scholarly journals Elucidation of the hrp Clusters of Xanthomonas oryzae pv. oryzicola That Control the Hypersensitive Response in Nonhost Tobacco and Pathogenicity in Susceptible Host Rice

2006 ◽  
Vol 72 (9) ◽  
pp. 6212-6224 ◽  
Author(s):  
Li-fang Zou ◽  
Xing-ping Wang ◽  
Yong Xiang ◽  
Bing Zhang ◽  
Yu-Rong Li ◽  
...  
Keyword(s):  
Hypersensitive Response ◽  
Inducible Promoter ◽  
Xanthomonas Oryzae ◽  
Complementation Test ◽  
Bacterial Leaf Streak ◽  
Rice Seedlings ◽  
Susceptible Host ◽  
The Core ◽  
Cluster A ◽  
Regulatory Cluster

ABSTRACT Xanthomonas oryzae pv. oryzicola, the cause of bacterial leaf streak in rice, possesses clusters of hrp genes that determine its ability to elicit a hypersensitive response (HR) in nonhost tobacco and pathogenicity in host rice. A 27-kb region of the genome of X. oryzae pv. oryzicola (RS105) was identified and sequenced, revealing 10 hrp, 9 hrc (hrp conserved), and 8 hpa (hrp-associated) genes and 7 regulatory plant-inducible promoter boxes. While the region from hpa2 to hpaB and the hrpF operon resembled the corresponding genes of other xanthomonads, the hpaB-hrpF region incorporated an hrpE3 gene that was not present in X. oryzae pv. oryzae. We found that an hrpF mutant had lost the ability to elicit the HR in tobacco and pathogenicity in adult rice plants but still caused water-soaking symptoms in rice seedlings and that Hpa1 is an HR elicitor in nonhost tobacco whose expression is controlled by an hrp regulator, HrpX. Using an Hrp phenotype complementation test, we identified a small hrp cluster containing the hrpG and hrpX regulatory genes, which is separated from the core hrp cluster. In addition, we identified a gene, prhA (plant-regulated hrp), that played a key role in the Hrp phenotype of X. oryzae pv. oryzicola but was neither in the core hrp cluster nor in the hrp regulatory cluster. A prhA mutant failed to reduce the HR in tobacco and pathogenicity in rice but caused water-soaking symptoms in rice. This is the first report that X. oryzae pv. oryzicola possesses three separate DNA regions for HR induction in nonhost tobacco and pathogenicity in host rice, which will provide a fundamental base to understand pathogenicity determinants of X. oryzae pv. oryzicola compared with those of X. oryzae pv. oryzae.

scholarly journals A Novel Regulatory Role of HrpD6 in Regulating hrp-hrc-hpa Genes in Xanthomonas oryzae pv. oryzicola

2011 ◽  
Vol 24 (9) ◽  
pp. 1086-1101 ◽  
Author(s):  
Yu-Rong Li ◽  
Hua-Song Zou ◽  
Yi-Zhou Che ◽  
Yi-Ping Cui ◽  
Wei Guo ◽  
...  
Keyword(s):  
Hypersensitive Response ◽  
Type Iii Secretion ◽  
Xanthomonas Oryzae ◽  
Host Cells ◽  
Bacterial Leaf Streak ◽  
Two Component System ◽  
Tal Effectors ◽  
Master Regulators ◽  
Hrp Genes

