scholarly journals Functional Contribution of Chorismate Synthase, Anthranilate Synthase, and Chorismate Mutase to Penetration Resistance in Barley–Powdery Mildew Interactions

2009 ◽  
Vol 22 (3) ◽  
pp. 311-320 ◽  
Author(s):  
Pingsha Hu ◽  
Yan Meng ◽  
Roger P. Wise
Keyword(s):  
Powdery Mildew ◽  
Gene Silencing ◽  
Penetration Resistance ◽  
Negative Regulator ◽  
Chorismate Mutase ◽  
Anthranilate Synthase ◽  
Resistance Locus ◽  
Chorismate Synthase ◽  
Mildew Resistance ◽  
Barley Powdery Mildew

Plant processes resulting from primary or secondary metabolism have been hypothesized to contribute to defense against microbial attack. Barley chorismate synthase (HvCS), anthranilate synthase α subunit 2 (HvASa2), and chorismate mutase 1 (HvCM1) occupy pivotal branch points downstream of the shikimate pathway leading to the synthesis of aromatic amino acids. Here, we provide functional evidence that these genes contribute to penetration resistance to Blumeria graminis f. sp. hordei, the causal agent of powdery mildew disease. Single-cell transient-induced gene silencing of HvCS and HvCM1 in mildew resistance locus a (Mla) compromised cells resulted in increased susceptibility. Correspondingly, overexpression of HvCS, HvASa2, and HvCM1 in lines carrying mildew resistance locus o (Mlo), a negative regulator of penetration resistance, significantly decreased susceptibility. Barley stripe mosaic virus–induced gene silencing of HvCS, HvASa2, and HvCM1 significantly increased B. graminis f. sp. hordei penetration into epidermal cells, followed by formation of haustoria and secondary hyphae. However, sporulation of B. graminis f. sp. hordei was not detected on the silenced host plants up to 3 weeks after inoculation. Taken together, these results establish a previously unrecognized role for the influence of HvCS, HvASa2, and HvCM1 on penetration resistance and on the rate of B. graminis f. sp. hordei development in Mla-mediated, barley–powdery mildew interactions.

Haplotype characterization and markers at the barley Mlo powdery mildew resistance locus as tools for marker-assisted selection

Genome ◽  
2006 ◽  
Vol 49 (8) ◽  
pp. 864-872 ◽  
Author(s):  
G Tacconi ◽  
V Baldassarre ◽  
N C Collins ◽  
D Bulgarelli ◽  
A M Stanca ◽  
...  
Keyword(s):  
Powdery Mildew ◽  
Marker Assisted Selection ◽  
Powdery Mildew Resistance ◽  
Resistance Locus ◽  
Nucleotide Polymorphisms ◽  
Single Nucleotide ◽  
Mildew Resistance ◽  
Barley Cultivars ◽  
Barley Powdery Mildew ◽  
Almost All

Recessive mlo alleles of the barley Mlo gene confer resistance to almost all known isolates of the powdery mildew fungal pathogen targeting barley (Hordeum vulgare). To characterize haplotypes present in the Mlo chromosomal region of cultivated Mlo and mlo barley genotypes, weconducted a polymorphism search in 3 predicted low-copy sequence regions adjacent to the Mlo gene by examining a sample of 4 Mlo and 3 mlo cultivars. Eight single-nucleotide polymorphisms (SNPs) and 1 insertion–deletion (indel) were detected, and easy to use PCR-based markers were developed for typing the SNPs. The PCR markers were used to characterize a collection of 46 Mlo and 25 mlo barley cultivars, identifying 3 distinct mlo-11 haplotypes, 1 mlo-9 haplotype, and 4 Mlo haplotypes. We summarized the haplotype and marker information obtained here and in a previous study to help breeders identify strategies for mlo marker-assisted selection. The ability of the markers to identify mlo-resistant genotypes in segregating populations was demonstrated using 2 resistance-characterized F2 populations derived by 3-way crosses.Key words: barley, powdery mildew resistance, mlo, SNPs, marker-assisted selection.

Identification and mapping of PmSE5785, a new recessive powdery mildew resistance locus, in synthetic hexaploid wheat

Euphytica ◽  
2015 ◽  
Vol 207 (3) ◽  
pp. 619-626 ◽  
Author(s):  
Yajuan Wang ◽  
Changyou Wang ◽  
Wei Quan ◽  
Xiujuan Jia ◽  
Ying Fu ◽  
...  
Keyword(s):  
Powdery Mildew ◽  
Hexaploid Wheat ◽  
Powdery Mildew Resistance ◽  
Synthetic Hexaploid Wheat ◽  
Resistance Locus ◽  
Mildew Resistance ◽  
Synthetic Hexaploid

scholarly journals Selections from barley landrace collected in Libya as new sources of effective resistance to powdery mildew (Blumeria graminis f.sp. hordei)

