 的易感性增强。据观察，RipV1 能特异性地定位在植物质膜上，其 N 端是决定这种定位的关键。这些研究结果表明，RipV1 是一种 NEL 效应子，通过其 E3 活性抑制植物 PTI 反应，从而增强了茄枯菌的毒力。
{"title":"The Ralstonia solanacearum effector RipV1 acts as a novel E3 ubiquitin ligase to suppress plant PAMP‐triggered immunity responses and promote susceptibility in potato","authors":"Dong Cheng, Dan Zhou, Yuqi Wang, Yudan Wang, Huishan Qiu, Xiaodan Tan, Bingsen Wang, Mengshu Huang, Botao Song, Huilan Chen","doi":"10.1111/ppa.13885","DOIUrl":"https://doi.org/10.1111/ppa.13885","url":null,"abstract":"Bacterial wilt caused by <jats:italic>Ralstonia solanacearum</jats:italic> is a destructive plant disease, particularly in potato (<jats:italic>Solanum tuberosum</jats:italic>). <jats:italic>R</jats:italic>. <jats:italic>solanacearum</jats:italic> deploys a diverse and potent arsenal of type III effectors to inhibit the plant immune system. However, the understanding of individual effectors promoting susceptibility in host plants and interfering with plant immunity responses is still limited. Here, we demonstrated that the type III effector RipV1 functioned as a novel E3 ubiquitin ligase (NEL) effector and exhibited E3 ubiquitin ligase activity in vitro. Transient expression of RipV1 suppressed plant pathogen‐associated molecular pattern (PAMP)‐triggered immunity (PTI) responses in <jats:italic>Nicotiana benthamiana</jats:italic>, such as the expression of PTI‐related genes and the reactive oxygen species (ROS) burst. Prolonged expression of RipV1 induced cell death in <jats:italic>N</jats:italic>. <jats:italic>benthamiana</jats:italic> leaves. Notably, mutating the conserved cysteine residue of RipV1 abolished its E3 ligase activity and its ability to suppress plant PTI responses. This study also revealed the indispensability of RipV1 for <jats:italic>R</jats:italic>. <jats:italic>solanacearum</jats:italic>'s full virulence in potato. Transgenic potato plants overexpressing <jats:italic>ripV1</jats:italic> but not the catalytic mutant <jats:italic>ripV1‐C444A</jats:italic> displayed enhanced susceptibility to <jats:italic>R</jats:italic>. <jats:italic>solanacearum</jats:italic>. RipV1 was observed to localize specifically to the plant plasma membrane, with its N‐terminus being pivotal in determining this localization. These findings showcase that RipV1 acts as a NEL effector and contributes to <jats:italic>R</jats:italic>. <jats:italic>solanacearum</jats:italic> virulence by suppressing plant PTI responses through its E3 activity.","PeriodicalId":20075,"journal":{"name":"Plant Pathology","volume":"29 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140004608","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hiroyuki Suzuki, Seonju Marincowitz, Jolanda Roux, Trudy Paap, Brenda D. Wingfield, Michael J. Wingfield
Fungi in the Cryphonectriaceae are important canker pathogens of woody shrubs and trees in the Melastomataceae and Myrtaceae (Myrtales). During 2021 disease surveys in KwaZulu-Natal (South Africa) plantations, a serious stem canker disease was discovered on species of Eucalyptus and Corymbia. The cankers had structures on their surfaces typical of fungi in the Cryphonectriaceae. The aims of the study were to identify the fungus associated with the disease and to test its pathogenicity. Morphological characteristics of both sexual and asexual structures and phylogenetic analyses based on partial sequences of the conserved nuclear large subunit (LSU) ribosomal DNA, the internal transcribed spacer (ITS) regions including the 5.8S gene of the ribosomal DNA operon, and two β-tubulin (BT1/BT2) regions were used for identification purposes. Phylogenetic analyses of the sequence data and morphological characteristics supported the establishment of a new genus in the Cryphonectriaceae, for which the name Xanthoporthe myrticola gen. et sp. nov. is provided. Pathogenicity trials showed that isolates were pathogenic on tested Eucalyptus grandis and hybrids as well as Corymbia henryi. The results suggest that this is an emerging pathogen that could influence the sustainability of plantation forestry in South Africa.
