| adaptive evolution of xa21 homologs in gramineae. | the xa21 protein has broad spectrum resistance against xanthomonas oryzae pv. oryzae. although xa21-mediated immunity is well characterized, little is known about the origin and evolutionary history of this gene in grasses. therefore, we analyzed all xa21 gene homologs in eight whole-genome sequenced rice lines, as well as in four gramineous genomes, rice, brachypodium, sorghum and maize; using arabidopsis xa21 homologs as outgroups, 17, 7, 7 and 3 xa21 homologs were detected in these four grass ... | 2011 | 22451352 |
| [expression and functional analysis of osrboh gene family in rice immune response]. | the preliminary role of respiratory burst oxidase homolog (rboh) in plant immune response is defined, but the exact function of osrboh gene in rice immune response and its expression pattern is yet unclear. in order to clarify the role of osrboh in rice immune response, we screened seven osrboh genes from the latest rice genome annotation database. the result of tissue specific expression analysis demonstrated that osrbohd was expressed only in spike and calli, and osrbohe and osrbohf were only ... | 2011 | 22393712 |
| the rsma-like gene rsma(xoo) of xanthomonas oryzae pv. oryzae regulates bacterial virulence and production of diffusible signal factor. | the plant-pathogenic prokaryote xanthomonas oryzae pv. oryzae (xoo) causes bacterial leaf blight, one of the most destructive diseases of rice. a nonpolar mutant of the rsma-like gene rsma(xoo) of the xoo chinese strain 13751 was constructed by homologous integration with a suicide plasmid. virulence tests on a host plant, namely the hybrid rice cultivar teyou 63, showed that the mutant had lost its virulence almost completely, whereas tests on a nonhost, namely castor-oil plant (ricinus communi ... | 2010 | 21355995 |
| two coiled-coil regions of xanthomonas oryzae pv. oryzae harpin differ in oligomerization and hypersensitive response induction. | hpa1(xoo) (harpin) is a type iii secreted protein of the rice blight bacterial pathogen xanthomonas oryzae pv. oryzae that elicits a hypersensitive response (hr) in nonhost tobacco. hpa1(xoo) is predicted to contain two potential coiled-coil (cc) regions, one at the n-terminus with a high probability of formation, and one at the c-terminus with a lower probability of formation. we constructed several cc-equivalent peptides by a chemosynthetic method, and investigated the structure-function of th ... | 2011 | 20532949 |
| enhanced disease resistance and hypersensitivity to bth by introduction of an nh1/osnpr1 paralog. | non-expresser of pathogenesis-related genes 1 (npr1) is the master regulator of salicylic acid-mediated systemic acquired resistance. over-expression of arabidopsis npr1 and rice nh1 (npr1 homolog1)/osnpr1 in rice results in enhanced resistance. while there are four rice npr1 paralogs in the rice genome, none have been demonstrated to function in disease resistance. to study rice npr1 paralog 3, we introduced constructs into rice and tested for effects on resistance to infection by xanthomonas o ... | 2011 | 20561248 |
| genes expressed during early stages of rice infection with the rice blast fungus magnaporthe grisea. | summary a system-wide approach was adopted to further elucidate mechanisms regulating disease outcome between rice and the fungal pathogen magnaporthe grisea. first, a cdna library was constructed from m. grisea infected rice at 48 h post-inoculation. the 5' end-sequencing of 619 randomly selected clones revealed 359 expressed sequence tags (ests) that had not previously been described. a total of 124 from 260 ests with high and moderate similarity scores, based on blastx, were organized into ca ... | 2001 | 20573024 |
| opposite functions of a rice mitogen-activated protein kinase during the process of resistance against xanthomonas oryzae. | the pathogen-induced plant defense signaling network consists of multiple components, although only some of them are characterized. most of the known components function either as activators or repressors in host-pathogen interactions. here we report that a mitogen-activated protein kinase, osmpk6, functions both as an activator and a repressor in rice resistance against xanthomonas oryzae pv. oryzae (xoo), the causal organism of bacterial blight disease. activation of osmpk6 resulted in the for ... | 2010 | 20663089 |
