Xa7
Contents
Annotated Information
Introduce
Xianhui 207, the male parent of widely-used hybrid rice Jinyou 207 (Jin 23A/Xianhui 207), was used as the recipient parent to cross with two resistance varieties, Huahui 20 carrying Xa7 and Xa21 genes and T1c-19 carrying cry1C* gene, as donor parents, to improve the bacterial blight (BB) and borer resistance of Xianhui 207. Two improved lines, designated as CY10038-1 and CY10039-1, carrying the genes of Xa7, Xa21 and cry1C*, were developed by hybridizing, backcrossing and multi-crossing with the method of molecular marker-assisted selection. Crossed with Jin 23A, two hybrids Jin 23A/CY10038-1 and Jin 23A/CY10039-1 were made. The resistances of bacterial blight, leaf folder and stem borer, the expression of CRY1C* protein and main agronomic traits including yield and grain quality were studied for the new improved lines and their derived hybrids. The results showed that two improved lines and their hybrids were resistant to seven Xoo strains, i.e., ZHE173, GD1358, PXO61, PXO99, FuJ, YN24 and HeN11. Though the CRY1C* expression in two hybrids was lower than that in the improved lines, the hybrids were highly resistant to leaf folder and stem borer in field conditions. The testing results of main agronomic traits and grain quality showed that two hybrids were similar to Jinyou 207 except for their higher yield than that of Jinyou 207. Thus, these new improved lines would have a good prospect in future hybrid rice breeding..
Function
Continuous planting of crops containing single disease resistance (R) genes imposes a strong selection for virulence in pathogen populations, often rendering the R gene ineffective. Increasing environmental temperatures may complicate R-gene-mediated disease control because high temperatures often promote disease development and reduceR gene effectiveness. Here, performance of one rice bacterial blight disease R gene was assessed in field and growth chamber studies to determine the influence of temperature on R gene effectiveness and durability. Disease severity and virulence of Xanthomonas oryzae pv. oryzae (Xoo) populations were monitored in field plots planted to rice with and without the bacterial blight R geneXa7 over 11 yr. The performance of Xa7 was determined in high- and low-temperature regimes in growth chambers. Rice with Xa7 exhibited less disease than lines without Xa7 over 11 yr, even though virulence of Xoo field populations increased. Xa7 restricted disease more effectively at high than at low temperatures. Other R genes were less effective at high temperatures.
Development and Mapping of Markers
Markers were generated that are linked to the rice bacterial blight resistance gene Xa7. Amplified restriction fragment length polymorphism (AFLP) analysis of a segregating, near-isogenic F3 population of IR24 x IRBB7 revealed one polymorphic fragment, M1, which was mapped to position 107.3 centimorgans (cM) on the Rice Genome Research Program (RGP) map. Sequence comparisons of resistant and susceptible lines near M1 were used to develop additional markers. A sequence tagged site (STS) named M2 wasmapped proximal to M1 and farther from Xa7, indicating that Xa7 lies distal to M1. On the distal side of M1, two simple sequence repeats (SSRs), M3 and M4, were mapped 0.5 and 1.8 cM, respectively, from Xa7. The pattern of recombinants was consistent with the order of M1–Xa7–M3–M4, and the map distances indicated that Xa7 is located in the region corresponding to the ends of the physically mapped Clemson University Genomics Institute (CUGI) bacterial artificial chromosome (BAC) contigs 96 and 143. A complex repeat was identified in the DNA sequence from rice (Oryza sativa L.) cultivars 93-11 and Nipponbare that matched the end of contig 96 and a previously mapped expressed sequence tag (EST) marker (C52865S). Amplification of the repeat and flanking sequences revealed the presence and absence of the repeat in IR24 and IRBB7, respectively. No recombinants were identified between Xa7 and the polymorphic repeat, which was named M5, in 277 F3 susceptible progeny of the IR24 x IRBB7 cross. Comparison of the physical and genetic maps of rice in this region indicates that Xa7 could lie within 40 kilobases (kb) of M5, a distance suitable for gene pyramiding effortsand Xa7 cloning strategies..