{"title":"A new genus and species of Cryphonectriaceae causing stem cankers on plantation eucalypts in South Africa","authors":"Hiroyuki Suzuki, Seonju Marincowitz, Jolanda Roux, Trudy Paap, Brenda D. Wingfield, Michael J. Wingfield","doi":"10.1111/ppa.13883","DOIUrl":"https://doi.org/10.1111/ppa.13883","url":null,"abstract":"Fungi in the Cryphonectriaceae are important canker pathogens of woody shrubs and trees in the Melastomataceae and Myrtaceae (Myrtales). During 2021 disease surveys in KwaZulu-Natal (South Africa) plantations, a serious stem canker disease was discovered on species of <i>Eucalyptus</i> and <i>Corymbia</i>. The cankers had structures on their surfaces typical of fungi in the Cryphonectriaceae. The aims of the study were to identify the fungus associated with the disease and to test its pathogenicity. Morphological characteristics of both sexual and asexual structures and phylogenetic analyses based on partial sequences of the conserved nuclear large subunit (LSU) ribosomal DNA, the internal transcribed spacer (ITS) regions including the 5.8S gene of the ribosomal DNA operon, and two β-tubulin (<i>BT1</i>/<i>BT2</i>) regions were used for identification purposes. Phylogenetic analyses of the sequence data and morphological characteristics supported the establishment of a new genus in the Cryphonectriaceae, for which the name <i>Xanthoporthe myrticola</i> gen. et sp. nov. is provided. Pathogenicity trials showed that isolates were pathogenic on tested <i>Eucalyptus grandis</i> and hybrids as well as <i>Corymbia henryi</i>. The results suggest that this is an emerging pathogen that could influence the sustainability of plantation forestry in South Africa.","PeriodicalId":20075,"journal":{"name":"Plant Pathology","volume":"34 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139977322","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Gressa Amanda Chinelato, Gabriel Madoglio Favara, Camila Geovana Ferro, Vinicius Henrique Bello, Felipe Franco de Oliveira, Heron Delgado Kraide, David Marques de Almeida Spadotti, Nilton Tadeu Vilela Junqueira, Jorge Alberto Marques Rezende
Passionfruit severe leaf distortion virus (PSLDV) is a begomovirus transmitted by Bemisia tabaci Middle East‐Asia Minor 1 (MEAM1), associated with severe disease in passion flowers. This study aimed to evaluate the reaction of plants of different species of Passiflora to infection with PSLDV, expand the known host range of the virus and determine the minimum virus acquisition and inoculation access periods and the time of virus retention by B. tabaci MEAM1. Plants of Passiflora cincinnata, P. mucronata and P. malacophylla were not infected with PSLDV through transmission with B. tabaci MEAM1. When healthy plants of these species were fork grafted onto PSLDV‐infected plants of P. edulis, only plants of P. malacophylla remained uninfected and the virus was not detected by PCR, suggesting immunity to this begomovirus. Plants of Datura stramonium, Nicotiana benthamiana, N. clevelandii, N. tabacum ‘Xanthi’, Solanum lycopersicum (tomato cv. Compack) and several varieties of Manihot esculenta (cassava cvs IAC 118‐96, IAC 6‐01, Paranavaí, IAC 576, IAC 90 and IAC 14) were susceptible to infection with PSLDV through transmission with B. tabaci MEAM1. Adults of B. tabaci MEAM1 acquired PSLDV after 1 h of feeding on PSLDV‐infected plants of D. stramonium. They transmitted the virus to healthy plants after feeding on these plants for 1 h, although with low transmission rates. The retention time of PSLDV in the vector was 14 days.
