Recognition of an Avr3a Homologue Plays a Major Role in Mediating Nonhost Resistance to Phytophthora capsici in Nicotiana Species

Julio C. Vega-Arreguín; Abubakar Jalloh; Jorunn I. Bos; Peter Moffett

doi:10.1094/mpmi-01-14-0014-r

Recognition of an Avr3a Homologue Plays a Major Role in Mediating Nonhost Resistance to Phytophthora capsici in Nicotiana Species

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi-01-14-0014-r ◽

2014 ◽

Vol 27 (8) ◽

pp. 770-780 ◽

Cited By ~ 36

Author(s):

Julio C. Vega-Arreguín ◽

Abubakar Jalloh ◽

Jorunn I. Bos ◽

Peter Moffett

Keyword(s):

Molecular Mechanisms ◽

Phytophthora Capsici ◽

Nonhost Resistance ◽

Effector Protein ◽

R Gene ◽

R Genes ◽

Phytophthora Blight ◽

Nicotiana Species ◽

Rxlr Effector ◽

Blight Disease

Nonhost resistance is a commonly occurring phenomenon wherein all accessions or cultivars of a plant species are resistant to all strains of a pathogen species and is likely the manifestation of multiple molecular mechanisms. Phytophthora capsici is a soil-borne oomycete that causes Phytophthora blight disease in many solanaceous and cucurbitaceous plants worldwide. Interest in P. capsici has increased considerably with the sequencing of its genome and its increasing occurrence in multiple crops. However, molecular interactions between P. capsici and both its hosts and its nonhosts are poorly defined. We show here that tobacco (Nicotiana tabacum) acts like a nonhost for P. capsici and responds to P. capsici infection with a hypersensitive response (HR). Furthermore, we have found that a P. capsici Avr3a-like gene (PcAvr3a1) encoding a putative RXLR effector protein produces a HR upon transient expression in tobacco and several other Nicotiana species. This HR response correlated with resistance in 19 of 23 Nicotiana species and accessions tested, and knock-down of PcAvr3a1 expression by host-induced gene silencing allowed infection of resistant tobacco. Our results suggest that many Nicotiana species have the capacity to recognize PcAvr3a1 via the products of endogenous disease resistance (R) genes and that this R gene–mediated response is a major component of nonhost resistance to P. capsici.

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Peningkatan Pertumbuhan Tanaman Cabai dan Pengendalian Busuk Phytophthora melalui Biopriming Benih dengan Rizobakteri Asal Pertanaman Cabai Jawa Timur

Jurnal Hortikultura Indonesia ◽

10.29244/jhi.8.3.171-182 ◽

2017 ◽

Vol 8 (3) ◽

pp. 171 ◽

Cited By ~ 2

Author(s):

Aulia Zakia ◽

Satriyas Ilyas ◽

Candra Budiman ◽

Syamsuddin , ◽

Dyah Manohara

Keyword(s):