| metabolomic and transcriptomic analysis of the rice response to the bacterial blight pathogen xanthomonas oryzae pv. oryzae. | bacterial leaf blight (blb), caused by xanthomonas oryzae pv. oryzae (xoo), gives rise to devastating crop losses in rice. disease resistant rice cultivars are the most economical way to combat the disease. the tp309 cultivar is susceptible to infection by xoo strain pxo99. a transgenic variety, tp309_xa21, expresses the pattern recognition receptor xa21, and is resistant. pxo99 big up tri, openraxst, a strain lacking the raxst gene, is able to overcome xa21-mediated immunity. we used a single e ... | 2010 | 20676379 |
| agc kinase osoxi1 positively regulates basal resistance through suppression of ospti1a-mediated negative regulation. | ospti1a, a functional ortholog of tomato slpti1, negatively regulates both basal resistance and r-gene-mediated resistance in rice. to investigate the molecular function of ospti1a in defense responses, we searched for components interacting with ospti1a using a yeast two-hybrid system. one of the interacting proteins is a ser/thr kinase that directly phosphorylates ospti1a in vitro. this protein belongs to the agc kinase family and is highly similar to atoxi1, which is induced in response to a ... | 2010 | 20739304 |
| an h-ns-like protein involved in the negative regulation of hrp genes in xanthomonas oryzae pv. oryzae. | hrp genes encode components of a type iii secretion (t3s) system and play crucial roles in the pathogenicity of the rice pathogen xanthomonas oryzae pv. oryzae (xoo). a histone-like nucleoid-structuring (h-ns) protein binds dna and acts as a global transcriptional repressor. here, we investigated the involvement of an h-ns-like gene, named xrvb, in the expression of hrp genes in xoo. under the hrp-inducing culture condition, the expression of a key hrp regulator hrpg increased in the xrvb mutant ... | 2011 | 21410511 |
| [gene deletion and functional analysis of the eal domain protein vieaxoo in xanthomonas oryzae pv. oryzae]. | to better reveal the functions of key members involved in cyclic di-gmp signal metabolism pathways in the bacterial blight pathogen of rice xanthomonas oryzae pv. oryzae (xoo). | 2011 | 21465786 |
| crystallization and preliminary x-ray crystallographic analysis of dna gyrase gyrb subunit from xanthomonas oryzae pv. oryzae. | dna gyrase is a type ii topoisomerase that is essential for chromosome segregation and cell division owing to its ability to modify the topological forms of bacterial dna. in this study, the n-terminal fragment of the gyrb subunit of dna gyrase from xanthomonas oryzae pv. oryzae was overexpressed in escherichia coli, purified and crystallized. diffraction data were collected to 2.10 a resolution using a synchrotron-radiation source. the crystal belonged to space group i4(1), with unit-cell param ... | 2010 | 20057069 |
| characterization and genetic analysis of a light- and temperature-sensitive spotted-leaf mutant in rice (oryza sativa). | a rice spotted-leaf mutant was isolated from an ems-induced ir64 mutant bank. the mutant, designated as spl30 (spotted-leaf30), displayed normal green leaf color under shade but exhibited red-brown lesions under natural summer field conditions. initiation of the lesions was induced by light and the symptom was enhanced at 33 °c relative to 26 °c. histochemical staining did not show cell death around the red-brown lesions. chlorophyll contents in the mutant were significantly lower than those of ... | 2011 | 21605341 |
| rice wrky45 plays important roles in fungal and bacterial disease resistance. | plant 'activators', such as benzothiadiazole (bth), protect plants from various diseases by priming the plant salicylic acid (sa) signalling pathway. we have reported previously that a transcription factor identified in rice, wrky45 (oswrky45), plays a pivotal role in bth-induced disease resistance by mediating sa signalling. here, we report further functional characterization of wrky45. different plant activators vary in their action points, either downstream (bth and tiadinil) or upstream (pro ... | 2011 | 21726399 |
