The Role of Endoreduplication in Mitigating the Detrimental Effects of Herbivory

内复制是指在没有有丝分裂的情况下复制基因组，从而导致内多倍体，即细胞染色体数量的增加。内复制过程几乎存在于所有草本植物中，但其主要功能尚不清楚。在这里，佩奇博士提议测试一个新的想法--染色体扩增可以减轻食草动物的有害影响，促进生长和繁殖。Paige实验室之前的研究表明，染色体扩增、植物繁殖和食草动物之间存在相关性，然而，还没有建立直接的因果联系。为了建立因果关系，他将利用一套温室和田间研究来推广两种植物--拟南芥和拟南芥--的这种现象，评估调节染色体扩增的基因ILP1是否与拟南芥在草食后的繁殖成功有关，并使用ILP1的敲除和过表达突变体来建立染色体扩增、草食和生殖成功之间的因果关系。如果染色体扩增导致繁殖增强，这种变化可能具有适应性，并在植物中普遍存在，以减轻草食的有害影响。此外，了解食草动物危害后种子产量增加的遗传基础应该引起农学家的极大兴趣，他们通过最近的基因技术的进步，可能会将一些性状(如ILP1过度表达启动子)整合到作物中，如油菜(Brassica Napus)，它是拟南芥的近亲，也可以扩大染色体数量。他还怀疑，这些研究远远超出了植物和食草动物之间的相互作用，实际上可能代表了对各种环境应激源的普遍反应。

Endoreduplication is the replication of the genome without mitosis, which leads to endopolyploidy, an increase in cellular chromosome number. The process of endoreduplication occurs in nearly all herbaceous flowering plants, yet its primary function is unknown. Here Dr. Paige proposes to test a novel idea - that chromosome amplification can mitigate the detrimental effects of herbivory and lead to enhanced growth and reproduction. Previous studies by the Paige lab have shown a correlation between chromosome amplification, plant reproduction and herbivory, however, no direct causal links have been established. To establish a causal relationship he will use a suite of greenhouse and field studies to generalize the phenomenon within two species of plants, Arabidopsis thaliana and Ipomopsis aggregata, assess whether ILP1, a gene that regulates chromosome amplification, correlates with reproductive success following herbivory in A. thaliana and use knockout and overexpression mutants of ILP1 to establish a causal relationship between chromosome amplification, herbivory and reproductive success.If chromosome amplification leads to enhanced reproduction, such changes may be of an adaptive nature and widespread among plants in mitigating the detrimental effects of herbivory. Furthermore, gaining an understanding of the genetic basis of increased seed yield following herbivore damage should be of great interest to agriculturists who, through recent advents in genetic technology, might incorporate traits (such as ILP1 overexpression promoters) into crop plants such as oilseed rape (Brassica napus), a close relative of Arabidopsis that also amplifies chromosome number. He also suspects that these studies reach far beyond the interactions between plants and herbivores and may in fact represent a generalized response to all kinds of environmental stressors.