Reclassification of the Causal Agents of Bacterial Blight (Xanthomonas campestris pv. oryzae) and Bacterial Leaf Streak (Xanthomonas campestris pv. oryzicola) of Rice as Pathovars of Xanthomonas oryzae (ex Ishiyama 1922) sp. nov., nom. rev.

AbstractThe Xo1 locus in the heirloom rice variety Carolina Gold Select confers resistance to bacterial leaf streak and bacterial blight, caused by Xanthomonas oryzae pvs. oryzicola and oryzae, respectively. Resistance is triggered by pathogen-delivered transcription activator-like effectors (TALEs) independent of their ability to activate transcription, and is suppressed by variants called truncTALEs common among Asian strains. By transformation of the susceptible variety Nipponbare, we show that one of 14 nucleotide-binding, leucine-rich repeat (NLR) protein genes at the locus, with a zfBED domain, is the Xo1 gene. Analyses of published transcriptomes revealed that the Xo1-mediated response is similar to those of NLR resistance genes Pia and Rxo1 and distinct from that associated with induction of the executor resistance gene Xa23, and that a truncTALE dampens or abolishes activation of defense-associated genes by Xo1. In Nicotiana benthamiana leaves, fluorescently-tagged Xo1 protein, like TALEs and truncTALEs, localized to the nucleus. And, endogenous Xo1 specifically co-immunoprecipitated from rice leaves with a pathogen-delivered, epitope-tagged truncTALE. These observations suggest that suppression of Xo1-function by truncTALEs occurs through direct or indirect physical interaction. They further suggest that effector co-immunoprecipitation may be effective for identifying or characterizing other resistance genes.

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Rice Routes of Countering Xanthomonas oryzae

International Journal of Molecular Sciences ◽

10.3390/ijms19103008 ◽

2018 ◽

Vol 19 (10) ◽

pp. 3008 ◽

Cited By ~ 9

Author(s):

Zhiyuan Ji ◽

Chunlian Wang ◽

Kaijun Zhao

Keyword(s):

Bacterial Blight ◽

Xanthomonas Oryzae ◽

R Genes ◽

Bacterial Leaf Streak ◽

Crop Breeding ◽

Environment Friendly ◽

The Past ◽

Pathogen Effectors ◽

Plant Pathogen Interaction ◽

Diverse Interactions

Bacterial blight (BB) and bacterial leaf streak (BLS), caused by Xanthomonas oryzae pv. oryzae and Xanthomonas oryzae pv. oryzicola, respectively, are two devastating diseases in rice planting areas worldwide. It has been proven that adoption of rice resistance is the most effective, economic, and environment-friendly strategy to avoid yield loss caused by BB and BLS. As a model system for plant—pathogen interaction, the rice—X. oryzae pathosystem has been intensively investigated in the past decade. Abundant studies have shown that the resistance and susceptibility of rice to X. oryzae is determined by molecular interactions between rice genes or their products and various pathogen effectors. In this review, we briefly overviewed the literature regarding the diverse interactions, focusing on recent advances in uncovering mechanisms of rice resistance and X. oryzae virulence. Our analysis and discussions will not only be helpful for getting a better understanding of coevolution of the rice innate immunity and X. oryzae virulence, but it will also provide new insights for application of plant R genes in crop breeding.

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Efficacy of bacteriocinogenic strains of Xanthomonas oryzae pv. oryzae on the incidence of bacterial blight disease of rice (Oryza sativa L.)

Canadian Journal of Microbiology ◽

10.1139/m91-131 ◽

1991 ◽

Vol 37 (10) ◽

pp. 764-768 ◽

Cited By ~ 11

Author(s):

N. Sakthivel ◽

T. W. Mew

Keyword(s):

Biological Control ◽

Bacterial Blight ◽

Oryza Sativa L ◽

Disease Incidence ◽

Bacteriocin Production ◽

Xanthomonas Oryzae ◽

Control Treatment ◽

Bacterial Leaf Streak ◽

Blight Disease ◽

Greenhouse Tests

A total of 144 isolates of Xanthomonas oryzae pv. oryzae were screened for bacteriocin production against 30 indicator strains of X. oryzae pv. oryzae. Forty isolates showed broad-spectrum inhibitory activity against 20–27 indicators, presumably because of the production of bacteriocin compounds. The selected isolates were screened for bacteriocin production at 29 °C and tested for virulence on rice differentials. Since all of the isolates were pathogenic, nonpathogenic bacteria were generated through N-methyl-N-nitro-N-nitrosoguanidine mutagenesis and by repeated subculturing. Epiphytic colonization and survival of pathogens and of nonpathogenic bacteriocin producers on rice plants were monitored, using mutants resistant to streptomycin and rifampicin. An improved method of pathogen inoculation was developed and used to evaluate biological control. Treatment with nonpathogenic bacteriocin-producing bacteria resulted in reductions of bacterial blight incidence up to 31–99% in greenhouse tests and 11–73% in the screenhouse. Bacterial leaf streak severity was reduced 4–20% in the greenhouse and disease incidence was reduced 20–39% in the screenhouse. Key words: bacteriocin, biological control, Xanthomonas oryzae pv. oryzae, mutagenesis, rice.

