scholarly journals Genome Resource of a Hypervirulent Strain LN4 of Xanthomonas oryzae pv. oryzae Causing Bacterial Blight of Rice

Plant Disease ◽  
2020 ◽  
Vol 104 (11) ◽  
pp. 2764-2767
Author(s):  
Zhengyin Xu ◽  
Sai Wang ◽  
Liang Liu ◽  
Yangyang Yang ◽  
Bo Zhu ◽  
...  
Keyword(s):  
Bacterial Blight ◽  
Xanthomonas Oryzae ◽  
Nanopore Sequencing ◽  
Transcription Activator ◽  
Rice Varieties ◽  
Single Chromosome ◽  
Coding Sequences ◽  
Genome Data ◽  
Bacterial Blight Of Rice ◽  
Virulence Effectors

Xanthomonas oryzae pv. oryzae is the causative agent of bacterial blight of rice and causes severe harvest loss and challenges to a stable food supply globally. In this study, a hypervirulent strain, LN4, compatible in rice varieties carrying Xa3, Xa4, xa13, and xa25 resistance genes, was used to generate DNA for nanopore sequencing. After assembly, the genome comprises a single chromosome of 5,012,583 bp, consisting of a total of 6,700 predicted coding sequences. Seventeen transcription activator-like effectors (TALEs) were encoded in the genome, of which two (Tal7 and Tal6c) were major TALEs. The approach and genome data provide information for the discovery of new virulence effectors and understanding of the virulence mechanism of TALEs in rice.

scholarly journals Genome Resource of a Hypervirulent Strain C9-3 of Xanthomonas oryzae pv. oryzae Causing Bacterial Blight of Rice

Plant Disease ◽  
2021 ◽  
Author(s):  
Xiao-Lin Chen ◽  
Qili Li ◽  
Jinkai Wang ◽  
Yu Zhang ◽  
Lihua Tang ◽  
...  
Keyword(s):  
Single Molecule ◽  
Genomic Dna ◽  
Bacterial Blight ◽  
Xanthomonas Oryzae ◽  
Transcription Activator ◽  
Smrt Sequencing ◽  
Circular Chromosome ◽  
Bacterial Blight Of Rice ◽  
Single Circular Chromosome ◽  
Virulence Effectors

Xanthomonas oryzae pv. oryzae is the causal agent of bacterial blight, one of the most devastating diseases of rice. Here, a hypervirulent strain, C9-3, defeating Xa1、Xa10、xa13 and Xa23 resistance genes, was used to extract genomic DNA for single molecule real-time (SMRT) sequencing. After assembly, the genome consists of a single-circular chromosome with the size of 4,924,298 bp with G+C content of 63.7%, and contains 4715 genes. Annotation and analysis of the TALE genes using a suite of application named AnnoTALE suggested that 17 transcription activator-like effectors, including 15 typical TALEs and 2 iTALEs/truncTALEs, were encoded in the genome. The approach and genome resource will contribute to the discovery of new virulence effectors and understanding on rice-X. oryzae pv. oryzae interactions.

scholarly journals Mutagenesis of 18 Type III Effectors Reveals Virulence Function of XopZPXO99 in Xanthomonas oryzae pv. oryzae

2010 ◽  
Vol 23 (7) ◽  
pp. 893-902 ◽  
Author(s):  
Congfeng Song ◽  
Bing Yang
Keyword(s):  
Bacterial Blight ◽  
Xanthomonas Oryzae ◽  
Host Cells ◽  
Lesion Length ◽  
Transcription Activator ◽  
Tal Effectors ◽  
Type Iii ◽  
Effector Genes ◽  
Acid Protein ◽  
Bacterial Blight Of Rice