Xanthomonas oryzae pv. oryzicola, the causal agent of bacterial leaf streak in the model plant rice, possesses a hypersensitive response and pathogenicity (hrp), hrp-conserved (hrc), hrp-associated (hpa) cluster (hrp-hrc-hpa) that encodes a type III secretion system (T3SS) through which T3SS effectors are injected into host cells to cause disease or trigger plant defenses. Mutations in this cluster usually abolish the bacterial ability to cause hypersensitive response in nonhost tobacco and pathogenicity in host rice. In Xanthomonas spp., these genes are generally assumed to be regulated by the key master regulators HrpG and HrpX. However, we present evidence that, apart from HrpG and HrpX, HrpD6 is also involved in regulating the expression of hrp genes. Interestingly, the expression of hpa2, hpa1, hpaB, hrcC, and hrcT is positively controlled by HrpD6. Transcriptional expression assays demonstrated that the expression of the hrcC, hrpD5, hrpE, and hpa3 genes was not completely abolished by hrpG and hrpX mutations. As observed in analysis of their corresponding mutants, HrpG and HrpX exhibit contrasting gene regulation, particularly for hpa2 and hrcT. Other two-component system regulators (Zur, LrpX, ColR/S, and Trh) did not completely inhibit the expression of hrcC, hrpD5, hrpE, and hpa3. Immunoblotting assays showed that the secretion of HrpF, which is an HpaB-independent translocator, is not affected by the mutation in hrpD6. However, the mutation in hrpD6 affects the secretion of an HpaB-dependent TAL effector, AvrXa27. These novel findings suggest that, apart from HrpG and HrpX, HrpD6 plays important roles not only in the regulation of hrp genes but also in the secretion of TAL effectors.

scholarly journals The Activity of Lipid A and Core Components of Bacterial Lipopolysaccharides in the Prevention of the Hypersensitive Response in Pepper

1997 ◽  
Vol 10 (7) ◽  
pp. 926-928 ◽  
Author(s):  
Mari-Anne Newman ◽  
Michael J. Daniels ◽  
J. Maxwell Dow
Keyword(s):  
Hypersensitive Response ◽  
Xanthomonas Campestris ◽  
Lipid A ◽  
Enteric Bacteria ◽  
Core Oligosaccharide ◽  
The Core ◽  
Minimal Structure ◽  
Core Components ◽  
Pre Treatment ◽  
Bacterial Lipopolysaccharides

Pre-treatment of leaves of pepper (Capsicum annuum) with lipopolysaccharide (LPS) preparations from enteric bacteria and Xanthomonas campestris could prevent the hypersensitive response caused by an avirulent X. campestris strain. By use of a range of deep-rough mutants, the minimal structure in Salmonella LPS responsible for the elicitation of this effect was determined to be lipid A attached to a disaccharide of 2-keto-3-deoxyoctulosonate; lipid A alone and the free core oligosaccharide from a Salmonella Ra mutant were not effective. For Xanthomonas, the core oligosaccharide alone had activity although lipid A was not effective. The results suggest that pepper cells can recognize different structures within bacterial LPS to trigger alterations in plant response to avirulent pathogens.

scholarly journals Confirmation of Bacterial Leaf Streak of Rice Caused by Xanthomonas oryzae pv. oryzicola in Vietnam

Plant Disease ◽  
2015 ◽  
Vol 99 (12) ◽  
pp. 1853-1853 ◽  
Author(s):  
T. T. Tran ◽  
N. V. Nga ◽  
P. T. Ngan ◽  
N. T. Hong ◽  
B. Szurek ◽  
...  
Keyword(s):  
Xanthomonas Oryzae ◽  
Bacterial Leaf Streak

scholarly journals Discovery of Novel Dihydrolipoamide S-Succinyltransferase Inhibitors Based on Fragment Virtual Screening

2021 ◽  
Vol 22 (23) ◽  
pp. 12953
Author(s):  
Chengqian Wei ◽  
Junjie Huang ◽  
Yu Wang ◽  
Yifang Chen ◽  
Xin Luo ◽  
...  
Keyword(s):  
Virtual Screening ◽  
Antibacterial Agents ◽  
High Efficiency ◽  
Leaf Blight ◽  
Xanthomonas Oryzae ◽  
Bacterial Leaf Blight ◽  
Extracellular Polysaccharides ◽  
Bacterial Leaf Streak ◽  
Bacterial Diseases ◽  
Sulfone Derivatives

