Difference between revisions of "Os03g0125100"

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(Mutation)
(Annotated Information)
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'''GO assignment(s):''' [http://amigo.geneontology.org/amigo/term/GO:0003824 GO:0003824],[http://amigo.geneontology.org/amigo/term/GO:0008152 GO:0008152]
 
'''GO assignment(s):''' [http://amigo.geneontology.org/amigo/term/GO:0003824 GO:0003824],[http://amigo.geneontology.org/amigo/term/GO:0008152 GO:0008152]
 
 
===Mutation===
 
===Mutation===
 
* T-DNA insertion mutants in the background of japonica Zhonghua11 (ZH11) rice, selected from the Rice Mutant Database, for drought resistance under field conditions was screened by the researchers to identify critical genes required for drought resistance in rice. One of the drought-hypersensitive mutants showing drought sensitivity at both the seedling and panicle development stages, designated as ''dsm2-1'', was further characterized in this study.
 
* T-DNA insertion mutants in the background of japonica Zhonghua11 (ZH11) rice, selected from the Rice Mutant Database, for drought resistance under field conditions was screened by the researchers to identify critical genes required for drought resistance in rice. One of the drought-hypersensitive mutants showing drought sensitivity at both the seedling and panicle development stages, designated as ''dsm2-1'', was further characterized in this study.
  
 
* To verify the drought-sensitive phenotype, mutant and wild-type plants at the four-leaf stage grown in sandy soil were subjected to drought stress. Under the moderate stress condition, the dsm2 mutant lines wilted faster than the wild type. After severe drought stress treatment followed by rewatering, almost all the mutant plants died, whereas wild-type plants had a significantly higher survival rate (Fig. 1C). Cosegregation analysis also suggested that the drought sensitivity was due to the T-DNA insertion in the OsBCH1 gene (data not shown). The dsm2-1 mutant was also more sensitive than the wild type to salt stress, but no significant difference was observed under cold or heat shock stress.
 
* To verify the drought-sensitive phenotype, mutant and wild-type plants at the four-leaf stage grown in sandy soil were subjected to drought stress. Under the moderate stress condition, the dsm2 mutant lines wilted faster than the wild type. After severe drought stress treatment followed by rewatering, almost all the mutant plants died, whereas wild-type plants had a significantly higher survival rate (Fig. 1C). Cosegregation analysis also suggested that the drought sensitivity was due to the T-DNA insertion in the OsBCH1 gene (data not shown). The dsm2-1 mutant was also more sensitive than the wild type to salt stress, but no significant difference was observed under cold or heat shock stress.
 
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**T-DNA Insertion Mutation
===T-DNA Insertion Mutation===
 
  
 
===Expression===
 
===Expression===

Revision as of 08:33, 1 July 2016

The gene Os03g0125100 (LOC_Os03g03370) was reported as DSM2 in 2009. It encodes a putative BCH (named DSM2/OsBCH1) belonging to the BCH family[1]. This gene was also named OsHYD3[2].

Annotated Information

Function

The rice DSM2 gene significantly contributes to control of the xanthophyll cycle and ABA synthesis, both of which play critical roles in the establishment of drought resistance in rice.'[1].

GO assignment(s): GO:0003824,GO:0008152

Mutation

  • T-DNA insertion mutants in the background of japonica Zhonghua11 (ZH11) rice, selected from the Rice Mutant Database, for drought resistance under field conditions was screened by the researchers to identify critical genes required for drought resistance in rice. One of the drought-hypersensitive mutants showing drought sensitivity at both the seedling and panicle development stages, designated as dsm2-1, was further characterized in this study.
  • To verify the drought-sensitive phenotype, mutant and wild-type plants at the four-leaf stage grown in sandy soil were subjected to drought stress. Under the moderate stress condition, the dsm2 mutant lines wilted faster than the wild type. After severe drought stress treatment followed by rewatering, almost all the mutant plants died, whereas wild-type plants had a significantly higher survival rate (Fig. 1C). Cosegregation analysis also suggested that the drought sensitivity was due to the T-DNA insertion in the OsBCH1 gene (data not shown). The dsm2-1 mutant was also more sensitive than the wild type to salt stress, but no significant difference was observed under cold or heat shock stress.
    • T-DNA Insertion Mutation

Expression

  • Overexpression of DSM2 in rice resulted in significantly increased resistance to drought and oxidative stresses and increases of the xanthophylls and nonphotochemical quenching. Some stress-related ABA responsive genes were up-regulated in the overexpression line[1].
  • Transcript analysis suggested that the expression of DSM2 was abolished in the two allelic dsm2 mutants. The DSM2 transcript level was induced (7- to 9-fold) by drought and salt treatments and slightly induced by ABA. However, DSM2 was not induced by the other treatments (and was slightly suppressed by cold stress)[1].
  • A strong GFP signal was observed in the stamen, plumule, hull, pistil,mature leaf, and root, and a weak GFP signal was detected in calli, young shoot and root, and endosperm, suggesting an organ/ tissue-dependent differential expression pattern of DSM2 in rice[1].

Evolution

In the rice genome, there are two homologs of DSM2/ OsBCH1, designated OsBCH2 (LOC_Os04g48880) and OsBCH3 (LOC_Os10g38940), showing 82% and 75% identity to OsBCH1, respectively. DSM2 belongs to the BCH family[1].

Knowledge Extension

  • The CYP97 and BCH gene pairs are primarily responsible for hydroxylation of α- and β-carotenes, respectively, but exhibit some overlapping activities, most notably in hydroxylation of the β-ring of α-carotene. The BCH duplicates encode isozymes that show significant expression divergence in reproductive organs[3].
  • The two BCH isozymes could hydroxylate the β-ring of α-carotene, though again to a lower extent than the full four enzyme complement in the wild type[3].

Labs working on this gene

  • National Key Laboratory of Crop Genetic Improvement, National Center of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan 430070, China

References

  1. 1.0 1.1 1.2 1.3 1.4 1.5 Du H, Wang N, Cui F, et al. Characterization of the β-carotene hydroxylase gene DSM2 conferring drought and oxidative stress resistance by increasing xanthophylls and abscisic acid synthesis in rice[J]. Plant Physiology, 2010, 154(3): 1304-1318.
  2. Vallabhaneni R, Gallagher C E, Licciardello N, et al. Metabolite sorting of a germplasm collection reveals the hydroxylase3 locus as a new target for maize provitamin A biofortification[J]. Plant physiology, 2009, 151(3): 1635-1645.
  3. 3.0 3.1 Kim J, Smith J J, Tian L, et al. The evolution and function of carotenoid hydroxylases in Arabidopsis[J]. Plant and cell physiology, 2009, 50(3): 463-479.

Structured Information