Analysis of Pathogenic Diversity of the Rice Bacterial Blight Pathogen (Xanthomonas oryzae pv. oryzae ) in the Andaman Islands and Identification of Effective Resistance Genes

2014 ◽  
Vol 163 (6) ◽  
pp. 423-432 ◽  
Author(s):  
Raj K. Gautam ◽  
Pankaj K. Singh ◽  
Krishnan Sakthivel ◽  
Muthulingam Srikumar ◽  
Naresh Kumar ◽  
...  
Keyword(s):  
Resistance Genes ◽  
Bacterial Blight ◽  
Effective Resistance ◽  
Xanthomonas Oryzae ◽  
Andaman Islands ◽  
Rice Bacterial Blight ◽  
Bacterial Blight Pathogen ◽  
Pathogenic Diversity

scholarly journals A strain of an emerging Indian pathotype of Xanthomonas oryzae pv. oryzae defeats the rice bacterial blight resistance gene xa13 without inducing a clade III SWEET gene and is nearly identical to a recent Thai isolate

2018 ◽  
Author(s):  
Sara C. D. Carpenter ◽  
Prashant Mishra ◽  
Chandrika Ghoshal ◽  
Prasanta Dash ◽  
Li Wang ◽  
...  
Keyword(s):  
Resistance Genes ◽  
Bacterial Blight ◽  
Xanthomonas Oryzae ◽  
Host Susceptibility ◽  
Transcription Activator ◽  
Rice Bacterial Blight ◽  
Indian Strain ◽  
Bacterial Blight Pathogen ◽  
Insight Into ◽  
S Genes

AbstractThe rice bacterial blight pathogen Xanthomonas oryzae pv. oryzae (Xoo) injects transcription activator-like effectors (TALEs) that bind and activate host ‘susceptibility’ (S) genes important for disease. Clade III SWEET genes are major S genes for bacterial blight. The resistance genes xa5, which reduces TALE activity generally, and xa13, a SWEET11 allele not recognized by the cognate TALE, have been effectively deployed. However, strains that defeat both resistance genes individually were recently reported in India and Thailand. To gain insight into the mechanism(s), we completely sequenced the genome of one such strain from each country and examined the encoded TALEs. Strikingly, the two strains are clones, sharing nearly identical TALE repertoires, including a TALE known to activate SWEET11 strongly enough to be effective even when diminished by xa5. We next investigated SWEET gene induction by the Indian strain. The Indian strain induced no clade III SWEET in plants harbouring xa13, indicating a pathogen adaptation that relieves dependence on these genes for susceptibility. The findings open a door to mechanistic understanding of the role SWEET genes play in susceptibility and illustrate the importance of complete genome sequence-based monitoring of Xoo populations in developing varieties with effective disease resistance.

Biological control of rice bacterial blight by plant-associated bacteria producing 2,4-diacetylphloroglucinol

2006 ◽  
Vol 52 (1) ◽  
pp. 56-65 ◽  
Author(s):  
Palaniyandi Velusamy ◽  
J Ebenezar Immanuel ◽  
Samuel S Gnanamanickam ◽  
Linda Thomashow
Keyword(s):  
Biological Control ◽  
Pseudomonas Fluorescens ◽  
Bacterial Blight ◽  
Field Experiments ◽  
Screening Method ◽  
Xanthomonas Oryzae ◽  
Rice Bacterial Blight ◽  
Fluorescent Pseudomonas ◽  
Tn5 Mutants ◽  
Bacterial Blight Pathogen

