Score: 3.00 |
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| Title: Epidermal cell death in rice is confined to cells with a distinct molecular identity and is mediated by ethylene and H2O2 through an autoamplified signal pathway .
| | Author: Steffens B Sauter M | | Journal: Plant Cell Citation: V : 21 P : 184-96 Year: 2009 Type: MEDLINE | | Literature: oryza Field: abstract Doc ID: pub19141708 Accession (PMID): 19141708 | | Abstract: Rice ( Oryza sativa ) forms adventitious root primordia at stem nodes during normal development .
Root emergence is preceded by ethylene-induced , H ( 2 ) O ( 2 ) -mediated local death of epidermal cells .
Exogenous H ( 2 ) O ( 2 ) or enhancement of endogenous H ( 2 ) O ( 2 ) promoted epidermal cell death in a dose-dependent manner .
Inhibition of NADPH oxidase lowered ethylene-induced cell death rates .
Inhibition of ethylene perception by 1-methylcyclopropene did not abolish H ( 2 ) O ( 2 ) -induced cell death , indicating that H ( 2 ) O ( 2 ) acts downstream of ethylene .
Microarray studies of epidermal cells that undergo cell death identified 61 genes coregulated by the ethylene-releasing compound ethephon and by H ( 2 ) O ( 2 ) , supporting a joint signaling pathway .
Regulation of the ethylene biosynthetic genes 1-Aminocyclopropane-1-Carboxylate Oxidase1 and Ethylene Overproducer-Like1 and downregulation of Metallothionein2b ( MT2b ) , which encodes a reactive oxygen scavenger , indicated mutual enhancement of ethylene and H ( 2 ) O ( 2 ) signaling .
Analysis of MT2b knockdown mutants showed that cell death rates were inversely related to MT2b transcript abundance .
Epidermal cells above adventitious roots have a morphological and molecular identity distinct from other epidermal cells .
Pro-death signals regulated several transcription factor genes with a proposed function in cell type specification .
It is hypothesized that induction of cell death is dependent on epidermal cell identity .
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[ Sen. 8, subscore: 2.00 ]: Analysis of MT2b knockdown mutants showed that cell death rates were inversely related to MT2b transcript abundance .
[ Sen. 7, subscore: 1.00 ]: Regulation of the ethylene biosynthetic genes 1-Aminocyclopropane-1-Carboxylate Oxidase1 and Ethylene Overproducer-Like1 and downregulation of Metallothionein2b ( MT2b ) , which encodes a reactive oxygen scavenger , indicated mutual enhancement of ethylene and H ( 2 ) O ( 2 ) signaling .
| | Supplemental links/files: reference in endnote online text related articles pubmed citation | |
Score: 2.00 |
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| Title: Aerenchyma formation in the rice stem and its promotion by H2O2 .
| | Author: Steffens B Geske T Sauter M | | Journal: New Phytol Citation: V : 190 P : 369-78 Year: 2011 Type: MEDLINE | | Literature: oryza Field: abstract Doc ID: pub21039565 Accession (PMID): 21039565 | | Abstract: * Gas spaces ( aerenchyma ) form as an adaptation to submergence to facilitate gas exchange .
In rice ( Oryza sativa ) , aerenchyma develop by cell death and lysis , which are poorly understood at the cellular level .
* Aerenchyma formation was studied in rice stems by light microscopy .
It was analyzed in response to submergence , ethylene and hydrogen peroxide ( H ( 2 ) O ( 2 ) ) treatment , and in the MT2b : : Tos17 mutant .
O ( 2 ) . ( - ) was detected with nitroblue tetrazolium and an epinephrine assay .
H ( 2 ) O ( 2 ) was detected with 3 , 3-diaminobenzidine .
* Aerenchyma develop constitutively in all internodes of the deep-water rice variety Pin Gaew 56 , but are absent from the nodes .
Constitutive aerenchyma formation was also observed in two lowland rice varieties , albeit to a lesser degree .
A larger number of aerenchyma are present in older internodes , and at the top of each internode , revealing developmental gradients .
Submergence or treatment with the ethylene-releasing compound ethephon promoted aerenchyma formation in all genotypes analyzed .
Pre-aerenchymal cells contain less starch , no chloroplasts , thinner cell walls and produce elevated levels of O ( 2 ) . ( - ) and H ( 2 ) O ( 2 ) compared with other parenchymal cells .
Ethephon promotes O ( 2 ) . ( - ) formation and H ( 2 ) O ( 2 ) promotes aerenchyma formation in a dose-dependent manner .
Further-more , genetic downregulation of the H ( 2 ) O ( 2 ) scavenger MT2b enhances aerenchyma formation .
* Aerenchyma formation is mediated by reactive oxygen species .
| Matching Sentences:
[ Sen. 4, subscore: 1.00 ]: It was analyzed in response to submergence , ethylene and hydrogen peroxide ( H ( 2 ) O ( 2 ) ) treatment , and in the MT2b : : Tos17 mutant .
[ Sen. 13, subscore: 1.00 ]: Further-more , genetic downregulation of the H ( 2 ) O ( 2 ) scavenger MT2b enhances aerenchyma formation .
| | Supplemental links/files: reference in endnote online text related articles pubmed citation | |