Plant Growth ◽

Seed Treatment ◽

Block Design ◽

Phytophthora Capsici ◽

Positive Control ◽

Negative Control ◽

Phytophthora Blight ◽

Blight Disease ◽

And Control ◽

East West

ABSTRACT The objectives of this study was to evaluate biopriming of chili seed with rhizobacteria to improve plant growth and control Phytophthora blight disease in a greenhouse. This experiment used three isolates of rhizobacteria, i.e. E1, E3C2 and F2B1, and isolate Phytophthora capsici (Cb6) isolated from the production center of chili in East Jawa. Laris variety from PT. East West was used in this experiment. This experiment used randomized block design with one factor, i.e. 11 levels of seed treatment (E1 rhizobacteria, E3C2 rhizobacteria, F2B1 rhizobacteria, E1+E3C2 rhizobacteria, E1+F2B1 rhizobacteria, E1+E3C2+F2B1 rhizobacteria, seed soaking in water, without soaking, metalaxyl, positive control and negative control). The result showed that seed treatment with combination of E1+F2B1 isolates when grown in nursery, significantly increased the height and number of leaves in chilli. Besides, seed treatment with F2B1 isolate and combination of E1+F2B1 isolates after transplanting were capable to improve plant growth and control Phytophthora blight disease in greenhouse.Keywords: greenhouse, isolate rhizobacteria, Phytophthora capsici ABSTRAK Tujuan penelitian ini ialah mengevaluasi perlakuan biopriming benih cabai dengan rizobakteri dalam meningkatkan pertumbuhan bibit dan mengendalikan kejadian busuk Phytophthora di rumah kaca. Perlakuan biopriming benih dengan rizobakteri menggunakan tiga isolat rizobakteri E1, E3C2 dan F2B1 dan isolat Phytophthora capsici Cb6 hasil eksplorasi pertanaman cabai Jawa Timur. Benih yang digunakan dalam percobaan merupakan benih varietas Laris produksi PT. East West. Percobaan menggunakan rancangan acak kelompok satu faktor, masing-masing perlakuan diulang empat kali, dengan 11 taraf perlakuan, antara lain R0+ (kontrol positif, benih direndam dalam PDB tanpa perlakuan rizobakteri dengan inokulasi P. capsici), R0- (kontrol negatif, benih direndam dalam PDB tanpa perlakuan rizobakteri dan tanpa inokulasi P. capsici), R1 (perlakuan benih dengan isolat E1), R2 (isolat E3C2), R3 (isolat F2B1), R4 (kombinasi isolat E1+E3C2), R5 (kombinasi isolat E1+F2B1), R6 (kombinasi isolat E1+E3C2+F2B1), R0RA (benih direndam dalam air 24 jam), R0TR (benih tanpa rendam), R0M (benih direndam dalam metalaksil). Tanah inokulum P. capsici diberikan 28 hari setelah pindah-tanam di sekitar pangkal batang tanaman cabai di bawah permukaan tanah. Hasil percobaan menunjukkan, perlakuan dengan kombinasi isolat E1+F2B1 saat persemaian di rumah kaca nyata meningkatkan tinggi dan jumlah daun tanaman cabai. Perlakuan benih dengan isolat F2B1 maupun kombinasi isolat E1+F2B1 setelah pindah-tanam di rumah kaca memiliki kemampuan meningkatkan pertumbuhan tanaman serta mengendalikan penyakit busuk Phytophthora. Kata kunci: isolat rizobakteri, Phytophthora capsici, rumah kaca

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Screening of phytochemicals from selected plants with antifungal properties against RXLR effector protein Avr3a11in Phytophthora capsici

Canadian Journal of Biotechnology ◽

10.24870/cjb.2017-a21 ◽

2017 ◽

Vol 1 (Special Issue) ◽

pp. 34-34

Author(s):

Rani J.R. ◽

Aswathy T.R. ◽

Maala S. Kumar ◽

Achuthsankar S. Nair ◽

Soniya E.V.

Keyword(s):

Phytophthora Capsici ◽

Effector Protein ◽

Antifungal Properties ◽

Rxlr Effector

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EXPLORATION AND SELECTION OF RHIZOBACTERIA THAT INHIBIT PHYTOPHTHORA CAPSICI IN VITRO

JURNAL HAMA DAN PENYAKIT TUMBUHAN TROPIKA ◽

10.23960/j.hptt.11883-94 ◽

2018 ◽

Vol 18 (1) ◽

pp. 83

Author(s):

Aulia Zakia ◽

Satriyas Ilyas ◽

Candra Budiman ◽

Syamsuddin . ◽

Dyah Manohara

Keyword(s):