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Resistance Genes and their Interactions with Bacterial Blight/Leaf Streak Pathogens (Xanthomonas oryzae) in Rice (Oryza sativa L.)—an Updated Review

Rice ◽

10.1186/s12284-019-0358-y ◽

2020 ◽

Vol 13 (1) ◽

Cited By ~ 11

Author(s):

Nan Jiang ◽

Jun Yan ◽

Yi Liang ◽

Yanlong Shi ◽

Zhizhou He ◽

...

Keyword(s):

Oryza Sativa ◽

Bacterial Blight ◽

Oryza Sativa L ◽

Rice Production ◽

Xanthomonas Oryzae ◽

Bacterial Leaf Streak ◽

Viral Pathogens ◽

Effector Genes ◽

Broad Spectrum Resistance ◽

Genomic Studies

AbstractRice (Oryza sativa L.) is a staple food crop, feeding more than 50% of the world’s population. Diseases caused by bacterial, fungal, and viral pathogens constantly threaten the rice production and lead to enormous yield losses. Bacterial blight (BB) and bacterial leaf streak (BLS), caused respectively by gram-negative bacteria Xanthomonas oryzae pv. oryzae (Xoo) and Xanthomonas oryzae pv. oryzicola (Xoc), are two important diseases affecting rice production worldwide. Due to the economic importance, extensive genetic and genomic studies have been conducted to elucidate the molecular mechanism of rice response to Xoo and Xoc in the last two decades. A series of resistance (R) genes and their cognate avirulence and virulence effector genes have been characterized. Here, we summarize the recent advances in studies on interactions between rice and the two pathogens through these R genes or their products and effectors. Breeding strategies to develop varieties with durable and broad-spectrum resistance to Xanthomonas oryzae based on the published studies are also discussed.

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Engineering Resistance to Bacterial Blight and Bacterial Leaf Streak in Rice

Rice ◽

10.1186/s12284-021-00482-z ◽

2021 ◽

Vol 14 (1) ◽

Author(s):

Zhe Ni ◽

Yongqiang Cao ◽

Xia Jin ◽

Zhuomin Fu ◽

Jianyuan Li ◽

...

Keyword(s):

Bacterial Blight ◽

Agronomic Traits ◽

Susceptibility Gene ◽

Susceptibility Genes ◽

Xanthomonas Oryzae ◽

Bacterial Leaf Streak ◽

Transcription Activator ◽

Rice Varieties ◽

Simulated Field ◽

Bacterial Groups

Abstract Background Xanthomonas oryzae (Xo) is one of the important pathogenic bacterial groups affecting rice production. Its pathovars Xanthomonas oryzae pv. oryzae (Xoo) and Xanthomonas oryzae pv. oryzicola (Xoc) cause bacterial blight and bacterial leaf streak in rice, respectively. Xo infects host plants by relying mainly on its transcription activator-like effectors (TALEs) that bind to host DNA targets, named effector binding elements (EBEs), and induce the expression of downstream major susceptibility genes. Blocking TALE binding to EBE could increase rice resistance to the corresponding Xo. Findings We used CRISPR/Cas9 to edit the EBEs of three major susceptibility genes (OsSWEET11, OsSWEET14 and OsSULTR3;6) in the rice varieties Guihong 1 and Zhonghua 11. Both varieties have a natural one-base mutation in the EBE of another major susceptibility gene (OsSWEET13) which is not induced by the corresponding TALE. Two rice lines GT0105 (from Guihong 1) and ZT0918 (from Zhonghua 11) with target mutations and transgene-free were obtained and showed significantly enhanced resistance to the tested strains of Xoo and Xoc. Furthermore, under simulated field conditions, the morphology and other agronomic traits of GT0105 and ZT0918 were basically the same as those of the wild types. Conclusions In this study, we first reported that the engineering rice lines obtained by editing the promoters of susceptibility genes are resistant to Xoo and Xoc, and their original agronomic traits are not affected.

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Genomics-Based Diagnostic Marker Development for Xanthomonas oryzae pv. oryzae and X. oryzae pv. oryzicola

Plant Disease ◽

10.1094/pdis-94-3-0311 ◽

2010 ◽

Vol 94 (3) ◽

pp. 311-319 ◽

Cited By ~ 63

Author(s):

Jillian M. Lang ◽

John P. Hamilton ◽

Maria Genaleen Q. Diaz ◽

Marie Anne Van Sluys ◽

Ma. Ruby G. Burgos ◽

...

Keyword(s):

Bacterial Blight ◽

Plant Pathogens ◽

Diagnostic Marker ◽

Xanthomonas Oryzae ◽

Bacterial Leaf Streak ◽

Chain Reaction ◽

Associated Bacteria ◽

Rice Bacterial Blight ◽

Polymerase Chain ◽

Genome Comparisons

A computational genomics pipeline was used to compare sequenced genomes of Xanthomonas spp. and to rapidly identify unique regions for development of highly specific diagnostic markers. A suite of diagnostic primers was selected to monitor diverse loci and to distinguish the rice bacterial blight and bacterial leaf streak pathogens, Xanthomonas oryzae pv. oryzae and X. oryzae pv. oryzicola, respectively. A subset of these primers was combined into a multiplex polymerase chain reaction set that accurately distinguished the two rice pathogens in a survey of a geographically diverse collection of X. oryzae pv. oryzae, X. oryzae pv. oryzicola, other xanthomonads, and several genera of plant-pathogenic and plant- or seed-associated bacteria. This computational approach for identification of unique loci through whole-genome comparisons is a powerful tool that can be applied to other plant pathogens to expedite development of diagnostic primers.