Expression
In the rice genome, endo-1,4-b-D-glucanases form a multiple gene family including OsGLU3 which share high sequence similarity with KOR1 (2). OsGLU3is ubiquitously expressed in various tissues with strong expression in root tip, lateral root, and crown root primodia. OsGLU3contains four exons and three introns (Fig 2B). The putative OsGLU3 was predicted to contain a transmembrane domain, a cytosolic domain, and a catalytic domain (Supplemental Fig 3A). The mutation is located in the catalytic domain, which is highly conserved among the plant KOR1 homologs (Supplemental Fig 3B). qRT–PCR showed that the OsGLU3 is highly expressed in root tissue and has relatively lower expression in the other tissues. The OsGLU3–GUS expression was observed ubiquitously in the rice plants included in leaf veins, excoemums,and roots. the OsGLU3–GFP protein may reflect the native OsGLU3.OsGLU3 localizes in the plasma member and endosomes, and the export of OsGLU3 to the PM depends on vesicle transport. Phosphate starvation could induce root elongation inOsglu3-1.The phosphate starvation-induced primary root elongation and cellulose-content increase are abolished in Osglu3-2, which suggests that phosphate starvation-induced primary root elongation depends on the activity of OsGLU3.Suggesting that a single recessive gene was responsible for the mutant phenotype. Using 1 000 F2 mutant seedlings selected from the population, the mutation was mapped to a 56-kb region between S4-24837K and S4-24893K on chromosome 4. This region contains 14 open reading frames (ORFs), including a b-1,4-endoglucanase (OsGLU3, LOC_Os04g41970)(3).
Evolution
Please input evolution information here.
In rice genome, the putative membrane-anchored endo-b-1,4-D-glucanases were encoded by three genes: OsGLU1, OsGLU2, and OsGLU3.Recently,Libertiniet al.(2004) reported that 15 endoglucanase genes were present in rice genome.that these proteins could be classified into four main clusters. One cluster contained OsGLU4, OsGLU8, OsGLU12, OsGLU13,OsGLU14 and OsGLU15. Another cluster contained OsGLU1, OsGLU2, OsGLU3, KOR and CEL3. The third cluster contained OsGLU5,OsGLU6, OsGLU7, OsGLU9, OsGLU10 and OsGLU11.OsGLU1to OsGLU10 each gene had different numbers of introns and exons. All proteins of the OsGLU family contained the EGase domain. The OsGLU1, OsGLU2 and OsGLU3 contained a predicted highly hydrophobic transmembrane motif in the N-terminal and belonged to the type II integral membrane protein anchored in the membrane. The results demonstrated thatOsGLU1, OsGLU2,OsGLU3 and OsGLU10 showed constitutive expression patterns in all the organs tested, and the OsGLU4, OsGLU5, OsGLU6, OsGLU9were abundant in roots and developing flowers of plants. The other two genes OsGLU7 and OsGLU8 showed relatively higher expression in rachis and developing flowers. These different expression patterns indicated multiple functions of these genes in different processes of plant growth and development. Specific and combinational expression of these genes may be essential for the formation or function of a given organ（2）.
