| 80 matches found in 35 documents. Search time: 0.045 seconds. |
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Score: 5.00 |
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| Title: Loss-of-function mutations in the rice homeobox gene OSH15 affect the architecture of internodes resulting in dwarf plants .
| | Author: Sato Y Sentoku N Miura Y Hirochika H Kitano H Matsuoka M | | Citation: V : 18 ( 4 ) P : 992-1002 Year: 1999 Type: ARTICLE | | Literature: oryza Field: abstract Doc ID: pub10022841 Accession (PMID): 10022841 | | Abstract: The rice homeobox gene OSH15 ( Oryza sativa homeobox ) is a member of the knotted1-type homeobox gene family .
We report here on the identification and characterization of a loss-of-function mutation in OSH15 from a library of retrotransposon-tagged lines of rice .
Based on the phenotype and map position , we have identified three independent deletion alleles of the locus among conventional morphological mutants .
All of these recessive mutations , which are considered to be null alleles , exhibit defects in internode elongation .
Introduction of a 14 kbp genomic DNA fragment that includes all exons , introns and 5- and 3- flanking sequences of OSH15 complemented the defects in internode elongation , confirming that they were caused by the loss-of-function of OSH15 .
Internodes of the mutants had abnormal-shaped epidermal and hypodermal cells and showed an unusual arrangement of small vascular bundles .
These mutations demonstrate a role for OSH15 in the development of rice internodes .
This is the first evidence that the knotted1-type homeobox genes have roles other than shoot apical meristem formation and/or maintenance in plant development . | Matching Sentences:
[ Sen. 5, subscore: 2.00 ]: The rice homeobox gene OSH15 ( Oryza sativa homeobox ) is a member of the knotted1-type homeobox gene family . We report here on the identification and characterization of a loss-of-function mutation in OSH15 from a library of retrotransposon-tagged lines of rice . Based on the phenotype and map position , we have identified three independent deletion alleles of the locus among conventional morphological mutants . All of these recessive mutations , which are considered to be null alleles , exhibit defects in internode elongation . Introduction of a 14 kbp genomic DNA fragment that includes all exons , introns and 5- and 3- flanking sequences of OSH15 complemented the defects in internode elongation , confirming that they were caused by the loss-of-function of OSH15 . Internodes of the mutants had abnormal-shaped epidermal and hypodermal cells and showed an unusual arrangement of small vascular bundles . These mutations demonstrate a role for OSH15 in the development of rice internodes . This is the first evidence that the knotted1-type homeobox genes have roles other than shoot apical meristem formation and/or maintenance in plant development .
[ Sen. 1, subscore: 1.00 ]: The rice homeobox gene OSH15 ( Oryza sativa homeobox ) is a member of the knotted1-type homeobox gene family . We report here on the identification and characterization of a loss-of-function mutation in OSH15 from a library of retrotransposon-tagged lines of rice . Based on the phenotype and map position , we have identified three independent deletion alleles of the locus among conventional morphological mutants . All of these recessive mutations , which are considered to be null alleles , exhibit defects in internode elongation . Introduction of a 14 kbp genomic DNA fragment that includes all exons , introns and 5- and 3- flanking sequences of OSH15 complemented the defects in internode elongation , confirming that they were caused by the loss-of-function of OSH15 .
[ Sen. 2, subscore: 1.00 ]: The rice homeobox gene OSH15 ( Oryza sativa homeobox ) is a member of the knotted1-type homeobox gene family . We report here on the identification and characterization of a loss-of-function mutation in OSH15 from a library of retrotransposon-tagged lines of rice . Based on the phenotype and map position , we have identified three independent deletion alleles of the locus among conventional morphological mutants . All of these recessive mutations , which are considered to be null alleles , exhibit defects in internode elongation . Introduction of a 14 kbp genomic DNA fragment that includes all exons , introns and 5- and 3- flanking sequences of OSH15 complemented the defects in internode elongation , confirming that they were caused by the loss-of-function of OSH15 . Internodes of the mutants had abnormal-shaped epidermal and hypodermal cells and showed an unusual arrangement of small vascular bundles .