Xanthomonas oryzae pv. oryzae depends on a type III secretion system (T3SS) to translocate effectors into host cells for its ability to cause bacterial blight of rice. All type III (T3) effectors with known function in X. oryzae pv. oryzae belong to a family of transcription activator-like (TAL) effectors. However, other, non–TAL-related effector genes are present in the genome, although their role in virulence and their mode of action have yet to be elucidated. Here, we report the generation of mutants for 18 non-TAL T3 effector genes and the identification of one that contributes to the virulence of strain PXO99A. XopZPXO99 encodes a predicted 1,414-amino-acid protein of unknown function. PXO99A contains two identical copies of the gene due to a duplication of 212 kb in the genome. Strains with knockout mutations of one copy of XopZPXO99 did not exhibit any visible virulence defect. However, strains with mutations in both copies of XopZPXO99 displayed reduced virulence in terms of lesion length and bacterial multiplication compared with PXO99A. The introduction of one genomic copy of XopZPXO99 restores the mutant to full virulence. Transient expression of XopZPXO99 in Nicotiana benthamiana leaves suppresses host basal defense, which is otherwise induced by a T3SS mutant of PXO99A, suggesting a role for XopZPXO99 in interfering with host innate immunity during X. oryzae pv. oryzae infection. XopZPXO99-related genes are found in all Xanthomonas spp. whose genomic sequences have been determined, suggesting a conserved role for this type of effector gene in pathogenesis of Xanthomonas spp. Our results indicate that XopZPXO99 encodes a novel T3 effector and contributes virulence to X. oryzae pv. oryzae strains for bacterial blight of rice.

scholarly journals Engineering Resistance to Bacterial Blight and Bacterial Leaf Streak in Rice

Rice ◽  
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.

scholarly journals The Type III Accessory Protein HrpE of Xanthomonas oryzae pv. oryzae Surpasses the Secretion Role, and Enhances Plant Resistance and Photosynthesis

2019 ◽  
Vol 7 (11) ◽  
pp. 572
Author(s):  
Taha Sheikh ◽  
Liyuan Zhang ◽  
Muhammad Zubair ◽  
Alvina Hanif ◽  
Ping Li ◽  
...  
Keyword(s):  
Bacterial Blight ◽  
Xanthomonas Oryzae ◽  
Accessory Protein ◽  
Transcription Activator ◽  
Tal Effectors ◽  
Rice Varieties ◽  
Type Iii ◽  
Photosynthesis Efficiency ◽  
Blight Disease ◽  
Effector Secretion

Many species of plant-pathogenic gram-negative bacteria deploy the type III (T3) secretion system to secrete virulence components, which are mostly characteristic of protein effectors targeting the cytosol of the plant cell following secretion. Xanthomonas oryzae pv. oryzae (Xoo), a rice pathogen causing bacterial blight disease, uses the T3 accessory protein HrpE to assemble the pilus pathway, which in turn secretes transcription activator-like (TAL) effectors. The hrpE gene can execute extensive physiological and pathological functions beyond effector secretion. As evidenced in this study, when the hrpE gene was deleted from the Xoo genome, the bacteria incur seriouimpairments in multiplication, motility, and virulence. The virulence nullification is attributed to reduced secretion and translocation of PthXo1, which is a TAL effector that determines the bacterial virulence in the susceptible rice varieties. When the HrpE protein produced by prokaryotic expression is applied to plants, the recombinant protein is highly effective at inducing the defense response. Moreover, leaf photosynthesis efficiency is enhanced in HrpE-treated plants. These results provide experimental avenues to modulate the plant defense and growth tradeoff by manipulating a bacterial T3 accessory protein.

scholarly journals The Role of a Host-Induced Arginase of Xanthomonas oryzae pv. oryzae in Promoting Virulence on Rice

2019 ◽  
Vol 109 (11) ◽  
pp. 1869-1877
Author(s):  
Yuqiang Zhang ◽  
Guichun Wu ◽  
Ian Palmer ◽  
Bo Wang ◽  
Guoliang Qian ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Bacterial Blight ◽  
Wild Type Strain ◽  
Bacterial Pathogen ◽  
Extracellular Polysaccharide ◽  
Rice Cultivar ◽  
Xanthomonas Oryzae ◽  
Wild Type ◽  
Bacterial Blight Of Rice