Discussion
The Osglu3-1 mutant has less cellulose in its roots and is defective in root cell elongation and division. However,theshoot development ofOsglu3-1seems ormal. In rice genome, the putative membrane-anchored endo-b-1,4-D-glucanases were encoded by three genes: OsGLU1, OsGLU2, and OsGLU3. Although all of them are expressed ubiquitously in the rice plant,OsGLU1 showed high expression in shoot tissue whilstOsGLU3is highly expressed inroot tissue.This indicates that the different expression pattern of the gene members might explain the root elongation defect of Osglu3-1. Consistently with this,the mutation of OsGLU1 also resulted in a reduction in shoot cell growth(2). In our study, the exogenous glucose inhibits the primary root elongation in the WT, which might due to the osmotic stress or the glucose serving as a signal. However, it could completely restore the mutant phenotype ofOsglu3-1and partially restore the phenotype of Osglu3-2. There were two possible explanations for this phenomenon. One is that OsGLU3 might function in trimming sterol residues from nascent glucan primers. When glucose, the substrate of cellulose synthesis, is added, it leads to an increase in the glucan chain.The addition of the glucan chains together with the residual OsGLU3 enzymatic activity of the point mutation mutant could restore the phenotypic defects ofOsglu3-1. However, this explanation could not explain the partial complementation of the loss-of-function mutantOsglu3-2by the exogenous glucose. The other possibility is that OsGLU3 might hydrolyze the matrix polysaccharides or the links between matrix polysaccharides and, together with cell wall-loosening enzymes (such as expansins), create space for new synthesis cellulose.Exogenous glucose leads to an induction of cellulose synthesis,which needs more space(3).
Labs working on this gene
1.National Key Lab of Plant Genomics,People’s Republic of China. 2.Institute of Genetics and Developmental Biology, Chinese Academy of Sciences ,People’s Republic of China. 3.The State Key Laboratory of Plant Physiology and Biochemistry, College of Life Science, Zhejiang University,People’s Republic of China. 4.College of Science and Technology, Ningbo University, Ningbo, Zhejiang , China. 5.State Key Laboratory Breeding Base for Zhejiang Sustainable Pest and Disease Control, People’s Republic of China. 6.Institute of Virology and Biotechnology, Zhejiang Academy of Agricultural Sciences, Hangzhou , People’s Republic of China. 7.Laboratoire de Biologie Cellulaire, Institut National de RechercheAgronomique 8.Universite´ de Rouen, CNRS UPRESA 6307, Faculte´ des Sciences 9.Centre de Physiologie Ve´ge´tale de l’Universite ´ Paul Sabatier, U.A.
References
1. Zhang J, Xu L, Wang F, Deng M, Yi K. Modulating the root elongation by phosphate/nitrogen starvation in an OsGLU3 dependant way in rice. Plant signaling & behavior. 2012;7(9):1144-5. 2. Zhou HL, He SJ, Cao YR, Chen T, Du BX, Chu CC, et al. OsGLU1, a putative membrane-bound endo-1,4-beta-D-glucanase from rice, affects plant internode elongation. Plant molecular biology. 2006;60(1):137-51. 3. Zhang JW, Xu L, Wu YR, Chen XA, Liu Y, Zhu SH, et al. OsGLU3, a putative membrane-bound endo-1,4-beta-glucanase, is required for root cell elongation and division in rice (Oryza sativa L.). Mol Plant. 2012;5(1):176-86. 4. Fre´de´ ric Nicol1, Isabelle His, Alain Jauneau, Samantha Vernhettes, Herve´ Canut, Herman Ho¨ fte. A plasma membrane-bound putative endo-1,4-betaD-glucanase is required for normal wall assembly and cell elongation inArabidopsis. The EMBO Journal. 1998;17(19):5563-76.
Structured Information
| Gene Name |
Os08g0114200 |
|---|---|
| Description |
Similar to CEL5=CELLULASE 5 (Fragment) |
| Version |
NM_001067383.1 GI:115474502 GeneID:4344508 |
| Length |
1867 bp |
| Definition |
Oryza sativa Japonica Group Os08g0114200, complete gene. |
| Source |
Oryza sativa Japonica Group ORGANISM Oryza sativa Japonica Group
Eukaryota; Viridiplantae; Streptophyta; Embryophyta; Tracheophyta;
Spermatophyta; Magnoliophyta; Liliopsida; Poales; Poaceae; BEP
clade; Ehrhartoideae; Oryzeae; Oryza.