Phytophthora Capsici ◽

Culture Method ◽

Healthy Plant ◽

Dual Culture ◽

Phytophthora Blight ◽

Heated Sample ◽

Resistant Varieties ◽

Blight Disease ◽

Selection Of

Exploration and Selection of Rhizobacteria that Inhibit Phytophthora capsici in vitro. Phytophthora capsici, a seed borne and the soil borne fungal pathogen is the cause of phytophthora blight on chili. The disease is difficult to control because of the resistant varieties unavailability in Indonesia. The aimed was to obtain isolates of rhizobacteria which has the ability to inhibit P. capsici in vitro. Rhizobacteria exploration was conducted in the chili production center in East Java (Malang, Batu, and Kediri) and West Java (Bogor). In one location, chili plant that had symptoms of phytophthora blight disease and a healthy plant next to it were chosen as samples to isolate P. capsici and the rhizobacteria. The rhizobacteria were isolated on NA, TSA, and TSAP (TSA with heated sample). Samples of diseased plants were used in isolation of P. capsici on V8 agar. The inhibition and compatibility of the rhizobacteria to inhibit P. capsici in vitro were tested by dual culture method. In this experiment, it was obtained 252 isolates of rhizobacteria and one isolate of P. capsici. Isolates of rhizobacteria with high to medium inhibition were E1, E3C2, and F2B1 respectively. All three isolates were then combined and tested against P. capsici in vitro. The highest inhibition was indicated by four isolate and combination of isolates, which were E1 isolate (58%), the combination of E1 + E3C2 isolates (58%), E1 + F2B1 (60%) and E1 + E3C2 + F2B1 (58 %).

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Perlakuan Benih Cabai (Capsicum annuum L.) dengan Rizobakteri secara Tunggal atau Kombinasi dapat Mengendalikan Phytophthora capsici dan Meningkatkan Pertumbuhan Tanaman

Jurnal Hortikultura Indonesia ◽

10.29244/jhi.6.1.1-10 ◽

2015 ◽

Vol 6 (1) ◽

pp. 1 ◽

Cited By ~ 1

Author(s):

Farih Najah Rosadiah ◽

Satriyas Ilyas ◽

Dyah Manohara

Keyword(s):

Seed Treatment ◽

Phytophthora Capsici ◽

Positive Control ◽

Negative Control ◽

Hot Pepper ◽

Phytophthora Blight ◽

Randomized Design ◽

Phytophthora Rot ◽

Blight Disease

ABSTRACTSeed treatment of hot pepper using rhizobacteria is an alternative to fungicide use in controlling phytophthora rot disease. The objectives of this research were to evaluate: (1) the effectiveness of rhizobacteria isolates in inhibiting Phytophthora capsici growth and (2) the effect of seed treatment using rhizobacteria on plant growth, and incidence of phytophthora blight disease. This research consisted of two experiments, all experiments were arranged in completely randomized design using one factor. The first experiment (in vitro) consisted of nine levels i.e. sevencombination isolates of rhizobacteria, metalaxyl and control. The second experiment (in the green house) consisted of six levels of seed treatments i.e. ST116B rhizobacteria, CM8 rhizobacteria, ST116B + CM8 rhizobacteria, metalaxyl, positive control and negative control. Results of in vitro experiment showed that all rhizobacteria, single or combinations, were able to inhibit P. capsicigrowth. The highest inhibition were shown by CM8, ST116B + CM8, and ST116B consecutively.Seed treatments of hot pepper using ST116B, CM8, and ST116B + CM8 rhizobacteria increased the number of leaves 6 weeks after transplanting and reduced the incidence of phytophthora blight disease. There were no significant differences whether the rhizobacteria was applied singly or in combination of the two. Rhizobacteria ST116B was suggested for pepper seed treatment before planting.Keywords: metalaxyl, phytophthora blight disease, rhizobacteria ABSTRAKPerlakuan benih cabai menggunakan rizobakteri merupakan alternatif pengganti fungisida dalam mengendalikan penyakit busuk phytophthora, yang disebabkan oleh cendawan patogen Phytophthora capsici. Penelitian ini bertujuan (1) mengevaluasi keefektifan kombinasi isolat rizobakteri dalam menghambat pertumbuhan P. capsici, dan (2) mengetahui pengaruh perlakuan benih dengan rizobakteri dalam meningkatkan vigor benih dan pertumbuhan tanaman, serta dalam mengurangi kejadian penyakit busuk phytophthora. Penelitian ini terdiri atas dua tahap percobaan, menggunakan rancangan acak lengkap satu faktor. Percobaan pertama (in vitro) terdiri atas sembilan taraf yaitu tujuh kombinasi isolat rizobakteri, metalaksil, dan tanpa perlakuan (kontrol). Percobaan kedua (di rumah kaca) terdiri atas enam taraf perlakuan benih yaitu rizobakteri ST116B, CM8, ST116B + CM8, metalaksil, kontrol positif, dan kontrol negatif. Hasil percobaan in vitro, semua perlakuan rizobakteri baik tunggal maupun yang dikombinasikan mampu menghambat pertumbuhan patogen P. capsici. Persentase daya hambat tertinggi berturut-turut ditunjukkan oleh isolat rizobakteri CM8, kombinasi isolat rizobakteri ST116B + CM8, dan isolat rizobakteri ST116B. Perlakuan benih dengan rizobakteri ST116B, CM8, dan ST116B + CM8 tidak dapat meningkatkan vigor benih, namun secara nyata meningkatkan pertambahan jumlah daun pada minggu ke enam setelah pindah tanam, dan menurunkan kejadian penyakit busuk phytophthora. Tidak terdapat perbedaan nyata pengaruh rizobakteri yang diaplikasikan secara tunggal maupun kombinasi dua isolat. Rizobakteri ST116B disarankan untuk digunakan dalam perlakuan benih cabai sebelum tanam.Kata kunci: metalaksil, penyakit busuk phytophthora, rizobakteri