| using the concept of pseudo amino acid composition to predict resistance gene against xanthomonas oryzae pv. oryzae in rice: an approach from chaos games representation. | to evaluate the possibility of an unknown protein to be a resistant gene against xanthomonas oryzae pv. oryzae, a different mode of pseudo amino acid composition (pseaac) is proposed to formulate the protein samples by integrating the amino acid composition, as well as the chaos games representation (cgr) method. some numerical comparisons of triangle, quadrangle and 12-vertex polygon cgr are carried to evaluate the efficiency of using these fractal figures in classifiers. the numerical results ... | 2011 | 21703279 |
| colonization of rice leaf blades by an african strain of xanthomonas oryzae pv. oryzae depends on a new tal effector that induces the rice nodulin-3 os11n3 gene. | african strains of xanthomonas oryzae pv. oryzae contain fewer tal effectors than asian strains, and their contribution to pathogenicity is unknown. systematic mutagenesis of tal genes was used to decipher the contribution of each of the eight tal effector paralogs to pathogenicity of african x. oryzae pv. oryzae bai3. a strain mutated in talc was severely affected in the production of disease symptoms. analysis of growth in planta upon leaf-clip inoculation showed that mutant bacteria multiplie ... | 2011 | 21679014 |
| controlling rice bacterial blight in africa: needs and prospects. | rice cultivation has drastically increased in africa over the last decade. during this time, the region has also seen a rise in the incidence of rice bacterial blight caused by the pathogen xanthomonas oryzae pv. oryzae. the disease is expanding to new rice production areas and threatens food security in the region. yield losses caused by x. oryzae pv. oryzae range from 20 to 30% and can be as high as 50% in some areas. employing resistant cultivars is the most economical and effective way to co ... | 2011 | 21963588 |
| identification and fine-mapping of xa33, a novel gene for resistance to xanthomonas oryzae pv. oryzae. | abstract broadening of the genetic base for identification and transfer of genes for resistance to insect pests and diseases from wild relatives of rice is an important strategy in resistance breeding programs across the world. an accession of oryza nivara, international rice germplasm collection (irgc) accession number 105710, was identified to exhibit high level and broad-spectrum resistance to xanthomonas oryzae pv. oryzae. in order to study the genetics of resistance and to tag and map the ... | 2011 | 21970567 |
| Ortholog Alleles at Xa3/Xa26 Locus Confer Conserved Race-Specific Resistance against Xanthomonas oryzae in Rice. | The rice disease resistance (R) gene Xa3/Xa26 (having also been named Xa3 and Xa26) against Xanthomonas oryzae pv. oryzae (Xoo), which causes bacterial blight disease, belongs to a multiple gene family clustered in chromosome 11 and is from an AA genome rice cultivar (Oryza sativa L.). This family encodes leucine-rich repeat (LRR) receptor kinase-type proteins. Here, we show that the orthologs (alleles) of Xa3/Xa26, Xa3/Xa26-2, and Xa3/Xa26-3, from wild Oryza species O. officinalis (CC genome) a ... | 2011 | 21930802 |
| crystallization and preliminary x-ray crystallographic analysis of β-ketoacyl-acp synthase i (xofabb) from xanthomonas oryzae pv. oryzae. | the proteins in the fatty-acid synthesis pathway in bacteria have significant potential as targets for the development of antibacterial agents. an essential elongation step in fatty-acid synthesis is performed by β-ketoacyl-acyl carrier protein synthase i (fabb). the organism xanthomonas oryzae pv. oryzae (xoo) causes a destructive bacterial blight disease of rice. the xofabb protein from xoo was expressed, purified and crystallized for the three-dimensional structure determination that is essen ... | 2011 | 22139163 |