[ Sen. 7, subscore: 1.00 ]: Based on the phenotype and map position , we have identified three independent deletion alleles of the locus among conventional morphological mutants . All of these recessive mutations , which are considered to be null alleles , exhibit defects in internode elongation . Introduction of a 14 kbp genomic DNA fragment that includes all exons , introns and 5- and 3- flanking sequences of OSH15 complemented the defects in internode elongation , confirming that they were caused by the loss-of-function of OSH15 . Internodes of the mutants had abnormal-shaped epidermal and hypodermal cells and showed an unusual arrangement of small vascular bundles . These mutations demonstrate a role for OSH15 in the development of rice internodes . This is the first evidence that the knotted1-type homeobox genes have roles other than shoot apical meristem formation and/or maintenance in plant development .
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Score: 3.00 |
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| Title: Characterization of the KNOX class homeobox genes Oskn2 and Oskn3 identified in a collection of cDNA libraries covering the early stages of rice embryogenesis .
| | Author: Postma-Haarsma AD Verwoert II Stronk OP Koster J Lamers GE Hoge JH Meijer AH .
| | Citation: V : 39 ( 2 ) P : 257-71 Year: 1999 Type: ARTICLE | | Literature: oryza Field: abstract Doc ID: pub10080693 Accession (PMID): 10080693 | | Abstract: For identification of genes involved in embryogenesis in the model cereal rice , we have constructed a collection of cDNA libraries of well-defined stages of embryo development before , during and after organ differentiation .
Here , we focus on the possible role of KNOX ( maize Knotted1-like ) class homeobox genes in regulation of rice embryogenesis .
Three types of KNOX clones were identified in libraries of early zygotic embryos .
Two of these , Oskn2 and Oskn3 , encode newly described KNOX genes , whereas the third ( Oskn1 ) corresponds to the previously described OSH1 gene .
In situ hybridizations showed that during the early stages of embryo development , all three KNOX genes are expressed in the region where the shoot apical meristem ( SAM ) is organizing , suggesting that these genes are involved in regulating SAM formation .
Whereas OSH1 was previously proposed to function also in SAM maintenance , Oskn3 may be involved in patterning organ positions , as its expression was found to mark the boundaries of different embryonic organs following SAM formation .
The expression pattern of Oskn2 suggested an additional role in scutellum and epiblast development .
Transgenic expression of Oskn2 and Oskn3 in tobacco further supported their involvement in cell fate determination , like previously reported for Knotted1 and OSH1 ectopic expression .
Whereas Oskn3 transformants showed the most pronounced phenotypic effects during vegetative development , Oskn2 transformants showed relatively mild alterations in the vegetative phase but a more severely affected flower morphology .
The observation that the KNOX genes produce similar though distinct phenotypic reponses in tobacco , indicates that their gene products act on overlapping but different sets of target genes , or that cell-type specific factors determine their precise action . | Matching Sentences:
[ Sen. 4, subscore: 1.00 ]: For identification of genes involved in embryogenesis in the model cereal rice , we have constructed a collection of cDNA libraries of well-defined stages of embryo development before , during and after organ differentiation . Here , we focus on the possible role of KNOX ( maize Knotted1-like ) class homeobox genes in regulation of rice embryogenesis . Three types of KNOX clones were identified in libraries of early zygotic embryos . Two of these , Oskn2 and Oskn3 , encode newly described KNOX genes , whereas the third ( Oskn1 ) corresponds to the previously described OSH1 gene . In situ hybridizations showed that during the early stages of embryo development , all three KNOX genes are expressed in the region where the shoot apical meristem ( SAM ) is organizing , suggesting that these genes are involved in regulating SAM formation . Whereas OSH1 was previously proposed to function also in SAM maintenance , Oskn3 may be involved in patterning organ positions , as its expression was found to mark the boundaries of different embryonic organs following SAM formation . The expression pattern of Oskn2 suggested an additional role in scutellum and epiblast development . Transgenic expression of Oskn2 and Oskn3 in tobacco further supported their involvement in cell fate determination , like previously reported for Knotted1 and OSH1 ectopic expression .