2011 ◽  
Vol 48 (No. 5) ◽  
pp. 217-223 ◽  
Author(s):  
J.H. Czembor ◽  
H.J. Czembor
Keyword(s):  
Powdery Mildew ◽  
Powdery Mildew Resistance ◽  
Agricultural Research ◽  
Genetic Resistance ◽  
Recessive Gene ◽  
Blumeria Graminis ◽  
Hordeum Vulgare L ◽  
Mildew Resistance ◽  
Barley Landrace ◽  
Barley Powdery Mildew

Powdery mildew on barley (Hordeum vulgare L.) caused by the pathogen Blumeria graminis f.sp. hordei occurs worldwide and can result in severe yield loss. Because agronomical methods to control the disease are not completely effective, cultivars with genetic resistance are needed. Therefore, there is a need to describe new sources of genes that confer resistance to barley powdery mildew. This study was conducted to determine the genetic basis of resistance to powdery mildew in three selections 995-1-1, 995-1-2, 995-1-3 from barley landrace 995 (ICB 112840) collected in Al Aziziyah district, Tripolitania, Libya. Landrace originated from InternationalCenter for Agricultural Research in the Dry Areas – ICARDA, Aleppo, Syria. To determine the number of genes, the types of genes action and the gene loci in tested lines two types of crosses were made: (1) the lines were crossed to the susceptible cultivar Pallas, (2) the lines were crossed with Pallas isoline P22 carrying gene mlo5. The parents and progeny F2 were evaluated with isolate R303.1 for the powdery mildew resistance. Based on segregation ratios we found that resistance in these three selections was determined by a single recessive gene allelic to the Mlo locus occurring in Pallas isoline P22. In addition tested lines showed resistance reaction type 0(4) characteristic only for genes mlo. The value of new identified sources of highly effective powdery mildew resistance to breeding programs and barley production is discussed.

scholarly journals Virus-Induced Gene Silencing-Based Functional Characterization of Genes Associated with Powdery Mildew Resistance in Barley

2005 ◽  
Vol 138 (4) ◽  
pp. 2155-2164 ◽  
Author(s):  
Ingo Hein ◽  
Maria Barciszewska-Pacak ◽  
Katarina Hrubikova ◽  
Sandie Williamson ◽  
Malene Dinesen ◽  
...  
Keyword(s):  
Powdery Mildew ◽  
Gene Silencing ◽  
Powdery Mildew Resistance ◽  
Functional Characterization ◽  
Virus Induced Gene Silencing ◽  
Mildew Resistance

scholarly journals RMo1 Confers Blast Resistance in Barley and Is Located within the Complex of Resistance Genes Containing Mla, a Powdery Mildew Resistance Gene

2006 ◽  
Vol 19 (9) ◽  
pp. 1034-1041 ◽  
Author(s):  
Tsuyoshi Inukai ◽  
M. Isabel Vales ◽  
Kiyosumi Hori ◽  
Kazuhiro Sato ◽  
Patrick M. Hayes
Keyword(s):  
Powdery Mildew ◽  
Linkage Map ◽  
Resistance Gene ◽  
Resistance Genes ◽  
Rice Blast ◽  
Powdery Mildew Resistance ◽  
Blast Disease ◽  
Grass Species ◽  
Resistance Locus ◽  
Mildew Resistance

Isolates of Magnaporthe oryzae (the causal agent of rice blast disease) can infect a range of grass species, including barley. We report that barley Hordeum vulgare cv. Baronesse and an experimental line, BCD47, show a range of resistance reactions to infection with two rice blast isolates. The complete resistance of Baronesse to the isolate Ken 54–20 is controlled by a single dominant gene, designated RMo1. RMo1 mapped to the same linkage map position on chromosome 1H as the powdery mildew resistance locus Mla and an expressed sequence tag (k04320) that corresponds to the barley gene 711N16.16. A resistance quantitative trait locus (QTL), at which Baronesse contributed the resistance allele, to the isolate Ken 53–33 also mapped at the same position as RMo1. Synteny analysis revealed that a corresponding region on rice chromosome 5 includes the bacterial blight resistance gene xa5. These results indicate that a defined region on the short arm of barley chromosome 1H, including RMo1 and Mla, harbors genes conferring qualitative and quantitative resistance to multiple pathogens. The partial resistance of BCD47 to Ken53–33 is determined by alleles at three QTL, two of which coincide with the linkage map positions of the mildew resistance genes mlo and Mlf.

scholarly journals Cultivar-Based Introgression Mapping Reveals Wild Species-Derived Pm-0, the Major Powdery Mildew Resistance Locus in Squash