|
| Chromosome | |
| Location |
Chromosome 8:762215..764081 |
| Sequence Coding Region |
762288..762572,762658..763944 |
| Expression | |
| Genome Context |
<gbrowseImage1> name=NC_008401:762215..764081 source=RiceChromosome08 preset=GeneLocation </gbrowseImage1> |
| Gene Structure |
<gbrowseImage2> name=NC_008401:762215..764081 source=RiceChromosome08 preset=GeneLocation </gbrowseImage2> |
| Coding Sequence |
<cdnaseq>atgtgcagttggtcactctcgagccacactctcacttcgccggtgaggcaggcagcaatggagccaaagagcagcagctgcggcggcgccggcattcggctgcggctgctggtcgtgctccacctgctgctcttagttccgagctcggccatggcgttcaactacgccgacgcgctcgccaagtccatcatcttcttcgagggccagcgctccggcaagctcccgcccggcaaccgcatgccgtggcgcgccgactccggcctcaccgacggcgcccagtacaatgtggatttggtgggcgggtactacgacgccggcgacaacgtcaagttcggcctgcccatggcgttctcgacgacgatgctggcgtggagcgtgctcgacttcggcaagttcatgggcgccgagctgcccaacgcccgcgccgccgtgcgctggggcgccgactacctcctcaaggccgccaccgccacgcccggcgcgctctacgtccaggtcgccgaccccaaccaggaccaccgctgctgggagcgccccgaggacatggacacaccccgcagcgtctaccgcgtcaccgccgacaagccgggttccgacgtcgccggcgagacggccgccgcgctcgccgcgtcgtccatggtgttccgccgcgccgacccggcctactccgcgcgcctcctccacgccgcgacgcaggtgttcgacttcgccgaccggcaccgcgggtcgtacagcgactcgctggcgtcgtcggtgtgcccgttctactgctcctactcgggctaccacgacgagctcctgtggggggcgtcgtggctgcaccgcgcgtcgaggaacgcgtcgttcatgtcgtacgtggaggcgaacgggatgcagctcggcgccggggacgacgactactccttcagctgggacgacaagcgggtgggcaccaaggtgctcctcgccaagggcttcctccgcaaccgcctccatggcctcgagctctacaaggcgcactccgacagctacatctgctcgctggtgcccggcacggcgagcttccagtcgcggtacacccccggcggcctcctgtacagggaaggctccagcaacatgcagtacgtgacgacggcgacgttcctgatgctggcgtacgccaagtacctccggtcgagcggcgccaccgcgtcgtgcggcgacggcggcggcggagcgaggggggaggtgtcggcggcggagctggtggcggtggcgaagcggcaggtggactacatcctggggaagaacccggcggggatgtcgtacatggtggggttcgggtgcaggtacccgaggcgggcgcaccaccgcggcgcgtccatgccgtcggtgcgcgcccacccggggcggatctcctgcgacgccggcttcggctacctccactccggcgagcccaacccgaacgtgctcgtcggcgccgtcgtcggcgggccggacagccgcgacgcctttgccgacgaccgcggcaacttcgcgcagtcggagccggccacctacatcaacgcgccgctcgtcggcgcgctcgcctacttcgccggaaccaccaagtag</cdnaseq> |
| Protein Sequence |