{"title":"Passionfruit severe leaf distortion virus: Expanded host range, response of Passiflora spp. plants to infection and transmission by Bemisia tabaciMEAM1","authors":"Gressa Amanda Chinelato, Gabriel Madoglio Favara, Camila Geovana Ferro, Vinicius Henrique Bello, Felipe Franco de Oliveira, Heron Delgado Kraide, David Marques de Almeida Spadotti, Nilton Tadeu Vilela Junqueira, Jorge Alberto Marques Rezende","doi":"10.1111/ppa.13881","DOIUrl":"https://doi.org/10.1111/ppa.13881","url":null,"abstract":"Passionfruit severe leaf distortion virus (PSLDV) is a begomovirus transmitted by <jats:italic>Bemisia tabaci</jats:italic> Middle East‐Asia Minor 1 (MEAM1), associated with severe disease in passion flowers. This study aimed to evaluate the reaction of plants of different species of <jats:italic>Passiflora</jats:italic> to infection with PSLDV, expand the known host range of the virus and determine the minimum virus acquisition and inoculation access periods and the time of virus retention by <jats:italic>B. tabaci</jats:italic> MEAM1. Plants of <jats:italic>Passiflora cincinnata</jats:italic>, <jats:italic>P. mucronata</jats:italic> and <jats:italic>P. malacophylla</jats:italic> were not infected with PSLDV through transmission with <jats:italic>B. tabaci</jats:italic> MEAM1. When healthy plants of these species were fork grafted onto PSLDV‐infected plants of <jats:italic>P. edulis</jats:italic>, only plants of <jats:italic>P. malacophylla</jats:italic> remained uninfected and the virus was not detected by PCR, suggesting immunity to this begomovirus. Plants of <jats:italic>Datura stramonium</jats:italic>, <jats:italic>Nicotiana benthamiana</jats:italic>, <jats:italic>N. clevelandii</jats:italic>, <jats:italic>N. tabacum</jats:italic> ‘Xanthi’, <jats:italic>Solanum lycopersicum</jats:italic> (tomato cv. Compack) and several varieties of <jats:italic>Manihot esculenta</jats:italic> (cassava cvs IAC 118‐96, IAC 6‐01, Paranavaí, IAC 576, IAC 90 and IAC 14) were susceptible to infection with PSLDV through transmission with <jats:italic>B. tabaci</jats:italic> MEAM1. Adults of <jats:italic>B</jats:italic>. <jats:italic>tabaci</jats:italic> MEAM1 acquired PSLDV after 1 h of feeding on PSLDV‐infected plants of <jats:italic>D</jats:italic>. <jats:italic>stramonium.</jats:italic> They transmitted the virus to healthy plants after feeding on these plants for 1 h, although with low transmission rates. The retention time of PSLDV in the vector was 14 days.","PeriodicalId":20075,"journal":{"name":"Plant Pathology","volume":"21 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139950449","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Alternaria is an important toxigenic fungal genus endangering the quality of cereal grains. No data are available in the literature regarding the composition of Alternaria species in wheat from the main wheat‐cultivating regions of China. In this study, a total of 282 strains were isolated from wheat kernels collected in various provinces. Phylogenetic characterization was performed using two informative loci, ASA10 and ASA19, demonstrating that all strains belonged to A. alternata. A low molecular diversity was observed, which did not appear to be influenced by geographic origin. The secondary metabolite profile of the strains was evaluated in rice culture. Altertoxin I was synthesized at a high concentration by the majority of the strains, while the accumulation of altenuene was lower in both frequency and level than that of alternariol and its derivative. A. alternata did not cause readily observable symptoms on wheat spikes after spraying of the conidia at anthesis, but a higher quantity of altertoxin I and Alternaria DNA were detected in inoculated grains. Artificial inoculations of apple fruit showed that all examined strains were capable of causing typical rot symptoms and producing all four toxins to a certain degree. The widespread occurrence of A. alternata on wheat grains and its ability to synthesize various toxic metabolites may pose a serious hazard for both growers and consumers.
