脯氨酸对不结球白菜（Brassica chinensis）镉积累的影响

采用溶液培养的方法,研究了过量Cd对不结球白菜（Brassica chinensis）幼苗内源脯氨酸含量的影响及外源脯氨酸在不结球白菜Cd积累中的作用。100μmol？L-1 Cd处理明显增加不结球白菜叶片脯氨酸（Pro）的含量,并且随着Cd胁迫时间的延长,其含量也显著上升。100μmol？L-1 Cd处理明显降低脯氨酸脱氢酶（PDH）活性,而增加δ1-吡咯啉-5-羧酸合成酶（P5CS）的活性。1~5 mmol？L-1外源Pro处理显著降低不结球白菜幼苗地上部Cd含量,对根系Cd含量无显著影响,但外源Pro处理并不能缓解过量Cd对不结球白菜幼苗生物量的抑制作用。外源Pro处理下,不结球白菜叶片中Pro含量与其地上部干重呈显著的负相关关系。

Effects of Proline on Cadmium Accumulation in Brassica chinensis

Hydroponic experiments were used to study the effects of cadmium on endogenous proline content in Brassica chinensis seedlings and the roles of exogenous proline on cadmium accumulation in plants were also studied. The contents of proline in leaves of B. chinensis were significantly increased under 100μmol·L^-1 Cd treatment, and accumulated more as the stress prolonged. The activities of PDH were significantly decreased under 100 μmol·L^-1 Cd treatment, while P5CS increased. Exposure with 1-5 mmol·L^-1 proline significantly decreased the Cd concentrations in the shoots orB. chinensis seedlings, and had no effect on the Cd concentration in roots. However, exogenous proline had no alleviation effect on biomass ofB. chinensis seedlings treated with Cd. A negative correlation between the contents ofproline in leaves ofB. chinensis and the dry weight of shoots was found under exogenous proline stress.