| 16 matches found in 9 documents. Search time: 0.046 seconds. |
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Score: 7.00 |
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| Title: A novel cytochrome P450 is implicated in brassinosteroid biosynthesis via the characterization of a rice dwarf mutant , dwarf11 , with reduced seed length .
| | Author: Tanabe S Ashikari M Fujioka S Takatsuto S Yoshida S Yano M Yoshimura A Kitano H Matsuoka M Fujisawa Y Kato H Iwasaki Y | | Journal: Plant Cell Citation: V : 17 ( 3 ) P : 776-90 Year: 2005 Type: ARTICLE | | Literature: oryza Field: abstract Doc ID: pub15705958 Accession (PMID): 15705958 | | Abstract: We have characterized a rice ( Oryza sativa ) dwarf mutant , dwarf11 ( d11 ) , that bears seeds of reduced length .
To understand the mechanism by which seed length is regulated , the D11 gene was isolated by a map-based cloning method .
The gene was found to encode a novel cytochrome P450 ( CYP724B1 ) , which showed homology to enzymes involved in brassinosteroid ( BR ) biosynthesis .
The dwarf phenotype of d11 mutants was restored by the application of the brassinolide ( BL ) .
Compared with wild-type plants , the aberrant D11 mRNA accumulated at higher levels in d11 mutants and was dramatically reduced by treatment with BL , implying that the gene is feedback-regulated by BL .
Precise determination of the defective step ( s ) in BR synthesis in d11 mutants proved intractable because of it issue specificity and the complex control of BR accumulation in plants .
However , 6-deoxotyphasterol ( 6-DeoxoTY ) and typhasterol ( TY ) , but not any upstream intermediates before these compounds , effectively restored BR response in d11 mutants in a lamina joint bending assay .
Multiple lines of evidence together suggest that the D11/CYP724B1 gene plays a role in BR synthesis and may be involved in the supply of 6-DeoxoTY and TY in the BR biosynthesis network in rice . | | Supplemental links/files: reference in endnote online text related articles pubmed citation | |
Score: 3.00 |
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| Title: Categories and inheritance of resistance to Nilaparvata lugens ( Hemiptera : Delphacidae ) in mutants of indica rice IR64 .
| | Author: Sangha JS Chen YH Palchamy K Jahn GC Maheswaran M Adalla CB Leung H | | Journal: J Econ Entomol Citation: V : 101 P : 575-83 Year: 2008 Type: In-Process | | Literature: oryza Field: abstract Doc ID: pub18459427 Accession (PMID): 18459427 | | Abstract: Varietal mutants can be useful for developing durable resistance , understanding categories of resistance , and identifying candidate genes involved in defense responses .
We used mutants of rice IR64 to isolate new sources of resistance to the planthopper Nilaparvata lugens ( Stal ) ( Hemiptera : Delphacidae ) .
We compared two mutants that showed a gain and loss of resistance to N lugens , to determine the categories of resistance to this pest Under choice tests , female planthoppers avoided settling and laid fewer eggs on the resistant mutant D518 than on the susceptible mutant D1131 , susceptible check TN1 , and wild-type IR64 , indicating that antixenosis was the resistance category .
Similarly , under no-choice conditions , planthoppers laid 29% fewer eggs in D518 than in IR64 , but they oviposited more in D1131 and TN1 .
Honeydew excretion was greater on D1131 seedlings but slightly lower on D518 than on IR64 .
Nymphal survival and adult female weight did not differ among rice cultivars .
D518 showed higher tolerance of N lugens infestations than IR64 .
Genetic analysis of the F1 , F2 , and F3 populations derived from D518 x IR64 revealed that resistance in D518 is dominant and controlled by a single gene .
Despite the variation in resistance to N lugens , both mutants and IR64 performed similarly in the field .
The mutant D518 is a new source of durable resistance to N lugens , mainly due to enhanced antixenosis to female hoppers for settling and oviposition .