{"title":"Phylogenetic, metabolic and pathogenic characteristics of Alternaria alternata strains from wheat in China","authors":"Shouning Qiao, Hui Gu, Guizhen Ma, Jianhong Xu, Jianrong Shi, Yin‐Won Lee, Jianbo Qiu","doi":"10.1111/ppa.13880","DOIUrl":"https://doi.org/10.1111/ppa.13880","url":null,"abstract":"<jats:italic>Alternaria</jats:italic> is an important toxigenic fungal genus endangering the quality of cereal grains. No data are available in the literature regarding the composition of <jats:italic>Alternaria</jats:italic> species in wheat from the main wheat‐cultivating regions of China. In this study, a total of 282 strains were isolated from wheat kernels collected in various provinces. Phylogenetic characterization was performed using two informative loci, <jats:italic>ASA10</jats:italic> and <jats:italic>ASA19</jats:italic>, demonstrating that all strains belonged to <jats:italic>A</jats:italic>. <jats:italic>alternata</jats:italic>. A low molecular diversity was observed, which did not appear to be influenced by geographic origin. The secondary metabolite profile of the strains was evaluated in rice culture. Altertoxin I was synthesized at a high concentration by the majority of the strains, while the accumulation of altenuene was lower in both frequency and level than that of alternariol and its derivative. <jats:italic>A</jats:italic>. <jats:italic>alternata</jats:italic> did not cause readily observable symptoms on wheat spikes after spraying of the conidia at anthesis, but a higher quantity of altertoxin I and <jats:italic>Alternaria</jats:italic> DNA were detected in inoculated grains. Artificial inoculations of apple fruit showed that all examined strains were capable of causing typical rot symptoms and producing all four toxins to a certain degree. The widespread occurrence of <jats:italic>A</jats:italic>. <jats:italic>alternata</jats:italic> on wheat grains and its ability to synthesize various toxic metabolites may pose a serious hazard for both growers and consumers.","PeriodicalId":20075,"journal":{"name":"Plant Pathology","volume":"1 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139950522","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Simon R. Ellwood, Francisco J. Lopez‐Ruiz, Kar‐Chun Tan
Australia is one of the largest barley exporters in the world, with Western Australia accounting for some 40% of national production. The crop is predominantly grown in the south and south‐west of the state in winter and spring, where temperate conditions and higher rainfall levels are more suited to barley than northern and eastern regions. Between 2007 and 2013, prolonged outbreaks of barley powdery mildew (BPM) occurred. This was brought about by a combination of the extensive use of susceptible cultivars and an over‐reliance on a small number of single mode‐of‐action demethylation inhibitor fungicides, which select for mutations in the C14α‐demethylase (Cyp51A) gene. This review highlights the steps taken to reduce losses to BPM, breeding efforts to introduce resistance into cultivars and the success of pre‐breeding research to find new and durable resistance genes. We also draw comparisons with powdery mildew in Australian wheat, where similar factors are leading to substantial outbreaks.
{"title":"Barley powdery mildew control in Western Australia and beyond","authors":"Simon R. Ellwood, Francisco J. Lopez‐Ruiz, Kar‐Chun Tan","doi":"10.1111/ppa.13884","DOIUrl":"https://doi.org/10.1111/ppa.13884","url":null,"abstract":"Australia is one of the largest barley exporters in the world, with Western Australia accounting for some 40% of national production. The crop is predominantly grown in the south and south‐west of the state in winter and spring, where temperate conditions and higher rainfall levels are more suited to barley than northern and eastern regions. Between 2007 and 2013, prolonged outbreaks of barley powdery mildew (BPM) occurred. This was brought about by a combination of the extensive use of susceptible cultivars and an over‐reliance on a small number of single mode‐of‐action demethylation inhibitor fungicides, which select for mutations in the C14α‐demethylase (<jats:italic>Cyp51A</jats:italic>) gene. This review highlights the steps taken to reduce losses to BPM, breeding efforts to introduce resistance into cultivars and the success of pre‐breeding research to find new and durable resistance genes. We also draw comparisons with powdery mildew in Australian wheat, where similar factors are leading to substantial outbreaks.","PeriodicalId":20075,"journal":{"name":"Plant Pathology","volume":"255 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139950450","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Bacteriophages have emerged as effective antimicrobial agents in combating pathogenic bacteria. To successfully apply phages in real‐life scenarios, it is crucial to optimize their large‐scale production, concentration and purification processes. In this study, our objective was to optimize the phage concentration parameters with a high recovery rate within a shorter time and minimum chemical consumption. We isolated and characterized a specific Erwinia amylovora phage. Subsequently, we employed response surface methodology (RSM) combined with a three‐factor central composite design to optimize the phage recovery. The factors considered were polyethylene glycol (PEG) concentration, NaCl concentration and incubation time. The optimized values for PEG, NaCl and incubation time, which resulted in a maximum recovery rate of 85.37%, were determined as 18%, 2.38 M and 0 h, respectively. This finding indicates that the concentration step, which traditionally took up to 18 h with a recovery rate of 65%, can now be accomplished in a significantly shorter time with an improved recovery rate. Our study demonstrates the effectiveness of RSM to identify the optimum conditions for phage precipitation. This approach allows for the rapid and efficient design of precipitation protocols tailored to specific bacteriophages, resulting in shorter processing times and higher recovery rates.