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Isolation and Characterization Of Rice R Genes: Evidence for Distinct Evolutionary Paths in Rice and Maize

Genetics ◽

10.1093/genetics/142.3.1021 ◽

1996 ◽

Vol 142 (3) ◽

pp. 1021-1031 ◽

Cited By ~ 3

Author(s):

Jianping Hu ◽

Beth Anderson ◽

Susan R Wessler

Keyword(s):

Gene Family ◽

Gene Families ◽

Chromosome 1 ◽

R Gene ◽

R Genes ◽

Helix Loop Helix ◽

Isolation And Characterization ◽

Undetermined Function ◽

Evolutionary Paths

Abstract R and B genes and their homologues encode basic helix-loop-helix (bHLH) transcriptional activators that regulate the anthocyanin biosynthetic pathway in flowering plants. In maize, R/B genes comprise a very small gene family whose organization reflects the unique evolutionary history and genome architecture of maize. To know whether the organization of the R gene family could provide information about the origins of the distantly related grass rice, we characterized members of the R gene family from rice Oryza sativa. Despite being a true diploid, O. sativa has at least two R genes. An active homologue (Ra) with extensive homology with other R genes is located at a position on chromosome 4 previously shown to be in synteny with regions of maize chromosomes 2 and 10 that contain the B and R loci, respectively. A second rice R gene (Rb) of undetermined function was identified on chromosome 1 and found to be present only in rice species with AA genomes. All non-AA species have but one R gene that is Ra-like. These data suggest that the common ancestor shared by maize and rice had a single R gene and that the small R gene families of grasses have arisen recently and independently.

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Recent Findings Unravel Genes and Genetic Factors Underlying Leptosphaeria maculans Resistance in Brassica napus and Its Relatives

International Journal of Molecular Sciences ◽

10.3390/ijms22010313 ◽

2020 ◽

Vol 22 (1) ◽

pp. 313

Author(s):

Aldrin Y. Cantila ◽

Nur Shuhadah Mohd Saad ◽

Junrey C. Amas ◽

David Edwards ◽

Jacqueline Batley

Keyword(s):