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Score: 1.00 |
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| Title: Isoform-specific effects of charged residues at borders of the M1-M2 loop of the Na , K-ATPase alpha subunit .
| | Author: Coppi MV Compton LA Guidotti G | | Journal: Biochemistry Citation: V : 38 ( 8 ) P : 2494-505 Year: 1999 Type: ARTICLE | | Literature: oryza Field: abstract Doc ID: pub10029544 Accession (PMID): 10029544 | | Abstract: The Na , K-ATPase is specifically inhibited by the cardiac glycoside , ouabain .
Via a largely undefined mechanism , the ouabain affinity of the Na , K-ATPase can be manipulated by mutating the residues at the borders of the first extracellular ( M1-M2 ) loop of the alpha subunit [ Price , E M , Rice , D A , and Lingrel , J B ( 1990 ) J Biol . Chem . 265 , 6638-6641 ] .
To address this issue , we compared the effects of two combinations of charged residues at the M1-M2 loop border , R113 , D124 and D113 , R124 ( numbered according to the rat alpha1 subunit ) , on the ouabain sensitivity of the alpha1 and alpha2 isoforms .
We report that ouabain sensitivity is dependent not only upon the identity of the residues at the M1-M2 loop border but also upon the context into which they are introduced .
Furthermore , at low concentrations of ATP , the identity of the residues at the M1-M2 loop border affects the regulation of ATP hydrolysis by potassium in an isoform-specific manner .
Analysis of chimeric alpha subunits reveals that the effects of potassium are determined primarily by the interaction of the N-terminus and M1-M2 loop with the C-terminal third of the alpha subunit .
M1-M2 loop border residues may , therefore , influence ouabain sensitivity indirectly by altering the stability or structure of the intermediate of the Na , K-ATPase catalytic cycle which is competent to bind ouabain .
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Score: 1.00 |
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| Title: The Rice brassinosteroid-deficient dwarf2 mutant , defective in the rice homolog of Arabidopsis DIMINUTO/DWARF1 , is rescued by the endogenously accumulated alternative bioactive brassinosteroid , dolichosterone .
| | Author: Hong Z Ueguchi-Tanaka M Fujioka S Takatsuto S Yoshida S Hasegawa Y Ashikari M Kitano H Matsuoka M | | Journal: Plant Cell Citation: V : 17 ( 8 ) P : 2243-54 Year: 2005 Type: ARTICLE | | Literature: oryza Field: abstract Doc ID: pub15994910 Accession (PMID): 15994910 | | Abstract: We have identified a rice ( Oryza sativa ) brassinosteroid ( BR ) -deficient mutant , BR-deficient dwarf2 ( brd2 ) .
The brd2 locus contains a single base deletion in the coding region of Dim/dwf1 , a homolog of Arabidopsis thaliana DIMINUTO/DWARF1 ( DIM/DWF1 ) .
Introduction of the wild-type Dim/dwf1 gene into brd2 restored the normal phenotype .
Overproduction and repression of Dim/dwf1 resulted in contrasting phenotypes , with repressors mimicking the brd2 phenotype and overproducers having large stature with increased numbers of flowers and seeds .
Although brd2 contains low levels of common 6-oxo-type BRs , the severity of the brd2 phenotype is much milder than brd1 mutants and most similar to d2 and d11 , which show a semidwarf phenotype at the young seedling stage .
Quantitative analysis suggested that in brd2 , the 24-methylene BR biosynthesis pathway is activated and the uncommon BR , dolichosterone ( DS ) , is produced .
DS enhances the rice lamina joint bending angle , rescues the brd1 dwarf phenotype , and inhibits root elongation , indicating that DS is a bioactive BR in rice .