A series of new oxadiazole sulfone derivatives containing an amide moiety was synthesized based on fragment virtual screening to screen high-efficiency antibacterial agents for rice bacterial diseases. All target compounds showed greater bactericidal activity than commercial bactericides. 3-(4-fluorophenyl)-N-((5-(methylsulfonyl)-1,3,4-oxadiazol-2-yl)methyl)acrylamide (10) showed excellent antibacterial activity against Xanthomonas oryzae pv. oryzae and Xanthomonas oryzae pv. oryzicola, with EC50 values of 0.36 and 0.53 mg/L, respectively, which were superior to thiodiazole copper (113.38 and 131.54 mg/L) and bismerthiazol (83.07 and 105.90 mg/L). The protective activity of compound 10 against rice bacterial leaf blight and rice bacterial leaf streak was 43.2% and 53.6%, respectively, which was superior to that of JHXJZ (34.1% and 26.4%) and thiodiazole copper (33.0% and 30.2%). The curative activity of compound 10 against rice bacterial leaf blight and rice bacterial leaf streak was 44.5% and 51.7%, respectively, which was superior to that of JHXJZ (32.6% and 24.4%) and thiodiazole copper (27.1% and 28.6%). Moreover, compound 10 might inhibit the growth of Xanthomonas oryzae pv. oryzae and Xanthomonas oryzae pv. oryzicola by affecting the extracellular polysaccharides, destroying cell membranes, and inhibiting the enzyme activity of dihydrolipoamide S-succinyltransferase.

Occurrence of Xanthomonas oryzae pv. oryzicola causing bacterial leaf streak disease of rice in different state of Malaysia

2019 ◽  
Vol 101 (3) ◽  
pp. 785-786
Author(s):  
Erneeza Mohd Hata ◽  
Kamaruzaman Sijam ◽  
Mohd Termizi Yusof ◽  
Dzarifah Zulperi
Keyword(s):  
Xanthomonas Oryzae ◽  
Bacterial Leaf Streak

scholarly journals Transcriptional Profiling of Rice Leaves Undergoing a Hypersensitive Response Like Reaction Induced by Xanthomonas oryzae pv. oryzae Cellulase

Rice ◽  
2009 ◽  
Vol 3 (1) ◽  
pp. 1-21 ◽  
Author(s):  
Gopaljee Jha ◽  
Hitendra Kumar Patel ◽  
Madhumita Dasgupta ◽  
Ramesh Palaparthi ◽  
Ramesh V. Sonti
Keyword(s):  
Hypersensitive Response ◽  
Transcriptional Profiling ◽  
Xanthomonas Oryzae ◽  
Rice Leaves

scholarly journals Novel Candidate Virulence Factors in Rice Pathogen Xanthomonas oryzae pv. oryzicola as Revealed by Mutational Analysis

2007 ◽  
Vol 73 (24) ◽  
pp. 8023-8027 ◽  
Author(s):  
Li Wang ◽  
Seiko Makino ◽  
Ashim Subedee ◽  
Adam J. Bogdanove
Keyword(s):  
Virulence Factors ◽  
Mutational Analysis ◽  
Xanthomonas Oryzae ◽  
Quantitative Assay ◽  
Bacterial Leaf Streak ◽  
Phytopathogenic Bacteria ◽  
Animal Pathogens ◽  
Important Disease

ABSTRACT Bacterial leaf streak, caused by Xanthomonas oryzae pv. oryzicola, is an important disease of rice. Transposon-mediated mutational analysis of the pathogen with a quantitative assay revealed candidate virulence factors including genes involved in the pathogenesis of other phytopathogenic bacteria, virulence factors of animal pathogens, and genes not previously associated with virulence.

scholarly journals CatB is Critical for Total Catalase Activity and Reduces Bactericidal Effects of Phenazine-1-Carboxylic Acid on Xanthomonas oryzae pv. oryzae and X. oryzae pv. oryzicola