Brassica Napus ◽

Genetic Factors ◽

Quantitative Resistance ◽

Genetic Resistance ◽

Leptosphaeria Maculans ◽

Gene Interaction ◽

R Gene ◽

R Genes ◽

Blackleg Resistance ◽

Avr Gene

Among the Brassica oilseeds, canola (Brassica napus) is the most economically significant globally. However, its production can be limited by blackleg disease, caused by the fungal pathogen Lepstosphaeria maculans. The deployment of resistance genes has been implemented as one of the key strategies to manage the disease. Genetic resistance against blackleg comes in two forms: qualitative resistance, controlled by a single, major resistance gene (R gene), and quantitative resistance (QR), controlled by numerous, small effect loci. R-gene-mediated blackleg resistance has been extensively studied, wherein several genomic regions harbouring R genes against L. maculans have been identified and three of these genes were cloned. These studies advance our understanding of the mechanism of R gene and pathogen avirulence (Avr) gene interaction. Notably, these studies revealed a more complex interaction than originally thought. Advances in genomics help unravel these complexities, providing insights into the genes and genetic factors towards improving blackleg resistance. Here, we aim to discuss the existing R-gene-mediated resistance, make a summary of candidate R genes against the disease, and emphasise the role of players involved in the pathogenicity and resistance. The comprehensive result will allow breeders to improve resistance to L. maculans, thereby increasing yield.

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Xa7, a new executor R gene that confers durable and broad-spectrum resistance to bacterial blight disease in rice

Plant Communications ◽

10.1016/j.xplc.2021.100143 ◽

2021 ◽

pp. 100143

Author(s):

Xifeng Chen ◽

Pengcheng Liu ◽

Le Mei ◽

Xiaoling He ◽

Long Chen ◽

...

Keyword(s):

Broad Spectrum ◽

Bacterial Blight ◽

R Gene ◽

Broad Spectrum Resistance ◽

Bacterial Blight Disease ◽

Blight Disease

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Fitness of Isolates of Phytophthora capsici Resistant to Mefenoxam from Squash and Pepper Fields in North Carolina

Plant Disease ◽

10.1094/pdis-92-10-1439 ◽

2008 ◽

Vol 92 (10) ◽

pp. 1439-1443 ◽

Cited By ~ 24

Author(s):

Adalberto C. Café-Filho ◽

Jean Beagle Ristaino

Keyword(s):

North Carolina ◽

Phytophthora Capsici ◽

Colony Growth ◽

Relative Fitness ◽

In Planta ◽

Phytophthora Blight ◽

In Vivo Experiments ◽

First Time

Despite the wide adoption of mefenoxam (Ridomil Gold EC) for vegetables in North Carolina, the incidence of Phytophthora blight on pepper (Capsicum annuum) and squash (Cucurbita pepo) is high. Seventy-five isolates of Phytophthora capsici were collected in five pepper and one squash field in order to assess mefenoxam sensitivity. The relative fitness of resistant and sensitive isolates was contrasted in vitro by their respective rates of colony growth and their ability to produce sporangia in unamended V8 juice agar medium. In in vivo experiments, the aggressiveness of isolates on pepper was evaluated. The frequency of resistant isolates in North Carolina populations was 63%, considerably higher than resistance levels in areas where mefenoxam is not widely adopted. Resistant isolates grew on amended media at rates >80 to 90% and >100% of the nonamended control at 100 μg ml-1 and 5 μg ml-1, respectively. Sensitive isolates did not growth at 5 or 100 μg ml-1. All isolates from three fields, including two pepper and a squash field, were resistant to mefenoxam. Populations from other fields were composed of either mixes of sensitive and resistant isolates or only sensitive isolates. Response to mefenoxam remained stable during the course of in vitro and in planta experiments. Occurrence of a mefenoxam-resistant population of P. capsici on squash is reported here for the first time in North Carolina. When measured by rate of colony growth, sporulation in vitro, or aggressiveness in planta, fitness of resistant isolates was not reduced. Mefenoxam-resistant isolates from squash were as aggressive on pepper as sensitive or resistant pepper isolates. These results suggest that mefenoxam-resistant populations of P. capsici are as virulent and fit as sensitive populations.

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Multiyear Evaluation of the Durability of the Resistance Conferred by Ma and RMia Genes to Meloidogyne incognita in Prunus Under Controlled Conditions

Phytopathology ◽

10.1094/phyto-09-12-0228-r ◽

2013 ◽

Vol 103 (8) ◽

pp. 833-840 ◽

Cited By ~ 5

Author(s):

Samira Khallouk ◽

Roger Voisin ◽

Ulysse Portier ◽

Joël Polidori ◽

Cyril Van Ghelder ◽

...