{"title":"Optimization of concentration parameters for maximizing bacteriophage recovery value using response surface methodology: A case study on determining the optimal concentration parameters for Erwinia amylovoraEA1T1.B3 phage","authors":"Kubra Guven, Esra Ekiz, Eylul Evran, Emine Kubra Tayyarcan, Ismail Hakki Boyaci","doi":"10.1111/ppa.13882","DOIUrl":"https://doi.org/10.1111/ppa.13882","url":null,"abstract":"Bacteriophages have emerged as effective antimicrobial agents in combating pathogenic bacteria. To successfully apply phages in real‐life scenarios, it is crucial to optimize their large‐scale production, concentration and purification processes. In this study, our objective was to optimize the phage concentration parameters with a high recovery rate within a shorter time and minimum chemical consumption. We isolated and characterized a specific <jats:italic>Erwinia amylovora</jats:italic> phage. Subsequently, we employed response surface methodology (RSM) combined with a three‐factor central composite design to optimize the phage recovery. The factors considered were polyethylene glycol (PEG) concentration, NaCl concentration and incubation time. The optimized values for PEG, NaCl and incubation time, which resulted in a maximum recovery rate of 85.37%, were determined as 18%, 2.38 M and 0 h, respectively. This finding indicates that the concentration step, which traditionally took up to 18 h with a recovery rate of 65%, can now be accomplished in a significantly shorter time with an improved recovery rate. Our study demonstrates the effectiveness of RSM to identify the optimum conditions for phage precipitation. This approach allows for the rapid and efficient design of precipitation protocols tailored to specific bacteriophages, resulting in shorter processing times and higher recovery rates.","PeriodicalId":20075,"journal":{"name":"Plant Pathology","volume":"59 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139950413","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
William R. O. Soares, Willie A. S. Vieira, Ailton Reis, Robert N. G. Miller, Maria D. M. Santos, Érica de Castro Costa, Marcos P. S. Câmara, Adalberto C. Café-Filho
Anthracnose, caused by several Colletotrichum species, is a major restricting factor for guava production, but no comprehensive study of the causal agent has been conducted from the plant host centre of diversity. This work characterizes isolates from guava, mainly from the fruit, but also leaves and flowers, representing most Brazilian physiographies according to the partial sequences of the rDNA-ITS, ApMAT, TUB2, HIS3 and GAPDH gene regions. In addition, the pathogenicity and aggressiveness to fruits of two widely planted guava varieties (SLG and RM) are described. Guava-derived Colletotrichum isolates were found in five complexes: gloeosporioides, acutatum, boninense, gigasporum and orchidearum. The gloeosporioides complex was the most prevalent (81%), followed by the acutatum complex (14%). A total of 16 Colletotrichum species were naturally associated with guava anthracnose: C. aeschynomenes, C. asianum, C. chrysophilum, C. fructicola, C. gigasporum, C. gloeosporioides, C. karsti, C. melonis, C. musae, C. nymphaeae, C. paranaense, C. siamense, C. sojae, C. syzygicola, C. theobromicola and C. tropicale. Apart from C. nymphaeae and C. gloeosporioides, all the remaining 14 taxa are reported for the first time in P. guajava. The most aggressive species belonged to the C. gloeosporioides complex. C. siamense was the most prevalent, especially in warmer regions, followed by C. chrysophilum, mostly in temperate environments. The most aggressive species were C. siamense, C. chrysophilum, C. fructicola and C. tropicale. Fruits of the variety SLG were consistently more resistant to anthracnose than the fruits of RM.