[ Sen. 6, subscore: 1.00 ]: Here , we focus on the possible role of KNOX ( maize Knotted1-like ) class homeobox genes in regulation of rice embryogenesis . Three types of KNOX clones were identified in libraries of early zygotic embryos . Two of these , Oskn2 and Oskn3 , encode newly described KNOX genes , whereas the third ( Oskn1 ) corresponds to the previously described OSH1 gene . In situ hybridizations showed that during the early stages of embryo development , all three KNOX genes are expressed in the region where the shoot apical meristem ( SAM ) is organizing , suggesting that these genes are involved in regulating SAM formation . Whereas OSH1 was previously proposed to function also in SAM maintenance , Oskn3 may be involved in patterning organ positions , as its expression was found to mark the boundaries of different embryonic organs following SAM formation . The expression pattern of Oskn2 suggested an additional role in scutellum and epiblast development . Transgenic expression of Oskn2 and Oskn3 in tobacco further supported their involvement in cell fate determination , like previously reported for Knotted1 and OSH1 ectopic expression . Whereas Oskn3 transformants showed the most pronounced phenotypic effects during vegetative development , Oskn2 transformants showed relatively mild alterations in the vegetative phase but a more severely affected flower morphology . The observation that the KNOX genes produce similar though distinct phenotypic reponses in tobacco , indicates that their gene products act on overlapping but different sets of target genes , or that cell-type specific factors determine their precise action .
[ Sen. 8, subscore: 1.00 ]: Two of these , Oskn2 and Oskn3 , encode newly described KNOX genes , whereas the third ( Oskn1 ) corresponds to the previously described OSH1 gene . In situ hybridizations showed that during the early stages of embryo development , all three KNOX genes are expressed in the region where the shoot apical meristem ( SAM ) is organizing , suggesting that these genes are involved in regulating SAM formation . Whereas OSH1 was previously proposed to function also in SAM maintenance , Oskn3 may be involved in patterning organ positions , as its expression was found to mark the boundaries of different embryonic organs following SAM formation . The expression pattern of Oskn2 suggested an additional role in scutellum and epiblast development . Transgenic expression of Oskn2 and Oskn3 in tobacco further supported their involvement in cell fate determination , like previously reported for Knotted1 and OSH1 ectopic expression . Whereas Oskn3 transformants showed the most pronounced phenotypic effects during vegetative development , Oskn2 transformants showed relatively mild alterations in the vegetative phase but a more severely affected flower morphology . The observation that the KNOX genes produce similar though distinct phenotypic reponses in tobacco , indicates that their gene products act on overlapping but different sets of target genes , or that cell-type specific factors determine their precise action .
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Score: 5.00 |
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| Title: Initiation of shoot apical meristem in rice : characterization of four SHOOTLESS genes .
| | Author: Satoh N Hong SK Nishimura A Matsuoka M Kitano H Nagato Y | | Citation: V : 126 ( 16 ) P : 3629-36 Year: 1999 Type: ARTICLE | | Literature: oryza Field: abstract Doc ID: pub10409508 Accession (PMID): 10409508 | | Abstract: The regulatory mechanism of shoot apical meristem ( SAM ) initiation is an important subject in developmental plant biology .
We characterized nine recessive mutations derived from four independent loci ( SHL1-SHL4 ) causing the deletion of the SAM .
Radicles were produced in these mutant embryos .
Concomitant with the loss of SAM , two embryo-specific organs , coleoptile and epiblast , were lost , but the scutellum was formed normally .
Therefore , differentiation of radicle and scutellum is regulated independently of SAM , but that of coleoptile and epiblast may depend on SAM .
Regeneration experiments using adventitious shoots from the scutellum-derived calli showed that no adventitious shoots were regenerated in any shl mutant .
However , small adventitious leaves were observed in both mutant and wild-type calli , but they soon became necrotic and showed no extensive growth .