Based on these observations , we discuss an alternative BR biosynthetic pathway that produces DS when Dim/dwf1 is defective . | | Supplemental links/files: reference in endnote online text related articles pubmed citation | |
Score: 1.00 |
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| Title: Involvement of C-22-hydroxylated brassinosteroids in auxin-induced lamina joint bending in rice .
| | Author: Nakamura A Fujioka S Takatsuto S Tsujimoto M Kitano H Yoshida S Asami T Nakano T | | Journal: Plant Cell Physiol Citation: V : 50 P : 1627-35 Year: 2009 Type: MEDLINE | | Literature: oryza Field: abstract Doc ID: pub19605414 Accession (PMID): 19605414 | | Abstract: The rice lamina joint is ideal material for investigating the activity of brassinosteroids ( BRs ) and auxin because of its high sensitivity to these compounds .
Using a series of rice BR biosynthetic and receptor mutants , we conducted lamina joint tests to elucidate the mechanism of cross-talk between BR and auxin signaling in lamina joint bending .
In BR biosynthetic mutants d2 and brd1 , which are defective in C-23 hydroxylase and C-6 oxidase , respectively , the lamina joint response to auxin was significantly higher than that of wild-type plants .
The other BR-biosynthetic mutants , brd2 , osdwarf4 and d11 , which are defective in C-22-hydroxylated BRs , showed less or no response to auxin .
These results suggest that C-22-hydroxylated BRs are involved in auxin-induced lamina joint bending .
The results were supported by the observation that inhibition of the hyper-response to auxin in d2 was reduced by treatment with brassinazole , which inhibits the function of DWARF4 , the C-22 hydroxylase .
In d61 , which is defective in OsBRI1 , a possible BR receptor in rice , the bending angle of the lamina joint in response to auxin and C-22-hydroxylated 6-deoxoBRs was nearly the same as that in wild-type plants .
This implies that C-22-hydroxylated BRs function in auxin signaling independently of OsBRI1 .
From these observations , we propose that C-22-hydroxylated BRs participate in auxin signaling via a novel OsBRI1-independent signaling pathway .
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Score: 1.00 |
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| Title: RAV-Like1 maintains brassinosteroid homeostasis via the coordinated activation of BRI1 and biosynthetic genes in rice .
| | Author: Je BI Piao HL Park SJ Park SH Kim CM Xuan YH Park SH Huang J Do Choi Y An G Wong HL Fujioka S Kim MC Shimamoto K Han CD | | Journal: Plant Cell Citation: V : 22 P : 1777-91 Year: 2010 Type: MEDLINE | | Literature: oryza Field: abstract Doc ID: pub20581303 Accession (PMID): 20581303 | | Abstract: Temporal and spatial variation in the levels of and sensitivity to hormones are essential for the development of higher organisms .
Traditionally , end-product feedback regulation has been considered as the key mechanism for the achievement of cellular homeostasis .
Brassinosteroids ( BRs ) are plant steroid hormones that are perceived by the cell surface receptor kinase Brassinosteroid Insensitive1 .
Binding of these hormones to the receptor activates BR signaling and eventually suppresses BR synthesis .
This report shows that RAVL1 regulates the expression of the BR receptor .
Furthermore , RAVL1 is also required for the expression of the BR biosynthetic genes D2 , D11 , and BRD1 that are subject to BR negative feedback .
Activation by RAVL1 was coordinated via E-box cis-elements in the promoters of the receptor and biosynthetic genes .
Also , RAVL1 is necessary for the response of these genes to changes in cellular BR homeostasis .
Genetic evidence is presented to strengthen the observation that the primary action of RAVL1 mediates the expression of genes involved in BR signaling and biosynthesis .
This study thus describes a regulatory circuit modulating the homeostasis of BR in which RAVL1 ensures the basal activity of both the signaling and the biosynthetic pathways .
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Score: 1.00 |
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| Title: A tomato cDNA inducible by salt stress and abscisic acid : nucleotide sequence and expression pattern .
| | Author: Godoy JA Pardo JM Pintor-Toro JA .
| | Journal: Plant Mol . Biol . Citation: V : 15 ( 5 ) P : 695-705 Year: 1990 Type: ARTICLE | | Literature: oryza Field: abstract Doc ID: pub2151719 Accession (PMID): 2151719 | | Abstract: We have characterized a new tomato cDNA , TAS14 , inducible by salt stress and abscisic acid ( ABA ) .
