高等植物内源激素与土壤荧蒽、苯并(a)芘污染诱导的剂量-效应关系

Dose-Response Relationships Between Endogenous Phytohormones of High Plant and Concentrations of Fluoranthene and Benzo(a)pyrene in Soils

以小麦(Triticum acstivnm)为供试植物,草甸棕壤为供试土壤,采用室内培养箱盆栽方法,研究了荧蒽、苯并(a)芘单一及复合污染胁迫与小麦叶片中3种植物内源激素赤霉素(gibberellic acid,GA3)、细胞分裂素类的玉米素及玉米素核苷总量(zeatinand zeatin riboside,Z&ZR)、脱落酸(abscisic acid,ABA)的污染诱导剂量-效应关系.结果表明,荧蒽单一及与苯并(a)芘复合污染胁迫对小麦体内ABA的合成有明显的诱导作用,并且荧蒽单一污染的诱导作用较强,当荧蒽浓度为16 mg.kg-1时,ABA含量比对照增加了198%.荧蒽、苯并(a)芘复合污染对GA3的合成表现为明显的诱导抑制效应,而GA3对单一污染胁迫响应趋势不明显.荧蒽、苯并(a)芘单一及复合污染胁迫对Z&ZR的合成均产生明显的诱导抑制效应.本研究表明,3种内源激素对土壤低剂量多环芳烃污染指示具有重要作用,其对荧蒽、苯并(a)芘单一及复合污染响应的敏感性顺序为:Z&ZR>ABA>GA3.

By means of indoor pot experiment, three phytohormones, gibberellic acid （GA3）, zeatin and zeatin fiboside （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@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 〉 GAs .