Thus , leaf primordia can initiate in the absence of SAM , but their extensive growth requires the SAM .
An in situ hybridization experiment using a rice homeobox gene , OSH1 , as a probe revealed that shl1 and shl2 modified the expression domain of OSH1 , but normal expression of OSH1 was observed in shl3 and shl4 embryos .
Accordingly , SHL1 and SHL2 function upstream of OSH1 , and SHL3 and SHL4 downstream or independently of OSH1 .
These shl mutants are useful for elucidating the genetic program driving SAM initiation and for unraveling the interrelationships among various organs in grass embryos . | Matching Sentences:
[ Sen. 9, subscore: 3.00 ]: Therefore , differentiation of radicle and scutellum is regulated independently of SAM , but that of coleoptile and epiblast may depend on SAM . Regeneration experiments using adventitious shoots from the scutellum-derived calli showed that no adventitious shoots were regenerated in any shl mutant . However , small adventitious leaves were observed in both mutant and wild-type calli , but they soon became necrotic and showed no extensive growth . Thus , leaf primordia can initiate in the absence of SAM , but their extensive growth requires the SAM . An in situ hybridization experiment using a rice homeobox gene , OSH1 , as a probe revealed that shl1 and shl2 modified the expression domain of OSH1 , but normal expression of OSH1 was observed in shl3 and shl4 embryos . Accordingly , SHL1 and SHL2 function upstream of OSH1 , and SHL3 and SHL4 downstream or independently of OSH1 . These shl mutants are useful for elucidating the genetic program driving SAM initiation and for unraveling the interrelationships among various organs in grass embryos .
[ Sen. 10, subscore: 2.00 ]: Regeneration experiments using adventitious shoots from the scutellum-derived calli showed that no adventitious shoots were regenerated in any shl mutant . However , small adventitious leaves were observed in both mutant and wild-type calli , but they soon became necrotic and showed no extensive growth . Thus , leaf primordia can initiate in the absence of SAM , but their extensive growth requires the SAM . An in situ hybridization experiment using a rice homeobox gene , OSH1 , as a probe revealed that shl1 and shl2 modified the expression domain of OSH1 , but normal expression of OSH1 was observed in shl3 and shl4 embryos . Accordingly , SHL1 and SHL2 function upstream of OSH1 , and SHL3 and SHL4 downstream or independently of OSH1 . These shl mutants are useful for elucidating the genetic program driving SAM initiation and for unraveling the interrelationships among various organs in grass embryos .
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Score: 1.00 |
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| Title: Shoot organization genes regulate shoot apical meristem organization and the pattern of leaf primordium initiation in rice .
| | Author: Itoh JI Kitano H Matsuoka M Nagato Y | | Citation: V : 12 ( 11 ) P : 2161-74 Year: 2000 Type: ARTICLE | | Literature: oryza Field: abstract Doc ID: pub11090216 Accession (PMID): 11090216 | | Abstract: The mechanism regulating the pattern of leaf initiation was analyzed by using shoot organization ( sho ) mutants derived from three loci ( SHO1 , SHO2 , and SHO3 ) .
In the early vegetative phase , sho mutants show an increased rate of leaf production with random phyllotaxy .
The resulting leaves are malformed , threadlike , or short and narrow .
Their shoot apical meristems are relatively low and wide , that is , flat shaped , although their shape and size are highly variable among plants of the same genotype .
Statistical analysis reveals that the shape of the shoot meristem rather than its size is closely correlated with the variations of plastochron and phyllotaxy .
Rapid and random leaf production in sho mutants is correlated with the frequent and disorganized cell divisions in the shoot meristem and with a reduction of expression domain of a rice homeobox gene , OSH1 .
These changes in the organization and behavior of the shoot apical meristems suggest that sho mutants have fewer indeterminate cells and more determinate cells than wild type , with many cells acting as leaf founder cells .