Its nucleotide sequence predicts an open reading frame coding for a highly hydrophilic and glycine-rich ( 23 . 8% ) protein of 130 amino acids .
Southern blot analysis of tomato DNA suggests that there is one TAS14 structural gene per haploid genome .
TAS14 mRNA accumulates in tomato seedlings upon treatment with NaCl , ABA or mannitol .
It is also induced in roots , stems and leaves of hydroponically grown tomato plants treated with NaCl or ABA .
TAS14 mRNA is not induced by other stress conditions such as cold and wounding .
The sequence of the predicted TAS14 protein shows four structural domains similar to the rice RAB21 , cotton LEA D11 and barley and maize dehydrin genes .
| | Supplemental links/files: reference in endnote online text related articles pubmed citation | |
Score: 1.00 |
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| Title: H3K36 methylation is critical for brassinosteroid-regulated plant growth and development in rice .
| | Author: Sui P Jin J Ye S Mu C Gao J Feng H Shen WH Yu Y Dong A | | Journal: Plant J Citation: V : 70 P : 340-7 Year: 2012 Type: MEDLINE | | Literature: oryza Field: abstract Doc ID: pub22136623 Accession (PMID): 22136623 | | Abstract: Methylation of histone lysine residues plays an essential role in epigenetic regulation of gene expression in eukaryotes .
Enzymes involved in establishment of the repressive H3K9 and H3K27 methylation marks have been previously characterized , but the deposition and function of H3K4 and H3K36 methylation remain uncharacterized in rice .
Here , we report that rice SDG725 encodes a H3K36 methyltransferase , and its down-regulation causes wide-ranging defects , including dwarfism , shortened internodes , erect leaves and small seeds .
These defects resemble the phenotypes previously described for some brassinosteroid-knockdown mutants .
Consistently , transcriptome analyses revealed that SDG725 depletion results in down-regulation by more than two-fold of over 1000 genes , including D11 , BRI1 and BU1 , which are known to be involved in brassinosteroid biosynthesis or signaling pathways .
Chromatin immunoprecipitation analyses showed that levels of H3K36me2/3 are reduced in chromatin at some regions of these brassinosteroid-related genes in SDG725 knockdown plants , and that SDG725 protein is able to directly bind to these target genes .
Taken together , our data indicate that SDG725-mediated H3K36 methylation modulates brassinosteroid-related gene expression , playing an important role in rice plant growth and development .
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Score: 1.00 |
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| Title: Differential expression of a gene encoding an acidic dehydrin in chilling sensitive and freezing tolerant gramineae species .
| | Author: Danyluk J Houde M Rassart E Sarhan F | | Journal: FEBS Lett .
Citation: V : 344 ( 1 ) P : 20-4 Year: 1994 Type: ARTICLE | | Literature: oryza Field: abstract Doc ID: pub7910142 Accession (PMID): 7910142 | | Abstract: We have characterized a new wheat cold-regulated cDNA clone , Wcor410 , that accumulates to equivalent levels in root , crown and leaf it issues during cold acclimation .
The Wcor410 cDNA contains an ORF encoding a dehydrin-like glutamate-rich protein of 28 kDa with a pI of 5 . 1 .
However , the acidic nature , the absence of the glycine-rich repeat and of the conserved N-terminal region , DEYGNP , suggest that Wcor410 belongs to a different subgroup of the D11 protein family .
Northern analysis showed that this gene is expressed only in freezing tolerant gramineae , whereas Southern analysis showed that the Wcor410 gene is present in all monocot species tested .
The presence of freezing tolerance-associated genes in sensitive species such as rice and corn is interesting .
Characterization of the regulatory factors controlling these genes may help to establish an appropriate strategy to improve freezing tolerance .
| | Supplemental links/files: reference in endnote online text related articles pubmed citation | |