<aaseq>MCSWSLSSHTLTSPVRQAAMEPKSSSCGGAGIRLRLLVVLHLLL LVPSSAMAFNYADALAKSIIFFEGQRSGKLPPGNRMPWRADSGLTDGAQYNVDLVGGY YDAGDNVKFGLPMAFSTTMLAWSVLDFGKFMGAELPNARAAVRWGADYLLKAATATPG ALYVQVADPNQDHRCWERPEDMDTPRSVYRVTADKPGSDVAGETAAALAASSMVFRRA DPAYSARLLHAATQVFDFADRHRGSYSDSLASSVCPFYCSYSGYHDELLWGASWLHRA SRNASFMSYVEANGMQLGAGDDDYSFSWDDKRVGTKVLLAKGFLRNRLHGLELYKAHS DSYICSLVPGTASFQSRYTPGGLLYREGSSNMQYVTTATFLMLAYAKYLRSSGATASC GDGGGGARGEVSAAELVAVAKRQVDYILGKNPAGMSYMVGFGCRYPRRAHHRGASMPS VRAHPGRISCDAGFGYLHSGEPNPNVLVGAVVGGPDSRDAFADDRGNFAQSEPATYIN APLVGALAYFAGTTK</aaseq> |
| Gene Sequence |
<dnaseqindica>74..358#444..1730#agcaaattgatatactactccagcaccggccaaattaactaacttaacggccactgcttttcacactatattaatgtgcagttggtcactctcgagccacactctcacttcgccggtgaggcaggcagcaatggagccaaagagcagcagctgcggcggcgccggcattcggctgcggctgctggtcgtgctccacctgctgctcttagttccgagctcggccatggcgttcaactacgccgacgcgctcgccaagtccatcatcttcttcgagggccagcgctccggcaagctcccgcccggcaaccgcatgccgtggcgcgccgactccggcctcaccgacggcgcccagtacaatgtacgtacgccgcctctctctctttccctttcttccttgtctccggcgaggaggagtttgtgattccggcgtgtttgtgtttcaggtggatttggtgggcgggtactacgacgccggcgacaacgtcaagttcggcctgcccatggcgttctcgacgacgatgctggcgtggagcgtgctcgacttcggcaagttcatgggcgccgagctgcccaacgcccgcgccgccgtgcgctggggcgccgactacctcctcaaggccgccaccgccacgcccggcgcgctctacgtccaggtcgccgaccccaaccaggaccaccgctgctgggagcgccccgaggacatggacacaccccgcagcgtctaccgcgtcaccgccgacaagccgggttccgacgtcgccggcgagacggccgccgcgctcgccgcgtcgtccatggtgttccgccgcgccgacccggcctactccgcgcgcctcctccacgccgcgacgcaggtgttcgacttcgccgaccggcaccgcgggtcgtacagcgactcgctggcgtcgtcggtgtgcccgttctactgctcctactcgggctaccacgacgagctcctgtggggggcgtcgtggctgcaccgcgcgtcgaggaacgcgtcgttcatgtcgtacgtggaggcgaacgggatgcagctcggcgccggggacgacgactactccttcagctgggacgacaagcgggtgggcaccaaggtgctcctcgccaagggcttcctccgcaaccgcctccatggcctcgagctctacaaggcgcactccgacagctacatctgctcgctggtgcccggcacggcgagcttccagtcgcggtacacccccggcggcctcctgtacagggaaggctccagcaacatgcagtacgtgacgacggcgacgttcctgatgctggcgtacgccaagtacctccggtcgagcggcgccaccgcgtcgtgcggcgacggcggcggcggagcgaggggggaggtgtcggcggcggagctggtggcggtggcgaagcggcaggtggactacatcctggggaagaacccggcggggatgtcgtacatggtggggttcgggtgcaggtacccgaggcgggcgcaccaccgcggcgcgtccatgccgtcggtgcgcgcccacccggggcggatctcctgcgacgccggcttcggctacctccactccggcgagcccaacccgaacgtgctcgtcggcgccgtcgtcggcgggccggacagccgcgacgcctttgccgacgaccgcggcaacttcgcgcagtcggagccggccacctacatcaacgcgccgctcgtcggcgcgctcgcctacttcgccggaaccaccaagtagccattagtgagagtgtgagtgacgtggcagtgtgggagcgcgaggccagtgagatgagctcccccgccacgctgtatcgttcgttgactttgtcgtgtattcgacgcaacaaacagtatttgcacggagtacgtacg</dnaseqindica> |
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