Thus , the SHO genes have an important role in maintaining the proper organization of the shoot apical meristem , which is essential for the normal initiation pattern of leaf primordia . | Matching Sentences:
[ Sen. 6, subscore: 1.00 ]: In the early vegetative phase , sho mutants show an increased rate of leaf production with random phyllotaxy . The resulting leaves are malformed , threadlike , or short and narrow . Their shoot apical meristems are relatively low and wide , that is , flat shaped , although their shape and size are highly variable among plants of the same genotype . Statistical analysis reveals that the shape of the shoot meristem rather than its size is closely correlated with the variations of plastochron and phyllotaxy . Rapid and random leaf production in sho mutants is correlated with the frequent and disorganized cell divisions in the shoot meristem and with a reduction of expression domain of a rice homeobox gene , OSH1 . These changes in the organization and behavior of the shoot apical meristems suggest that sho mutants have fewer indeterminate cells and more determinate cells than wild type , with many cells acting as leaf founder cells . Thus , the SHO genes have an important role in maintaining the proper organization of the shoot apical meristem , which is essential for the normal initiation pattern of leaf primordia .
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Score: 1.00 |
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| Title: The LAX1 and FRIZZY PANICLE 2 genes determine the inflorescence architecture of rice by controlling rachis-branch and spikelet development .
| | Author: Komatsu M Maekawa M Shimamoto K Kyozuka J | | Citation: V : 231 ( 2 ) P : 364-73 Year: 2001 Type: ARTICLE | | Literature: oryza Field: abstract Doc ID: pub11237465 Accession (PMID): 11237465 | | Abstract: We have analyzed two mutants that exhibit altered panicle architecture in rice ( Oryza sativa L ) .
In lax1-2 , which is a new and stronger allele of the previously reported lax mutant , initiation and/or maintenance of rachis-branches , lateral spikelets , and terminal spikelets was severely prevented .
In situ hybridization analysis using OSH1 , a rice knotted1 ( kn1 ) ortholog , confirmed the absence of lateral meristems in lax1-2 panicles .
These defects indicate that the LAX1 gene is required for the initiation/maintenance of axillary meristems in the rice panicle .
In addition to its role in forming lateral meristems , the wild-type LAX1 gene acts as a floral meristem identity gene which specifies the terminal spikelet meristem .
A comparison of the defects in lax1-1 and lax1-2 plants suggested that the sensitivities to reduced LAX1 activity were not uniform among different types of meristems .
In the fzp2 mutant panicle , the basic branching pattern of the panicle was indistinguishable from that of the wild type ; however , specification of both terminal and lateral spikelet meristems was blocked , and sequential rounds of branching occurred at the point where the spikelet meristems are initiated in the wild-type panicle .
This resulted in the generation of a panicle composed of excessive ramification of rachis-branches .
The lax1-1 fzp2 double mutants exhibited a novel , basically additive , phenotype , which suggests that LAX1 and FZP2 function in genetically independent pathways . | Matching Sentences:
[ Sen. 3, subscore: 1.00 ]: We have analyzed two mutants that exhibit altered panicle architecture in rice ( Oryza sativa L ) . In lax1-2 , which is a new and stronger allele of the previously reported lax mutant , initiation and/or maintenance of rachis-branches , lateral spikelets , and terminal spikelets was severely prevented . In situ hybridization analysis using OSH1 , a rice knotted1 ( kn1 ) ortholog , confirmed the absence of lateral meristems in lax1-2 panicles . These defects indicate that the LAX1 gene is required for the initiation/maintenance of axillary meristems in the rice panicle . In addition to its role in forming lateral meristems , the wild-type LAX1 gene acts as a floral meristem identity gene which specifies the terminal spikelet meristem . A comparison of the defects in lax1-1 and lax1-2 plants suggested that the sensitivities to reduced LAX1 activity were not uniform among different types of meristems . In the fzp2 mutant panicle , the basic branching pattern of the panicle was indistinguishable from that of the wild type ; however , specification of both terminal and lateral spikelet meristems was blocked , and sequential rounds of branching occurred at the point where the spikelet meristems are initiated in the wild-type panicle .
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