[Dose-response relationships between endogenous phytohormones of high plant and concentrations of fluoranthene and benzo(a)pyrene in soils].

By means of indoor pot experiment, three phytohormones, gibberellic acid (GA3), zeatin and zeatin riboside (Z&ZR), abscisic acid (ABA) of wheat ( Triticum acstivnm) were measured under the stress of fluoranthene and benzo(a)pyrene in meadow brown soil singlely and combinedly. The results indicated that significant dose-response relationship was observed between ABA contents and the concentrations of single fluoranthene and combined pollution of fluoranthene and benzo(a)pyrene, and ABA content responded more intensive to single fluoranthene than to combined treatment. When treated with 16 mg x kg(-1) single fluoranthene, ABA content increased by 198% as compared with control. Significant effects on GA3 content of combined treatment were also observed, but GA3 responded insensitively to single fluoranthene and benzo(a)pyrene treatment. Z&ZR responded intensively under stress of both single and combined pollution, and the inducible effects were accordant. It can be concluded that endogenous phytohormones play an important role in indicating PAHs polluted soil, and the sensitivity of the three phytohormones responded to fluoranthene and benzo(a)pyrene single and combined pollution is in the sequence: Z&ZR > ABA > GA3.