Molecular mechanism for cadmium-induced anthocyanin accumulation in Azolla imbricata.
Anthocyanins inducibly synthesized by Cd treatment showed high antioxidant activity and might be involved in internal detoxification mechanisms of Azolla imbricata against Cd toxicity. In order to understand anthocyanin biosynthesis mechanism during Cd stress, the cDNAs encoding chalcone synthase (CHS) and dihydroflavonol reductase (DFR), two key enzymes in the anthocyanin synthesis pathway, were isolated from A. imbricata. Deduced amino acid sequences of the cDNAs showed high homology to the sequences from other plants. Expression of AiDFR, and to a lesser extent AiCHS, was significantly induced in Cd treatment plant in comparison with the control. CHS and DFR enzymatic activities showed similar pattern changes with these genes expression during Cd stress. These results strongly indicate that Cd induced anthocyanin accumulation is probably mediated by up-regulation of structural genes including CHS and DFR, which might further increase the activities of enzymes encoded by these structural genes that control the anthocyanin biosynthetic steps.
School of Life and Environmental Science, Wenzhou University, Wenzhou 325035, China. lpdai825@126.com
Ling-Peng
LP
Dai
Xin-Jiao
XJ
Dong
Hai-Hu
HH
Ma
D000429:Alcohol Oxidoreductases / Q000235:genetics / Q000378:metabolism; D000595:Amino Acid Sequence; D000872:Anthocyanins / Q000096:biosynthesis*; D002104:Cadmium / Q000633:toxicity*; D029624:Ferns / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D015870:Gene Expression / Q000187:drug effects; D008969:Molecular Sequence Data; D012989:Soil Pollutants / Q000633:toxicity*
D000872:Anthocyanins; D012989:Soil Pollutants; D002104:Cadmium; D000429:Alcohol Oxidoreductases; C093070:chalcone reductase; C056570:dihydroflavanol 4-reductase