The rice Os01g0192000 is located at rice chromosome 1, which is involved in delaying leaf senescence in rice. It was reported as OsDOS by Chinese plant molecular biologists in 2006.
- Leaf senescence is a developmentally programmed degeneration process that constitutes the final step of leaf development and is controlled by multiple developmental and environmental signals.
- Research shows that OsDOS acts as a novel negative regulator for leaf senescence by integrating developmental cues to senescence signaling cascades including the JA pathway.
- Scientists propose that OsDOS possibly plays a role at posttranscriptional level in delaying leaf senescence in rice. And the potential targets of OsDOS might be key positive elements that are required to promote the leaf senescence program.
Wild Type & Mutants
- RNAi interference of the OsDOS. The RNAi T 1 lines appeared normal during the vegetative growth. However, beginning at the time of late booting stage, slight but consistent leaf yellowing was clearly observed in the RNAi lines and then an accelerated leaf senescence occurred compared with that in the wild-type plants.
- At the grainfilling stage, striking leaf yellowing appeared in the whole plant, except the flag leaf showing a slightly less yellowing, and the senescence symptom was correlated with the reduction of the expression level of OsDOS.
- Compared with the OsDOS RNAi lines, the wild-type plants stayed much more green.
- Overexpression of the OsDOS. The OsDOS OX lines showed a delay in growth, shorter stature, abnormally developed panicle, deferred heading, and severe sterility.
- The florets of the OsDOS OX lines was found failed to open or scarcely opened after heading. Further phenotypic analysis showed that defects in anther dehiscence and pollen viability may be responsible for the severe sterility of the OX lines.
- Together, these results indicated that the ectopic overexpression of OsDOS has a pleiotropic impact on rice development.
- Real-time PCR analysis was performed to examine the expression profile of OsDOS. The OsDOS transcripts were detected throughout the plant, in panicles and leaves with a higher expression at the early stages. the temporal expression profiles of the OsDOS transcripts indicated a down-regulation of the OsDOS gene expression during natural leaf senescence. Down-regulation of the OsDOS expression also occurred during the panicle development process. In addition, the expression level of OsDOS was reduced after pollination
- RNA in situ hybridization analysis was also conducted to further examine tissue-specific expression patterns of OsDOS. Strong OsDOS expression was detected in the leaf primordium, incipient leaf, and shoot meristem, but weak expression was observed in the elder leaf tissue
- To examine the subcellular localization of OsDOS, a green fluorescent protein (GFP) reporter gene was fused in frame to the last codon of the OsDOS coding region to produce an OsDOS-GFP fusion protein in transgenic rice plants. And the OsDOS-GFP green fluorescent signal was detected predominantly in the nuclei of the transgenic rice plants. These results indicate that OsDOS is a nuclear-localized protein and presumably functions as a transcript regulator as predicted for other CCCH-type proteins.
Labs working on this gene
- Laboratory of Molecular and Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100080, China.
- National Centre for Plant Gene Research, Beijing 100080, China
- Graduate University of Chinese Academy of Sciences, Beijing 100049, China
- College of Life Sciences, Tianjin Normal University, Tianjin 300074, China
- ↑ 1.0 1.1 1.2 Kong Z, Li M, Yang W, Xu W, Xue Y. A novel nuclear-localized CCCH-type zinc finger protein, OsDOS, is involved in delaying leaf senescence in rice. Plant Physiol. 2006 Aug;141(4):1376-88. Epub 2006 Jun 15. PubMed PMID: 16778011