PLoS ONE ◽  
2016 ◽  
Vol 11 (12) ◽  
pp. e0167715 ◽  
Author(s):  
William L. Holdsworth ◽  
Kyle E. LaPlant ◽  
Duane C. Bell ◽  
Molly M. Jahn ◽  
Michael Mazourek
Keyword(s):  
Powdery Mildew ◽  
Wild Species ◽  
Powdery Mildew Resistance ◽  
Resistance Locus ◽  
Mildew Resistance

scholarly journals Host-Induced Gene Silencing in Barley Powdery Mildew Reveals a Class of Ribonuclease-Like Effectors

2013 ◽  
Vol 26 (6) ◽  
pp. 633-642 ◽  
Author(s):  
Clara Pliego ◽  
Daniela Nowara ◽  
Giulia Bonciani ◽  
Dana M. Gheorghe ◽  
Ruo Xu ◽  
...  
Keyword(s):  
Powdery Mildew ◽  
Gene Silencing ◽  
Transcript Abundance ◽  
Powdery Mildew Fungus ◽  
Host Cell Death ◽  
Barley Powdery Mildew ◽  
Biotrophic Pathogens ◽  
Powdery Mildew Fungi ◽  
Bona Fide ◽  
Do So

Obligate biotrophic pathogens of plants must circumvent or counteract defenses to guarantee accommodation inside the host. To do so, they secrete a variety of effectors that regulate host immunity and facilitate the establishment of pathogen feeding structures called haustoria. The barley powdery mildew fungus Blumeria graminis f. sp. hordei produces a large number of proteins predicted to be secreted from haustoria. Fifty of these Blumeria effector candidates (BEC) were screened by host-induced gene silencing (HIGS), and eight were identified that contribute to infection. One shows similarity to β-1,3 glucosyltransferases, one to metallo-proteases, and two to microbial secreted ribonucleases; the remainder have no similarity to proteins of known function. Transcript abundance of all eight BEC increases dramatically in the early stages of infection and establishment of haustoria, consistent with a role in that process. Complementation analysis using silencing-insensitive synthetic cDNAs demonstrated that the ribonuclease-like BEC 1011 and 1054 are bona fide effectors that function within the plant cell. BEC1011 specifically interferes with pathogen-induced host cell death. Both are part of a gene superfamily unique to the powdery mildew fungi. Structural modeling was consistent, with BEC1054 adopting a ribonuclease-like fold, a scaffold not previously associated with effector function.

scholarly journals Identification and Characterization of a Potential Candidate Mlo Gene Conferring Susceptibility to Powdery Mildew in Rubber Tree

2019 ◽  
Vol 109 (7) ◽  
pp. 1236-1245 ◽  
Author(s):  
Bi Qin ◽  
Meng Wang ◽  
Hai-xia He ◽  
Hua-xing Xiao ◽  
Yu Zhang ◽  
...  
Keyword(s):  
Powdery Mildew ◽  
Reverse Genetics ◽  
Gene Evolution ◽  
Durable Resistance ◽  
Rubber Tree ◽  
Susceptibility Gene ◽  
Endoplasmic Reticulum Membrane ◽  
Resistance Locus ◽  
Potential Candidate ◽  
Mildew Resistance

Mildew resistance locus O (Mlo) gene was first found in barley as a powdery mildew susceptibility gene, and recessive mlo alleles confer durable resistance to barley powdery mildew. To identify candidate Mlo susceptibility genes in rubber tree, HbMlo12 was cloned from rubber tree clone CATAS7-33-97, which is susceptible to powdery mildew. Protein architecture analysis showed that HbMlo12 was a typical Mlo protein with seven transmembrane domains. Protein blast search in the Arabidopsis thaliana proteome database showed that HbMlo12 shared the highest similarity with AtMlo12, with 63% sequence identity. Furthermore, HbMlo12 together with the dicot powdery mildew susceptible Mlo proteins (including AtMlo2, AtMlo6, AtMlo12, tomato SlMlo1, pepper CaMlo2, pea PsMlo1, etc.) were grouped into clade V. Subcellular localization analysis in tobacco epidermal cells revealed that HbMlo12 was localized to the endoplasmic reticulum membrane. HbMlo12 was preferentially expressed in the flower and leaf of rubber tree. Moreover, its expression was significantly upregulated in response to powdery mildew inoculation. Application of exogenous ethephon caused a distinct increase in HbMlo12 expression. Additionally, HbMlo12 transcript was quickly induced by spraying salicylic acid and gibberellic acid and reached the maximum at 0.5 h after treatments. By contrast, HbMlo12 expression was downregulated by methyl jasmonate, abscisic acid, and drought stress treatments. There was no significant change in HbMlo12 expression after indole-3-acetic acid, H2O2, and wounding stimuli. Taken together, these results suggested that HbMlo12 might be a candidate Mlo gene conferring susceptibility to powdery mildew in rubber tree. The results of this study are vital in understanding Mlo gene evolution and developing new rubber tree varieties with powdery mildew resistance using reverse genetics.

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