Analysis of Flavonoid Contents and Expression of Flavonoid Biosynthetic Genes in Populus euramericana Guinier in Response to Abiotic Stress

Gene encoding the key flavonoid biosynthetic enzyme, chalcone synthase, in Poplin's euramericana Guinier (PeCHS) was cloned and characterized. PeCHS preferentially uses feniloyl-CoA as a substrate. Expression of the flavonoid biosynthetic genes, phenylalanine ammonimum lyase from P euramericana (PePAL), PeCHS, chalcone isomerase from P euramericana (PeCHI), and flavonol synthase from P euramericana (PeFLS) from P euramericana in response to abiotic stresses such as wounding and UV-irradiation were analyzed. These genes were induced under the stress conditions. Most genes were expressed at an early stage of the stress response. In addition, total flavonoid content increased after UV-irradiation.