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The RpfB-Dependent Quorum Sensing Signal Turnover System Is Required for Adaptation and Virulence in Rice Bacterial Blight Pathogen Xanthomonas oryzae pv. oryzae

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi-09-15-0206-r ◽

2016 ◽

Vol 29 (3) ◽

pp. 220-230 ◽

Cited By ~ 23

Author(s):

Xing-Yu Wang ◽

Lian Zhou ◽

Jun Yang ◽

Guang-Hai Ji ◽

Ya-Wen He

Keyword(s):

Quorum Sensing ◽

Bacterial Blight ◽

Xanthomonas Campestris ◽

Deletion Mutant ◽

Extracellular Polysaccharide ◽

Xanthomonas Oryzae ◽

Rice Bacterial Blight ◽

Double Deletion ◽

Diffusible Signal Factor ◽

Bacterial Blight Pathogen

Xanthomonas oryzae pv. oryzae, the bacterial blight pathogen of rice, produces diffusible signal factor (DSF) family quorum sensing signals to regulate virulence. The biosynthesis and perception of DSF family signals require components of the rpf (regulation of pathogenicity factors) cluster. In this study, we report that RpfB plays an essential role in DSF family signal turnover in X. oryzae pv. oryzae PXO99A. The production of DSF family signals was boosted by deletion of the rpfB gene and was abolished by its overexpression. The RpfC/RpfG-mediated DSF signaling system negatively regulates rpfB expression via the global transcription regulator Clp, whose activity is reversible in the presence of cyclic diguanylate monophosphate. These findings indicate that the DSF family signal turnover system in PXO99A is generally consistent with that in Xanthomonas campestris pv. campestris. Moreover, this study has revealed several specific roles of RpfB in PXO99A. First, the rpfB deletion mutant produced high levels of DSF family signals but reduced extracellular polysaccharide production, extracellular amylase activity, and attenuated pathogenicity. Second, the rpfB/rpfC double-deletion mutant was partially deficient in xanthomonadin production. Taken together, the RpfB-dependent DSF family signal turnover system is a conserved and naturally presenting signal turnover system in Xanthomonas spp., which plays unique roles in X. oryzae pv. oryzae adaptation and pathogenesis.

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Identification and Molecular Mapping of Xa32(t), a Novel Resistance Gene for Bacterial Blight (Xanthomonas oryzae pv. oryzae) in Rice

ACTA AGRONOMICA SINICA ◽

10.3724/sp.j.1006.2009.01173 ◽

2009 ◽

Vol 35 (7) ◽

pp. 1173-1180 ◽

Cited By ~ 6

Author(s):

Chong-Ke ZHENG ◽

Chun-Lian WANG ◽

Yuan-Jie YU ◽

Yun-Tao LIANG ◽

Kai-Jun ZHAO

Keyword(s):

Resistance Gene ◽

Bacterial Blight ◽

Molecular Mapping ◽

Xanthomonas Oryzae

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Coinoculation Effects of the Pathogens Causing Common Bacterial Blight, Rust, and Bean Common Mosaic in Phaseolus vulgaris

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.115.2.319 ◽

1990 ◽

Vol 115 (2) ◽

pp. 319-323 ◽

Cited By ~ 5

Author(s):

H.Z. Zaiter ◽

D.P. Coyne ◽

J.R. Steadman

Keyword(s):

Phaseolus Vulgaris ◽

Bacterial Blight ◽

Xanthomonas Campestris ◽

Bean Common Mosaic Virus ◽

Host Susceptibility ◽

Uromyces Appendiculatus ◽

Common Bacterial Blight ◽

Dry Bean ◽

Screening For Resistance ◽

Prior Infection

Ten dry bean (Phaseolus vulgaris L.) cultivars/lines with differential reactions to rust were used in growth chamber experiments to determine rust [Uromyces appendiculatus (Pers.) Unger var. appendiculutus, (U a)], and common bacterial blight Xanthomonas campestris pv. phaseoli (E.F. Sm.) Dews. (X c p)] reactions on leaves when coinoculated with both pathogens. The X c p-U a necrosis symptoms were very different from those caused by X c p alone. Depending on the level of host susceptibility to rust, the X c p reaction remained confined within the rust pustule or spread beyond the pustule area, causing a necrosis of the entire leaf. Prior infection of bean seedlings with bean common mosaic virus (BCMV), NY-15 strain, reduced rust pustule size, but did not affect the reaction to X c p. Screening with X c p and BCMV can be done at the same time during the early vegetative stage, but the interactions of U a with X c p and of BCMV with U a need to be considered in screening for resistance.

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