Keyword(s):

Meloidogyne Incognita ◽

Economic Losses ◽

R Gene ◽

R Genes ◽

Tomato Plants ◽

Controlled Conditions ◽

Meloidogyne Spp ◽

Resistance Breakdown ◽

Susceptible Tomato ◽

Prunus Spp

Root-knot nematodes (RKNs) (Meloidogyne spp.) are highly polyphagous pests that parasitize Prunus crops in Mediterranean climates. Breeding for RKN-resistant Prunus cultivars, as an alternative to the now-banned use of nematicides, is a real challenge, because the perennial nature of these trees increases the risk of resistance breakdown. The Ma plum resistance (R) gene, with a complete spectrum, and the RMia peach R gene, with a more restricted spectrum, both provide total control of Meloidogyne incognita, the model parthenogenetic species of the genus and the most important RKN in terms of economic losses. We investigated the durability of the resistance to this nematode conferred by these genes, comparing the results obtained with those for the tomato Mi-1 reference gene. In multiyear experiments, we applied a high and continuous nematode inoculum pressure by cultivating nematode-infested susceptible tomato plants with either Prunus accessions carrying Ma or RMia R genes, or with resistant tomato plants carrying the Mi-1 gene. Suitable conditions for Prunus development were achieved by carrying out the studies in a glasshouse, in controlled conditions allowing a short winter leaf fall and dormancy. We first assessed the plum accession ‘P.2175’, which is heterozygous for the Ma gene, in two successive 2-year evaluations, for resistance to two M. incognita isolates. Whatever the isolate used, no nematodes reproducing on P.2175 were detected, whereas galls and nematodes reproducing on tomato plants carrying Mi-1 were observed. In a second experiment with the most aggressive isolate, interspecific full-sib material (P.2175 × [‘Garfi’ almond × ‘Nemared’ peach]), carrying either Ma or RMia (from Nemared) or both (in the heterozygous state) or neither of these genes, was evaluated for 4 years. No virulent nematodes developed on Prunus spp. carrying R genes, whereas galling and virulent individuals were observed on Mi-1-resistant tomato plants. Thus, the resistance to M. incognita conferred by Ma in Prunus material in both a pure-plum and an interspecific genetic background, or by RMia in an interspecific background, appears to be durable, highlighting the value of these two genes for the creation of Prunus rootstock material.

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Identification of the Pathogen Causing Stem Blight Disease on Chili in Sindangjaya Village, Cipanas, Cianjur, West Java Based on Morphological and Molecular Analyses

Jurnal AgroBiogen ◽

10.21082/jbio.v17n1.2021.p35-44 ◽

2021 ◽

Vol 17 (1) ◽

pp. 35

Author(s):

Wartono Wartono

Keyword(s):

Molecular Identification ◽

Phytophthora Capsici ◽

Economic Value ◽

Morphological Characters ◽

Stem Rot ◽

West Java ◽

Molecular Analyses ◽

Molecular Approaches ◽

Rot Disease ◽

Blight Disease

Chili (Capsicum annuum L.) is a vegetable commodity with high economic value which is widely cultivated by farmers in Indonesia. One of the obstacles faced in chili cultivation is stem rot disease. This study aimed to identify the pathogens that caused stem rot in chili plants obtained from one location in Sindangjaya Village, Cipanas District, Cianjur Regency, West Java Province based on morphological and molecular analyses. Pathogen identification was performed with morphological and molecular approaches. The morphological characters observed included colony shape, sporangium diameter, and mating type. The pathogenicity of the isolates was assayed by inoculating chili stems aged 40 days. Molecular identification was carried out using two pairs of primers for ITS regions and TEF-1 gene. Based on the results of morphological and molecular identification, as well as pathogenicity tests, it was confirmed that Phytophthora capsici pathogen was the causal agent of stem rot in chili plants collected from Sindangjaya Village. Further study is needed to determine the spread of the disease, damage, and yield loss caused by stem rot disease, as well as how to prevent and control the disease.

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