Na Chen

Publications (5)17.28 Total impact

• Source

  Available from: Kang Chong

  Article: OsRAN2, essential for mitosis, enhances cold tolerance in rice by promoting export of intranuclear tubulin and maintaining cell division under cold stress.

  Na Chen, Yunyuan Xu, Xin Wang, Cheng DU, Jizhou DU, Ming Yuan, Zhihong Xu, Kang Chong
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  ABSTRACT: With global climate change, abnormally low temperatures have affected the world's rice production. Many genes have been shown to be essential for molecular improvement of rice cold-tolerance traits. However, less is known about the molecular cellular mechanism of their response to cold stress. Here, we investigated OsRAN2 involved in regulation of cell division during cold stress in rice. Expression of OsRAN2 was increased under cold treatment, but not during salt and drought stress. The mean root mitotic index was closely related to the expression level of OsRAN2. Knockdown transgenic rice lines showed an aberrant organization of spindles during mitosis and stunted growth during development. Overexpression of OsRAN2 enhanced cold tolerance in rice. The transgenic rice overexpressing OsRAN2 showed maintained cell division, decreased proportion of cells with intranuclear tubulin and formation of a normal nuclear envelope under the cold condition. Our study suggests a mechanism for OsRAN2 in regulating cold resistance in rice by maintaining cell division through promoting the normal export of intranuclear tubulin at the end of mitosis. This insight could help improve the cold-tolerance trait in rice.
  Plant Cell and Environment 01/2011; 34(1):52-64. · 5.22 Impact Factor
• Article: Enhanced tolerance to chilling stress in OsMYB3R-2 transgenic rice is mediated by alteration in cell cycle and ectopic expression of stress genes.

  Qibin Ma, Xiaoyan Dai, Yunyuan Xu, Jing Guo, Yaju Liu, Na Chen, Jun Xiao, Dajian Zhang, Zhihong Xu, Xiansheng Zhang, Kang Chong
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  ABSTRACT: MYB transcription factors play central roles in plant responses to abiotic stresses. How stress affects development is poorly understood. Here, we show that OsMYB3R-2 functions in both stress and developmental processes in rice (Oryza sativa). Transgenic plants overexpressing OsMYB3R-2 exhibited enhanced cold tolerance. Cold treatment greatly induced the expression of OsMYB3R-2, which encodes an active transcription factor. We show that OsMYB3R-2 specifically bound to a mitosis-specific activator cis-element, (T/C)C(T/C)AACGG(T/C)(T/C)A, a conserved sequence that was found in promoters of cyclin genes such as OsCycB1;1 and OsKNOLLE2. In addition, overexpression of OsMYB3R-2 in rice led to higher transcript levels of several G2/M phase-specific genes, including OsCycB1;1, OsCycB2;1, OsCycB2;2, and OsCDC20.1, than those in OsMYB3R-2 antisense lines or wild-type plants in response to cold treatment. Flow cytometry analysis revealed an increased cell mitotic index in overexpressed transgenic lines of OsMYB3R-2 after cold treatment. Furthermore, resistance to cold stress in the transgenic plants overexpressing OsCycB1;1 was also enhanced. The level of cellular free proline was increased in the overexpressed rice lines of OsMYB3R-2 and OsCycB1;1 transgenic plants compared with wild-type plants under the cold treatment. These results suggest that OsMYB3R-2 targets OsCycB1;1 and regulates the progress of the cell cycle during chilling stress. OsCPT1, which may be involved in the dehydration-responsive element-binding factor 1A pathway, showed the same transcription pattern in response to cold as did OsCycB1;1 in transgenic rice. Therefore, a cold resistance mechanism in rice could be mediated by regulating the cell cycle, which is controlled by key genes including OsMYB3R-2.
  Plant physiology 04/2009; 150(1):244-56. · 6.53 Impact Factor
• Article: Overexpression of sweet pepper glycerol-3-phosphate acyltransferase gene enhanced thermotolerance of photosynthetic apparatus in transgenic tobacco.