The plant bacterial pathogen Xanthomonas oryzae pv. oryzae causes bacterial blight of rice, which is one of the most destructive rice diseases prevalent in Asia and parts of Africa. Despite many years of research, how X. oryzae pv. oryzae causes bacterial blight of rice is still not completely understood. Here, we show that the loss of the rocF gene caused a significant decrease in the virulence of X. oryzae pv. oryzae in the susceptible rice cultivar IR24. Bioinformatics analysis demonstrated that rocF encodes arginase. Quantitative real-time PCR and Western blot assays revealed that rocF expression was significantly induced by rice and arginine. The rocF deletion mutant strain showed elevated sensitivity to hydrogen peroxide, reduced extracellular polysaccharide (EPS) production, and reduced biofilm formation, all of which are important determinants for the full virulence of X. oryzae pv. oryzae, compared with the wild-type strain. Taken together, the results of this study revealed a mechanism by which a bacterial arginase is required for the full virulence of X. oryzae pv. oryzae on rice because of its contribution to tolerance to reactive oxygen species, EPS production, and biofilm formation.

scholarly journals Cloning of the rice Xo1 resistance gene and interaction of the Xo1 protein with the defense-suppressing Xanthomonas effector Tal2h

2020 ◽  
Author(s):  
Andrew C. Read ◽  
Mathilde Hutin ◽  
Matthew J. Moscou ◽  
Fabio C. Rinaldi ◽  
Adam J. Bogdanove
Keyword(s):  
Resistance Gene ◽  
Resistance Genes ◽  
Bacterial Blight ◽  
Rice Variety ◽  
Susceptible Variety ◽  
Xanthomonas Oryzae ◽  
Physical Interaction ◽  
Bacterial Leaf Streak ◽  
Transcription Activator ◽  
Rice Leaves

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.

Allelochemical catechol comprehensively impedes bacterial blight of rice caused by Xanthomonas oryzae pv. oryzae

2020 ◽  
Vol 149 ◽  
pp. 104559
Author(s):  
Kumari Vishakha ◽  
Shatabdi Das ◽  
Satarupa Banerjee ◽  
Sandhimita Mondal ◽  
Arnab Ganguli
Keyword(s):  
Bacterial Blight ◽  
Xanthomonas Oryzae ◽  
Bacterial Blight Of Rice

TALE-triggered and iTALE-suppressed Xa1 resistance to bacterial blight is independent of OsTFIIAγ1 or OsTFIIAγ5 in rice

2021 ◽  
Author(s):  
Xiameng Xu ◽  
Zhengyin Xu ◽  
Wenxiu Ma ◽  
Fazal Haq ◽  
Ying Li ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Transgenic Plants ◽  
Expression Pattern ◽  
Bacterial Blight ◽  
Susceptibility Genes ◽  
Xanthomonas Oryzae ◽  
Transcription Activator ◽  
Rice Bacterial Blight ◽  
Unknown Factor ◽  
Biomolecular Fluorescence Complementation

Abstract Xa1-mediated resistance to rice bacterial blight, caused by Xanthomonas oryzae pv. oryzae (Xoo), is triggered by transcription activator-like effectors (TALEs) and suppressed by interfering TALEs (iTALEs). TALEs interact with the rice transcription factor OsTFIIAγ1 or OsTFIIAγ5 (Xa5) to transcriptionally activate expression of target resistance and/or susceptibility genes. However, it is not clear whether OsTFIIAγ is involved in TALE-triggered and iTALE-suppressed Xa1 resistance. In this study, genome-edited mutations in OsTFIIAγ5 or OsTFIIAγ1 of Xa1-containing rice IRBB1 and Xa1-transgenic plants of xa5-containing rice IRBB5 did not impair the activation or suppression of Xa1 resistance. Correspondingly, the expression pattern of Xa1 in mutated OsTFIIAγ5 and OsTFIIAγ1 rice lines and IRBB1 rice was similar. In contrast, the expression of OsSWEET11 was repressed in mutated OsTFIIAγ5 and OsTFIIAγ1 rice lines. Biomolecular fluorescence complementation (BiFC) and co-immunoprecipitation (Co-IP) showed that both the TALE PthXo1 and iTALE Tal3a interacted with OsTFIIAγ1 and OsTFIIAγ5 in plant nuclei. These results indicate that TALE-triggered and iTALE-suppressed Xa1 resistance to BB is independent of OsTFIIAγ1 or OsTFIIAγ5 in rice and suggest that an unknown factor is potentially involved in the interaction of Xa1, TALEs and iTALEs in rice.

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