Chao Ma

Publications (2)8.3 Total impact

• Article: Overexpression of two chrysanthemum DgDREB1 group genes causing delayed flowering or dwarfism in Arabidopsis.

  Zheng Tong, Bo Hong, Yingjie Yang, Qiuhua Li, Nan Ma, Chao Ma, Junping Gao
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  ABSTRACT: We isolated 13 DREB1 (dehydration responsive element binding factor 1) genes from chrysanthemum and further divided them into three groups, DgDREB1A, DgDREB1B and DgDREB1C, based on the phylogenetic analysis. Each group showed their unique expression patterns under cold, dehydration and salt stress conditions. Arabidopsis plants overexpressing DgDREB1A (1A plants) exhibited significantly stronger tolerance to freezing and drought than those overexpressing DgDREB1B (1B plants) and the control plants. In addition, 1A plants showed delayed flowering, but not dwarfism; while 1B plants showed dwarfism, but not delayed flowering. In 1A plants, the expression of three stress-related DREB1-downstream genes, COR47, COR15A, and RD29A, was strongly induced while the expression of CO and FT, two photoperiod responsive flowering-time genes, was inhibited. In 1B plants, the expression of GA2ox7, a GA-deactivation enzyme gene, was dramatically enhanced. The results above strongly suggest that members from different DgDREB1 groups may have distinct effects on plant development: DgDREB1A may be involved in photoperiod-related flowering-time determination and DgDREB1B in GA-mediated plant development.
  Plant Molecular Biology 07/2009; 71(1-2):115-29. · 4.15 Impact Factor
• Article: Over-expression of AtDREB1A in chrysanthemum enhances tolerance to heat stress.

  Bo Hong, Chao Ma, Yingjie Yang, Ting Wang, Kazuko Yamaguchi-Shinozaki, Junping Gao
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  ABSTRACT: The effect of over-expression of AtDREB1A gene in chrysanthemums on heat stress tolerance was investigated. Transgenic plants with 35S:AtDREB1A construct (henceforth, 35S plants) and wild type (WT) plants were exposed to 45 degrees C as a heat stress treatment. When heat-treated for 36 h and followed by a 3-week recovery, approximately 70% of the 35S plants, but less than 20% of the WT plants were survived. Leaf electrolyte leakage was significantly lower in 35S plants than in WT plants. cDNA macroarray analysis showed that 55 of 74 DREB1A regulon members were up-regulated under heat stress in WT plants. In comparison with WT plants, 35S plants displayed greatly enhanced expression of the genes including signal transduction, transcription and HSP70 in the early time, and the genes including photosynthesis and metabolism in the late time of the heat treatment. We also found that the 35S plants maintained significantly higher photosynthetic capacity, and elevated activity of Rubisco and sucrose-phosphate synthase under heat stress. These results suggest that improvement of heat stress tolerance in transgenic chrysanthemum may be associated with enhanced tolerance of photosynthesis.
  Plant Molecular Biology 03/2009; 70(3):231-40. · 4.15 Impact Factor