光合细菌对Cd~(2+)胁迫下黑小麦幼苗生长及抗氧化酶的影响

采用水培试验方法系统研究了不同浓度Cd^2＋、不同形式光合细菌及光合细菌与Cd^2＋协同处理对黑小麦种子萌发、幼苗生长及抗氧化酶的影响，以探讨光合细菌对植物幼苗生长及应激能力的影响。结果表明：低浓度Cd^2＋对幼苗生长具有轻微刺激作用，高浓度Cd^2＋对幼苗生长具有抑制作用；光合细菌菌体及30倍稀释上清液对种子萌发及幼苗生长具有刺激作用，而培养液原液及上清液具有显著抑制作用；不同处理均可引起黑小麦POD及CAT酶活性及同工酶表达的改变；外部形态及内源抗氧化酶改变均表明光合细菌对Cd^2＋胁迫伤害黑小麦幼苗具有一定缓解效应。

Effects of Photosynthetic Bacteria on Seedling Growth and Antioxidant Enzymes in Black Wheat Under Cadmium Stress

The seeds of black wheat were cultured in liquid media containing heavy metal Cd2 ,photosynthetic bacteria(Rhodopseudomonas palustris)or the combination of both.The seed germination,seedling growth and antioxidant enzyme activities were examined for each media,in order to explore the possible facilitative effects of photosynthetic bacteria on early-stage growth and development of black wheat.The data showed that low amount of Cd2 could slightly stimulate the seedling growth,but high concentration of Cd2 had inhibition effects.The photosynthetic bacteria colonies and the culture supernatant diluted by 30 times significantly improved the seed germination rate and seedling growth,but the undiluted culture solution or its supernatants showed deterring effects.The POD and CAT activities of seedlings changed when exposed to Cd2 and/or bacterial culture solutions.The morphological improvement and the enhancement of the antioxidant enzyme activity in black wheat seedlings suggested that the photosynthetic bacteria could alleviate the damage caused by Cd2 stress.