MECHANISM OF DAMAGE-INDUCED ALKALOID PRODUCTION IN WILD TOBACCO
MECHANISM OF DAMAGE-INDUCED ALKALOID PRODUCTION IN WILD TOBACCO
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DOI：
10.1007/bf01012392
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发表时间：
1989-05-01
影响因子：
2.3
通讯作者：
BALDWIN, IT
中科院分区：
文献类型：
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作者：
BALDWIN, IT
受到叶损伤的温室生长的种Nicotiana sylvestris（茄科）烟草植物显示其未损伤叶的生物碱含量增加四倍。尼古丁和去甲尼古丁浓度的增加开始后19小时结束的损害制度，达到最大值在9天，并减弱到控制水平后14天开始的叶损害。在受损的植物叶生物碱含量的增加主要是由于进入叶，这反过来又表明，增加的生物碱合成的木质部流体的生物碱浓度增加了10倍。本研究区分影响木质部流体生物碱浓度变化的积极和消极线索。一个负面的线索，如生长素，当失去或减少作为一个结果，叶损伤可能信号的拟南芥的反应。事实上，外源应用生长素受损叶片抑制生物碱的反应。然而，试图阻止内源性生长素运输蒸汽环剥或应用生长素运输抑制剂未能模仿叶损伤对叶生物碱浓度的影响。损害线索似乎是一个积极的线索，是有关的时间和数量的叶片损害，而不是数量的叶质量损失。此外，当进行近端叶损伤，蒸汽环剥截断的nestidal响应。这种诱导的杀线虫反应似乎是由韧皮部传播的线索触发的，该线索允许植物区分不同类型的叶损伤。进一步探讨了这种损伤诱导的杀虫反应机制的生理和生态后果。
Greenhouse-grown tobacco plants of the species Nicotiana sylvestris (Solanaceae) subjected to leaf damage show a fourfold increase in the alkaloid content of their undamaged leaves. This increase in nicotine and nornicotine concentrations begins 19 hr after the end of the damage regime, reaches a maximum at nine days, and wanes to control levels 14 days after the start of leaf damage. The increase in leaf alkaloid content in damaged plants is largely due to a 10-fold increase in the alkaloid concentration of the xylem fluid entering leaves, which, in turn, suggests that increased synthesis of alkaloids is occurring in the roots. This research distinguishes between positive and negative cues affecting the change in xylem fluid alkaloid concentrations. A negative cue, such as auxin, when lost or diminished as a result of leaf damage could signal the alkaloidal response. Indeed, exogenous applications of auxin to damaged leaves inhibit the alkaloid response. However, attempts to block endogenous auxin transport by steam girdling or applying an auxin transport inhibitor fail to mimic the effect of leaf damage on leaf alkaloid concentrations. The damage cue appears to be a positive cue that is related to the timing and the amount of leaf damage rather than to the amount of leaf mass lost. Moreover, when performed proximally to leaf damage, steam girdling truncates the alkaloidal response. This induced alkaloidal response appears to be triggered by a phloem-borne cue that allows the plant to distinguish between different types of leaf damage. The physiological and ecological consequences of the mechanism of this damage-induced alkaloidal response are further explored.