Certain plant-associated strains of fluorescent Pseudomonas spp. are known to produce the antimicrobial antibiotic 2,4-diacetylphloroglucinol (DAPG). It has antibacterial, antifungal, antiviral, and antihelminthic properties and has played a significant role in the biological control of tobacco, wheat, and sugar beet diseases. It has never been reported from India and has not been implicated in the biological suppression of a major disease of the rice crop. Here, we report that a subpopulation of 27 strains of plant-associated Pseudomonas fluorescens screened in a batch of 278 strains of fluorescent pseudomonads produced DAPG. The DAPG production was detected by a PCR-based screening method that used primers Phl2a and Phl2b and amplified a 745-bp fragment characteristic of DAPG. HPLC,1H NMR, and IR analyses provided further evidence for its production. We report also that this compound inhibited the growth of the devastating rice bacterial blight pathogen Xanthomonas oryzae pv. oryzae in laboratory assays and suppressed rice bacterial blight up to 59%–64% in net-house and field experiments. Tn5 mutants defective in DAPG production (Phl–) of P. fluorescens PTB 9 were much less effective in their suppression of rice bacterial blight.Key words: biocontrol, 2,4-diacetylphloroglucinol, Pseudomonas fluorescens, rice, Xanthomonas oryzae pv. oryzae.

scholarly journals Identification of Resistance Genes Effective Against Rice Bacterial Blight Pathogen in Eastern India

Plant Disease ◽  
2001 ◽  
Vol 85 (5) ◽  
pp. 506-512 ◽  
Author(s):  
Marella Lalitha Shanti ◽  
M. L. C. George ◽  
C. M. Vera Cruz ◽  
M. A. Bernardo ◽  
R. J. Nelson ◽  
...  
Keyword(s):  
Resistance Genes ◽  
Bacterial Blight ◽  
Blight Resistance ◽  
Bacterial Blight Resistance ◽  
Single Strain ◽  
Rice Bacterial Blight ◽  
Virulence Analysis ◽  
Bacterial Blight Pathogen ◽  
Polymerase Chain ◽  
Pathogen Populations

Breeding for bacterial blight resistance in rice requires an understanding of the contemporary pathogen populations in the locations where resistance genes are to be deployed. We characterized 450 strains of Xanthomonas oryzae pv. oryzae collected from three states of India using polymerase chain reaction fingerprinting and virulence analysis. This pathogen collection was differentiated into 17 haplotypes (12 lineages at 80% similarity level). Significant differences in the distribution of haplotypes were observed among regions. Virulence analysis of the pathogen collection revealed nine pathotypes. Among the populations from three regions, the Orissa population was the most diverse, consisting of 11 out of 17 haplotypes and five out of nine pathotypes detected in the total collection. Representative pathotypes were used to evaluate seven near-isogenic lines carrying individual bacterial blight resistance genes (Xa3, Xa4, xa5, Xa7, Xa10, xa13, and Xa21) and gene pyramids. Pathogen strains compatible to individual genes were present in detectable frequencies, although no single strain could overcome all resistance genes. Gene combinations Xa4 + xa5, xa5 + Xa21, and Xa4 + xa5 + Xa21 conferred a broad spectrum of resistance to all the strains evaluated, supporting the strategy of pyramiding appropriate resistance genes.

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

2016 ◽  
Vol 29 (3) ◽  
pp. 220-230 ◽  
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.

scholarly journals Race Classification of the Bacterial Blight Pathogen, Xanthomonas oryzae pv. oryzae, by Rice NILs with Single Resistance Genes

2008 ◽  
Vol 14 (3) ◽  
pp. 165-170
Author(s):  
Jae-Eul Choi ◽  
Bo-Ra Kim ◽  
Jin-Soo Han ◽  
Hee-Kyoung Kang ◽  
Seung-Gi Hur
Keyword(s):  
Resistance Genes ◽  
Bacterial Blight ◽  
Xanthomonas Oryzae ◽  
Bacterial Blight Pathogen

Understanding the variability of rice bacterial blight pathogen, Xanthomonas oryzae pv. oryzae in Andhra Pradesh, India

2021 ◽  
Author(s):  
Arra Yugander ◽  
Md Ershad ◽  
Pitchiah P. Muthuraman ◽  
Vellaisamy Prakasam ◽  
Duraisamy Ladhalakshmi ◽  
...  
Keyword(s):  
Bacterial Blight ◽  
Andhra Pradesh ◽  
Xanthomonas Oryzae ◽  
Rice Bacterial Blight ◽  
Bacterial Blight Pathogen
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