SNF1-related kinases allow plants to tolerate herbivory by allocating carbon to roots
SNF1-related kinases allow plants to tolerate herbivory by allocating carbon to roots
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DOI：
10.1073/pnas.0602316103
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发表时间：
2006-08-22
影响因子：
11.1
通讯作者：
Baldwin, Ian T.
中科院分区：
文献类型：
--
作者：
Schwachtje, Jens;Minchin, Peter E. H.;Baldwin, Ian T.
食草动物的攻击引发了代价高昂的防御措施，众所周知，这些防御措施会使用通常用于生长和繁殖的资源，从而降低植物的适应性。此外，植物已经进化出耐受攻击的机制，这在分子水平上还不清楚。利用C-11-光合作用标记以及糖和酶的测量，我们发现在模拟食草动物攻击后，一年一度的烟草的库源关系发生了迅速的变化，增加了糖向根的分配。这种由食草动物诱导的反应受SnRK1(SNF1相关激酶)蛋白激酶GAL83的β亚基调控，在食草动物攻击后，GAL83的转录本在源叶中迅速下调，当沉默时，增加同化物向根的运输。这种C转导反应是由食草动物特有的激发子激活的，不依赖于茉莉酸信号，茉莉酸信号调节植物的大部分防御反应。在发育的早期阶段，食草动物的攻击增加了根的储备，这反过来又延缓了衰老，延长了开花时间。这攻击了GAL83沉默的植物，利用它们增强的根储备来延长繁殖时间，这表明SnRK1改变了资源分配，使植物更好地耐受草食。这种容忍机制补充了将资源转移到工厂内较不脆弱的位置可能具有的防御价值。
Herbivore attack elicits costly defenses that are known to decrease plant fitness by using resources that are normally slated for growth and reproduction. Additionally, plants have evolved mechanisms for tolerating attack, which are not understood on a molecular level. Using C-11-photosynthate labeling as well as sugar and enzyme measurements, we found rapid changes in sink-source relations in the annual Nicotiana attenuata after simulated herbivore attacks, which increased the allocation of sugars to roots. This herbivore-induced response is regulated by the beta-subunit of an SnRK1 (SNF1-related kinase) protein kinase, GAL83, transcripts of which are rapidly down-regulated in source leaves after herbivore attack and, when silenced, increase assimilate transport to roots. This C diversion response is activated by herbivore-specific elicitors and is independent of jasmonate signaling, which regulates most of the plant's defense responses. Herbivore attack during early stages of development increases root reserves, which, in turn, delays senescence and prolongs flowering. That attacked GAL83-silenced plants use their enhanced root reserves to prolong reproduction demonstrates that SnRK1 alters resource allocation so that plants better tolerate herbivory. This tolerance mechanism complements the likely defensive value of diverting resources to a less vulnerable location within the plant.