| effect of modified glucose catabolism on xanthan production in xanthomonas oryzae pv. oryzae. | in this study, the glucose 6-phosphate dehydrogenase gene (xoo2314) was inactivated in order to modulate the intracellular glucose 6-phosphate, and its effects on xanthan production in a wild-type strain of xanthomonas oryzae were evaluated. the intracellular glucose 6-phosphate was increased from 17.6 to 99.4 μmol g(-1) (dry cell weight) in the gene-disrupted mutant strain. the concomitant increase in the glucose 6-phosphate was accompanied by an increase in xanthan production of up to 2.23 g l ... | 2011 | 22075924 |
| characteristic expression of rice pathogenesis-related proteins in rice leaves during interactions with xanthomonas oryzae pv. oryzae. | pathogenesis-related (pr) proteins play an important role in the disease resistance response. to better understand the function of rice pr proteins, we examined the expressions of ten pr proteins in rice leaves at different developmental stages with or without the interaction between rice and xanthomonas oryzae pv. oryzae (xoo). the results showed that most of the pr proteins were expressed in rice leaves in normal growth conditions, suggesting that they play a role in rice growth. six out of te ... | 2011 | 22187088 |
| Functional analysis of the aroC gene encoding chorismate synthase from Xanthomonas oryzae pathovar oryzae. | Xanthomonas oryzae pv. oryzae causes bacterial blight in rice, and this bacterial blight has been widely found in the major rice-growing areas. We constructed a transposon mutagenesis library of X. oryzae pv. oryzae and identified a mutant strain (KXOM9) that is deficient for pigment production and virulence. Furthermore, the KXOM9 mutant was unable to grow in minimal medium lacking aromatic amino acids. Thermal asymmetric interlaced-PCR and sequence analysis of KXOM9 revealed that the transposo ... | 2011 | 22169355 |
| Small protein-mediated quorum sensing in a gram-negative bacterium. | The rice XA21 pattern recognition receptor binds a type I secreted sulfated peptide, called axY(S)22, derived from the Ax21 (activator of XA21-mediated immunity) protein. The conservation of Ax21 in all sequenced Xanthomonas spp. and closely related genera suggests that Ax21 serves a key biological function. Here we show that the predicted N-terminal sequence of Ax21 is cleaved prior to secretion outside the cell and that mature Ax21 serves as a quorum sensing (QS) factor in Xanthomonas oryzae p ... | 2011 | 22174954 |
| the colrs system of xanthomonas oryzae pv. oryzae is required for virulence and growth in iron-limiting conditions. | xanthomonas oryzae pv. oryzae, the causal agent of bacterial blight of rice, produces siderophores only under iron-limiting conditions. we screened 15 400 mtn5-induced mutants of x. oryzae pv. oryzae and isolated 27 mutants that produced siderophores even under iron-replete conditions. we found that the mtn5 insertions in 25 of these mutants were in or close to six genes. mutants with insertions in five of these genes [cols, xoo1806 (a conserved hypothetical protein), acnb, prpr and prpb] exhibi ... | 2012 | 22257308 |
| homologous expression and quantitative analysis of t3ss-dependent secretion of tap-tagged xoavrbs2 in xanthomonas oryzae pv. oryzae induced by rice leaf extract. | xanthomonas oryzae pv. oryzae (xoo) produces a putative effector, xoavrbs2. we expressed xoavrbs2 homologously in xoo with a tap-tag at the c-terminus to enable quantitative analysis of protein expression and secretion. addition of rice leaf extracts from both xoo-sensitive and xoo-resistant rice cultivars to the xoo cells induced expression of the xoavrbs2 gene at the transcriptional and translational levels, and also stimulated a remarkable amount of xoavrbs2 secretion into the medium. in a t3 ... | 2011 | 21791953 |
| molecular and pathogenic characterization of new xanthomonas oryzae pv. oryzae strains from the coastline region of fangchenggang city in china. | virulence assays and dna polymorphism analyses were used to characterize 33 xanthomonas oryzae pv. oryzae (xoo) strains collected from the coastline region of fangchenggang city in china. two new pathogenic races (fxp1 and fxp2), were determined by leaf-clipping inoculation of 12 near-isogenic international rice-bacterial blight (irbb) rice lines, each containing a single resistance gene. race fxp1 consisted of twenty-eight strains that were incompatible on irbb5 and irbb7, while race fxp2 inclu ... | 2012 | 23264131 |