Dinan L, Savchenko T, Whiting P
Department of Biological Sciences, University of Exeter, Devon, United Kingdom.
Cell Mol Life Sci. 2001 Jul;58(8):1121-32. doi: 10.1007/PL00000926.
The occurrence and levels of phytoecdysteroids in the seeds and other parts of plants grown from the seeds of 180 randomly selected plant species were assessed and compared. Ecdysteroids are frequently detectable in leaves and flowers, but less so in stems, roots and seeds. The seeds of 290 species were assessed for the presence of hydrolysable ecdysteroid conjugates. Low levels of conjugates were detected in a significant number of species, large amounts being present only when levels of free ecdysteroids were high. Individual plants of Arabidopsis thaliana were assessed for the presence of phytoecdysteroids. While plants of this species are generally ecdysteroid negative, individual plants in the population accumulate low levels of ecdysteroids. Extracts of seeds of 50 "ecdysteroid-negative" species were concentrated and partially purified to determine if they possess ecdysteroids at levels below the usual detection levels. Ecdysteroids were detectable by radioimmunoassay in almost all of these concentrated samples. Thus, all lines of evidence point to the conclusion that all species of plants have the capacity to produce at least low levels of phytoecdysteroids. This has important implications for the protection of crop species through enhancing ecdysteroid levels by breeding/genetic modification strategies.
对180种随机选择的植物种子及其生长出的植株的其他部位中植物蜕皮甾体的出现情况和含量水平进行了评估和比较。蜕皮甾体在叶片和花朵中常常可以检测到，但在茎、根和种子中则较少。对290种植物的种子进行了可水解蜕皮甾体缀合物的检测。在相当数量的物种中检测到了低水平的缀合物，只有当游离蜕皮甾体水平较高时才会有大量存在。对拟南芥的单株植物进行了植物蜕皮甾体的检测。虽然该物种的植物通常蜕皮甾体呈阴性，但群体中的单株植物会积累低水平的蜕皮甾体。对50种“蜕皮甾体阴性”物种的种子提取物进行浓缩和部分纯化，以确定它们是否含有低于通常检测水平的蜕皮甾体。通过放射免疫测定法在几乎所有这些浓缩样品中都检测到了蜕皮甾体。因此，所有证据都指向一个结论，即所有植物物种都有能力产生至少低水平的植物蜕皮甾体。这对于通过育种/基因改造策略提高蜕皮甾体水平来保护作物物种具有重要意义。
