【摘要】 在长日照条件下,10-7mol/L的二苯脲对紫萍半叶状体就有保绿的作用,10-5～2×10-4mol/L的二苯脲还可以明显地促进叶绿素的合成和干重的增加,提高丝氨酸乙醛酸转氨酶的活性,延缓半叶状体的衰老.实验结果表明,二苯脲本身具有细胞分裂素的活性,能代替内源细胞分裂素起到抗衰老的作用;二苯脲同时也能推迟半叶状体中内源细胞分裂素含量的降低.另外,在培养液中加入外源L-丝氨酸,可以抗拮二苯脲对紫萍半叶状体衰老的延缓作用,说明二苯脲抗衰老的机制类似于其它细胞分裂素.更多还原

【Abstract】 DPU at a concentration of as low as 10~-7 mol/L retained the chlorophyll of Spirodela half-fronds under long-day conditions. From 10~-5 ～2×10~-4 mol/L it prompted the synthesis of chlorophlly and the serine:glyoxylate aminotransferase (SGAT) activity, increased dry weight, and retarded the senescence of half-fronds. It was demonstrated that DPU itself acted as a kind of cytokinin in delaying senescence. However, it also postponed the decline of endogenous cytokinins of half-fronds. L-serine added into the medium (10~-3 mol/L) antagonized the effect of DPU, which shows the mechanism of DPU in delaying senescence is most likely similar to other cytokinins.$$$$更多还原