Evolution of the Rice Xa21 Disease Resistance Gene Family

Song, Wenlei; Pi, Liya; Wang, Guoliang; Gardner, John; Holsten, Tom; Ronald, Pamela C.

doi:10.2307/3870381

Cited by 85 publications

(146 citation statements)

References 8 publications

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“…NBLets are not exclusive to the non-TIR NB-LRR class of R genes; they have been noted in the TIR class as well (Graham et al 2002). Xa21, a member of a third class of R genes, has been shown to have a highly conserved 59 domain that is important for mediating recombination between genetically linked paralogs (Song et al 1997).…”

Section: Discussionmentioning

confidence: 99%

The Fractionated Orthology of Bs2 and Rx/Gpa2 Supports Shared Synteny of Disease Resistance in the Solanaceae

et al. 2009

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Comparative genomics provides a powerful tool for the identification of genes that encode traits shared between crop plants and model organisms. Pathogen resistance conferred by plant R genes of the nucleotide-binding-leucine-rich-repeat (NB-LRR) class is one such trait with great agricultural importance that occupies a critical position in understanding fundamental processes of pathogen detection and coevolution. The proposed rapid rearrangement of R genes in genome evolution would make comparative approaches tenuous. Here, we test the hypothesis that orthology is predictive of R-gene genomic location in the Solanaceae using the pepper R gene Bs2. Homologs of Bs2 were compared in terms of sequence and gene and protein architecture. Comparative mapping demonstrated that Bs2 shared macrosynteny with R genes that best fit criteria determined to be its orthologs. Analysis of the genomic sequence encompassing solanaceous R genes revealed the magnitude of transposon insertions and local duplications that resulted in the expansion of the Bs2 intron to 27 kb and the frequently detected duplications of the 59-end of R genes. However, these duplications did not impact protein expression or function in transient assays. Taken together, our results support a conservation of synteny for NB-LRR genes and further show that their distribution in the genome has been consistent with global rearrangements.

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Section: Discussionmentioning

confidence: 99%

The Fractionated Orthology of Bs2 and Rx/Gpa2 Supports Shared Synteny of Disease Resistance in the Solanaceae

et al. 2009

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“…Pulsed-®eld gel electrophoresis and genetic analysis demonstrated that most of members of the Xa21 gene family are located in a 230-kb genomic region on chromosome 11 (Ronald et al 1992;Williams et al 1996). We have cloned and sequenced seven Xa21 family members designated A1, A2, B (Xa21), C, D, E, and F (Song et al , 1997Wang et al 1995). Based on sequence comparisons, two subfamilies were identi®ed: the Xa21 subfamily consisting of Xa21, D and F, and the A2 subfamily consisting of A1, A2, C and E. Within a subfamily, members show 95±98% identity.…”

Section: Introductionmentioning

confidence: 99%

“…Genomic Southern analysis revealed that there are at least 100 copies of Tnt1 in the tobacco genome. Other identi®ed plant retrotransposons include: Bs1, Stonor, Hopscotch, and Magellan in maize (Johns et al 1985;Varagona et al 1992;White et al 1994;Purugganan and Wessler 1994); Tto1 and Tto2 in tobacco (Hirochika 1993); and Tos10, Tos17, Tos19, and Retro®t in rice (Hirochika et al 1996;Song et al 1997).…”

Section: Introductionmentioning

confidence: 99%

“…Based on sequence comparisons, two subfamilies were identi®ed: the Xa21 subfamily consisting of Xa21, D and F, and the A2 subfamily consisting of A1, A2, C and E. Within a subfamily, members show 95±98% identity. Two transposon-like elements were identi®ed in the presumed coding regions of the Xa21 family members D and E, creating ORFs that encode truncated proteins (Song et al 1997). In addition, Wanderer, a MITE element, was found in an Xa21-linked noncoding region (Bureau et al 1996).…”

Section: Introductionmentioning

confidence: 99%

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Identification and characterization of 14 transposon-like elements in the noncoding regions of members of the Xa21 family of disease resistance genes in rice

Song

Bureau

et al. 1998

Mol Gen Genet

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“…Plant transformation also offers the immediate possibility of introducing simultaneously several different R gene alleles that are effective against a single pathogen species. In theory, this should slow the process of microbe evolution, because the various R genes should be overcome only if all the corresponding avirulence (Avr) gene products mutate simultaneously within a single pathogen isolate [3][4][5][6][7][8][9][10][11][12][13] Pennisetum glaucum (L.) R. Br. is the most widely grown millet has had an important impact on small farmer welfare in India.…”

Section: Introductionmentioning

confidence: 99%

Chitosan and ß-amino butyric acid up-regulates transcripts of resistance gene analog RGPM213 in pearl millet to infection by downy mildew pathogen

2016

J App Biol Biotech

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Plants are hosts to a diverse group of pathogens belonging to different kingdoms of life. In absence of active immune system, plants have evolved several layers of defense to combat individual pathogen strain and evolving pathogen populations. Management of various plant pathogen infections necessitates the use of multiple resistance (R) genes, which requires efficient and accurate practices for identification, isolation and characterization of R genes. This knowledge helps to probe R gene(s) in a host plant and sort out their functional redundancy and specificity. Pearl millet [Pennisetum glaucum (L.) R. Br.] is highly nutritive, summer-annual forage crop, drought tolerant cereal, staple food crop of the semi-arid tropics but is highly susceptible to the downy mildew disease caused by oomycetous Sclerospora graminicola (Sacc.) schroet. Earlier studies have identified several resistance gene analogues (RGAs) in pearl millet which may be involved in resistance against downy mildew. Of these, a clone RGPM213 was shown to encode resistant protein having serine threonine kinase domain and its transcript was upregulated following S. graminicola infection and β-amino butyric acid an abiotic inducer treatment. Here we have shown the accumulation of transcripts of RGPM 213 in pearl millet during treatment with Chitosan, a chitin derivative, a known inducer of plant defense which is completely safe, characterized by unique properties, like bioactivity and biocompatibility.

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Evolution of the Rice Xa21 Disease Resistance Gene Family

Cited by 85 publications

References 8 publications

The Fractionated Orthology of Bs2 and Rx/Gpa2 Supports Shared Synteny of Disease Resistance in the Solanaceae

The Fractionated Orthology of Bs2 and Rx/Gpa2 Supports Shared Synteny of Disease Resistance in the Solanaceae

Identification and characterization of 14 transposon-like elements in the noncoding regions of members of the Xa21 family of disease resistance genes in rice

Chitosan and ß-amino butyric acid up-regulates transcripts of resistance gene analog RGPM213 in pearl millet to infection by downy mildew pathogen

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