2017 ◽  
Vol 107 (2) ◽  
pp. 163-172 ◽  
Author(s):  
Xiayan Pan ◽  
Jian Wu ◽  
Shu Xu ◽  
Yabing Duan ◽  
Mingguo Zhou
Keyword(s):  
Carboxylic Acid ◽  
Catalase Activity ◽  
Redox Balance ◽  
Xanthomonas Oryzae ◽  
Deletion Mutants ◽  
Oxygen Species ◽  
Bacterial Leaf Streak ◽  
Induced Stress ◽  
Bactericidal Effects ◽  
Increased Sensitivity

Rice bacterial leaf blight, caused by Xanthomonas oryzae pv. oryzae, and rice bacterial leaf streak, caused by X. oryzae pv. oryzicola, are major diseases of rice. Phenazine-1-carboxylic acid (PCA) is a natural product that is isolated from Pseudomonas spp. and is used to control many important rice diseases in China. We previously reported that PCA disturbs the redox balance, which results in the accumulation of reactive oxygen species in X. oryzae pv. oryzae. In this study, we found that PCA significantly upregulated the transcript levels of catB and katE, which encode catalases, and that PCA sensitivity was reduced when X. oryzae pvs. oryzae and oryzicola were cultured with exogenous catalase. Furthermore, catB deletion mutants of X. oryzae pvs. oryzae and oryzicola showed dramatically decreased total catalase activity, increased sensitivity to PCA, and reduced virulence in rice. In contrast, deletion mutants of srpA and katG, which also encode catalases, exhibited little change in PCA sensitivity. The results indicate that catB in both X. oryzae pvs. oryzae and oryzicola encodes a catalase that helps protect the bacteria against PCA-induced stress.

scholarly journals Identification of Two Novelhrp-Associated Genes in the hrp Gene Cluster ofXanthomonas oryzae pv. oryzae

2000 ◽  
Vol 182 (7) ◽  
pp. 1844-1853 ◽  
Author(s):  
Weiguang Zhu ◽  
Mark M. MaGbanua ◽  
Frank F. White
Keyword(s):  
Nucleotide Sequence ◽  
Gene Cluster ◽  
Hypersensitive Response ◽  
Xanthomonas Campestris ◽  
Host Plants ◽  
Xanthomonas Oryzae ◽  
Insertion Element ◽  
Nonhost Plant ◽  
Rice Leaves ◽  
Glycine Rich Protein

ABSTRACT We have cloned a hrp gene cluster fromXanthomonas oryzae pv. oryzae. Bacteria with mutations in the hrp region have reduced growth in rice leaves and lose the ability to elicit a hypersensitive response (HR) on the appropriate resistant cultivars of rice and the nonhost plant tomato. A 12,165-bp portion of nucleotide sequence from the presumed left end and extending through the hrpB operon was determined. The region was most similar to hrp genes from Xanthomonas campestris pv. vesicatoria and Ralstonia solanacearum. Two new hrp-associated loci, namedhpa1 and hpa2, were located beyond thehrpA operon. The hpa1 gene encoded a 13-kDa glycine-rich protein with a composition similar to those of harpins and PopA. The product of hpa2 was similar to lysozyme-like proteins. Perfect PIP boxes were present in the hrpB andhpa1 operons, while a variant PIP box was located upstream of hpa2. A strain with a deletion encompassinghpa1 and hpa2 had reduced pathogenicity and elicited a weak HR on nonhost and resistant host plants. Experiments using single mutations in hpa1 and hpa2indicated that the loss of hpa1 was the principal cause of the reduced pathogenicity of the deletion strain. A 1,519-bp insertion element was located immediately downstream of hpa2. Hybridization with hpa2 indicated that the gene was present in all of the strains of Xanthomonas examined. Hybridization experiments with hpa1 and IS1114indicated that these sequences were detectable in all strains ofX. oryzae pv. oryzae and some other Xanthomonasspecies.

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