title: Uniconazole-induced starch accumulation in the bioenergy crop duckweed (Landoltia punctata) I: transcriptome analysis of the effects of uniconazole on chlorophyll and endogenous hormone biosynthesis.
abstract: BACKGROUND
  Duckweed is a novel aquatic bioenergy crop that is found ubiquitously throughout the world. Uniconazole plays an important role in improving crop production through the regulation of endogenous hormone levels. We found that a high quantity and quality of duckweed growth can be achieved by uniconazole application, although the mechanisms are unknown.
  
  
  RESULTS
  The fronds of Landoltia punctata were sprayed evenly with 800 mg/L uniconazole. The dry weight following treatment increased by 10% compared to the controls at 240 h. Endogenous cytokinin (CK) and abscisic acid (ABA) content both increased compared to the control, while the level of gibberellins (GAs) decreased. Additionally, gene expression profiling results showed that the expression of transcripts encoding key enzymes involved in endogenous CK and ABA biosynthesis were up-regulated, while the transcripts of key enzymes for GAs biosynthesis were down-regulated. On the other hand, chlorophyll a and chlorophyll b contents were both increased compared with the control. Moreover, the net photosynthetic rate was elevated to 25.6 μmol CO2/m(2)/s compared with the control value of 22.05 μmol CO2/m(2)/s. Importantly, the expression of some chlorophyll biosynthesis-related transcripts was up-regulated.
  
  
  CONCLUSIONS
  Uniconazole treatment altered endogenous hormone levels and enhanced chlorophyll content and net photosynthetic rate in duckweed by regulating key enzymes involved in endogenous hormone and chlorophyll biosynthesis. The alterations of endogenous hormones and the increase of chlorophyll and photosynthetic rate data support the increase of biomass and starch accumulation.
authors: Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, 610041 China.|University of Chinese Academy of Sciences, Beijing, 100049 China.|Key Laboratory of Environmental and Applied Microbiology, Chinese Academy of Sciences, Chengdu, 610041 China.|Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu, 610041 China.
authors: Yang
authors: Y
authors: Liu
authors: Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, 610041 China.|Key Laboratory of Environmental and Applied Microbiology, Chinese Academy of Sciences, Chengdu, 610041 China.|Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu, 610041 China.
authors: Yang
authors: Y
authors: Fang
authors: Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, 610041 China.|University of Chinese Academy of Sciences, Beijing, 100049 China.|Key Laboratory of Environmental and Applied Microbiology, Chinese Academy of Sciences, Chengdu, 610041 China.|Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu, 610041 China.
authors: Mengjun
authors: M
authors: Huang
authors: Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, 610041 China.|Key Laboratory of Environmental and Applied Microbiology, Chinese Academy of Sciences, Chengdu, 610041 China.|Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu, 610041 China.
authors: Yanling
authors: Y
authors: Jin
authors: Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, 610041 China.|Key Laboratory of Environmental and Applied Microbiology, Chinese Academy of Sciences, Chengdu, 610041 China.|Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu, 610041 China.
authors: Jiaolong
authors: J
authors: Sun
authors: Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, 610041 China.|Key Laboratory of Environmental and Applied Microbiology, Chinese Academy of Sciences, Chengdu, 610041 China.|Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu, 610041 China.
authors: Xiang
authors: X
authors: Tao
authors: Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, 610041 China.|Key Laboratory of Environmental and Applied Microbiology, Chinese Academy of Sciences, Chengdu, 610041 China.|Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu, 610041 China.
authors: Guohua
authors: G
authors: Zhang
authors: Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, 610041 China.|Key Laboratory of Environmental and Applied Microbiology, Chinese Academy of Sciences, Chengdu, 610041 China.|Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu, 610041 China.
authors: Kaize
authors: K
authors: He
authors: Key Laboratory of Bio-Resources and Eco-Environment, Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610064 China.
authors: Yun
authors: Y
authors: Zhao
authors: Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, 610041 China.|Key Laboratory of Environmental and Applied Microbiology, Chinese Academy of Sciences, Chengdu, 610041 China.|Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu, 610041 China.
authors: Hai
authors: H
authors: Zhao
keywords: Chlorophyll; Endogenous hormones; Pathway; Photosynthetic rate; Uniconazole