  Kun Yan, Na Chen, Yan-Yan Qu, Xin-Chun Dong, Qing-Wei Meng, Shi-Jie Zhao
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  ABSTRACT: In order to investigate the relationship between the lipid composition in thylakoid membrane and thermostability of photosynthetic apparatus, tobacco transformed with sweet pepper sense glycerol-3-phosphate acyltransferase (GPAT) gene were used to analyze the lipid composition in thylakoid membrane, the net photosynthetic rate and chlorophyll fluorescence parameters under high temperature stress. The results showed that the saturated extent of monogalactosyldiacylglycerol (MGDG), sulfoquinovosyldiacylglycerol, digalactosyldiacylglycerol and phosphatidylglycerol in thylakoid membrane of transgenic tobacco T(1) lines increased generally. Particularly, the saturated extent in MGDG increased obviously by 16.2% and 12.0% in T(1)-2 and T(1)-1, respectively. With stress temperature elevating, the maximum efficiency of photosystem II (PSII) photochemistry (Fv/Fm), actual photochemical efficiency of PSII in the light (Phi(PSII)) and net photosynthetic rate (Pn) of the two lines and wild type tobacco plants decreased gradually, but those parameters decreased much less in transgenic plants. Even though the recovery process appeared differently in the donor and acceptor side of PSII in transgenic tobacco compared with wild-type plants, the entire capability of PSII recovered faster in transgenic tobacco, which was shown in the parameters of PI, Fv/Fm and Phi(PSII), as a result, the recovery of Pn was accelerated. Conclusively, we proposed that the increase in saturated extent of thylakoid membrane lipids in transgenic plants enhanced the stability of photosynthetic apparatus under high temperature stress.
  Journal of Integrative Plant Biology 06/2008; 50(5):613-21. · 2.53 Impact Factor
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  Available from: Kang Chong

  Article: Overexpression of OsCOIN, a putative cold inducible zinc finger protein, increased tolerance to chilling, salt and drought, and enhanced proline level in rice.

  Kaimao Liu, Lei Wang, Yunyuan Xu, Na Chen, Qibin Ma, Fei Li, Kang Chong
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  ABSTRACT: Rice (Oryza sativa L.) plant is sensitive to chilling, particularly at early stages of seedling development. Here a novel cold-inducible gene, designated OsCOIN (Oryza sativa cold-inducible), was isolated and characterized. Results showed that OsCOIN protein, a RING finger protein, was localized in both nuclear and cytoplasm membrane. OsCOIN is expressed in all rice organs and strongly induced by low temperature, ABA, salt and drought. Over-expression of OsCOIN in transgenic rice lines significantly enhanced their tolerance to cold, salt and drought, accompanied by an up-regulation of OsP5CS expression and an increase of cellular proline level.
  Planta 10/2007; 226(4):1007-16. · 3.00 Impact Factor
• Article: [cDNA cloning and expression of a cytosolic small heat shock protein gene (CaHSP18) from Capsicum annuum].

  Shang-Jing Guo, Na Chen, Peng Guo, Qing-Wei Meng
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  ABSTRACT: Full length 779 bp cytosolic clsss I sHSP cDNA was cloned from heat-shocked sweet pepper leaves using a PCR approach with degenerate primers designed from conserved motifs found in a number of plant cytosolic clsss I sHSP genes, named CaHSP18. Its accession number is AY284925. CaHSP18 was high identified with Nicotiana tabacum (Fig.1). A multi-gene family was found in sweet pepper genomic DNA by Southern-blot analysis (Fig.3). Northern blot revealed that the expression of CaHSP18 in sweet pepper was induced by heat treatment and was significantly different between different tissues (Fig.4). The transcription of CaHSP18 in leaves and stems were higher than those in roots. The expression of CaHSP18 could be detected after chilling treatment at 4 degrees C for 2 d. Recombinant CaHSP18 was overexpressed in Escherichia coli to study its possible function under heat and chilling stress. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of cell lysates suggested that CaHSP18 was expressed in Escherichia coli (Fig.6). The growth of wild type and transformed cells was similar at 37 degrees C (Fig. 5). Upon transfer from 37 degrees C to 50 degrees C, a temperature known to cause cell autolysis, those cells that accumulated CaHSP18 showed improved viability compared with the control lines (Fig.7). To test the hypothesis that sHSPs may be involved in protection against chilling stress, the viability of recombinant cells at 4 degrees C was studied. The sweet pepper CaHSP18 significantly enhanced cell survivability (Fig.8). These results indicate that plant cytosolic clsss I sHSP have protective functions not only against heat stress but also against chilling stress.
  Zhi wu sheng li yu fen zi sheng wu xue xue bao = Journal of plant physiology and molecular biology 09/2005; 31(4):409-16.