由多种 Colletotrichum 引起的炭疽病是番石榴生产的主要限制因素，但尚未从植物寄主的多样性中心对病原进行过全面研究。这项工作根据 rDNA-ITS、ApMAT、TUB2、HIS3 和 GAPDH 基因区的部分序列，描述了从番石榴中分离出的病原菌的特征，这些病原菌主要来自果实，也有叶片和花朵，代表了巴西大部分的生理特征。此外，还介绍了两种广泛种植的番石榴品种（SLG 和 RM）的致病性和对果实的侵袭性。在五个复合体中发现了来自番石榴的 Colletotrichum 分离物：gloeosporioides、acutatum、boninense、gigasporum 和 orchidearum。最常见的是钩孢属复合体（81%），其次是尖孢属复合体（14%）。与番石榴炭疽病自然相关的 Colletotrichum 种类共有 16 种：C. aeschynomenes、C. asianum、C. chrysophilum、C. fructicola、C. gigasporum、C. gloeosporioides、C. karsti、C. melonis、C. musae、C. nymphaeae、C. paranaense、C. siamense、C. sojae、C. syzygicola、C. theobromicola 和 C. tropicale。除了 C. nymphaeae 和 C. gloeosporioides 外，其余 14 个分类群都是首次在番石榴中发现。最具攻击性的物种属于 C. gloeosporioides 复合体。C. siamense最为普遍，尤其是在温暖地区，其次是 C. chrysophilum，主要在温带环境中。最具侵袭性的种类是 C. siamense、C. chrysophilum、C. fructicola 和 C. tropicale。品种 SLG 的果实对炭疽病的抗性一直高于 RM 的果实。
{"title":"Diversity of Colletotrichum causing anthracnose on Psidium guajava in varied Brazilian physiographic regions","authors":"William R. O. Soares, Willie A. S. Vieira, Ailton Reis, Robert N. G. Miller, Maria D. M. Santos, Érica de Castro Costa, Marcos P. S. Câmara, Adalberto C. Café-Filho","doi":"10.1111/ppa.13879","DOIUrl":"https://doi.org/10.1111/ppa.13879","url":null,"abstract":"Anthracnose, caused by several <i>Colletotrichum</i> species, is a major restricting factor for guava production, but no comprehensive study of the causal agent has been conducted from the plant host centre of diversity. This work characterizes isolates from guava, mainly from the fruit, but also leaves and flowers, representing most Brazilian physiographies according to the partial sequences of the rDNA-ITS, <i>ApMAT</i>, <i>TUB2</i>, <i>HIS3</i> and <i>GAPDH</i> gene regions. In addition, the pathogenicity and aggressiveness to fruits of two widely planted guava varieties (SLG and RM) are described. Guava-derived <i>Colletotrichum</i> isolates were found in five complexes: gloeosporioides, acutatum, boninense, gigasporum and orchidearum. The gloeosporioides complex was the most prevalent (81%), followed by the acutatum complex (14%). A total of 16 <i>Colletotrichum</i> species were naturally associated with guava anthracnose: <i>C</i>. <i>aeschynomenes</i>, <i>C</i>. <i>asianum</i>, <i>C</i>. <i>chrysophilum</i>, <i>C</i>. <i>fructicola</i>, <i>C</i>. <i>gigasporum</i>, <i>C</i>. <i>gloeosporioides</i>, <i>C</i>. <i>karsti</i>, <i>C</i>. <i>melonis</i>, <i>C</i>. <i>musae</i>, <i>C</i>. <i>nymphaeae</i>, <i>C</i>. <i>paranaense</i>, <i>C</i>. <i>siamense</i>, <i>C</i>. <i>sojae</i>, <i>C</i>. <i>syzygicola</i>, <i>C</i>. <i>theobromicola</i> and <i>C</i>. <i>tropicale</i>. Apart from <i>C</i>. <i>nymphaeae</i> and <i>C</i>. <i>gloeosporioides</i>, all the remaining 14 taxa are reported for the first time in <i>P</i>. <i>guajava</i>. The most aggressive species belonged to the <i>C</i>. <i>gloeosporioides</i> complex. <i>C</i>. <i>siamense</i> was the most prevalent, especially in warmer regions, followed by <i>C</i>. <i>chrysophilum</i>, mostly in temperate environments. The most aggressive species were <i>C</i>. <i>siamense</i>, <i>C</i>. <i>chrysophilum</i>, <i>C</i>. <i>fructicola</i> and <i>C</i>. <i>tropicale</i>. Fruits of the variety SLG were consistently more resistant to anthracnose than the fruits of RM.","PeriodicalId":20075,"journal":{"name":"Plant Pathology","volume":"34 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139917778","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：