DISSERTATION RESEARCH: Does Herbivory Signal Plants to Increase Nitrogen Uptake and Bolster Nitrogen and Starch Storage?

当植物受到咀嚼叶子的食草动物的攻击时，它们必须科普叶子组织的损失，叶子组织含有丰富的植物营养物质，对于从阳光中获取生长所需的能量非常重要。 植物可以将一些能量和营养物质储存在更坚硬的组织中，例如许多食草动物不能轻易食用的茎和根。 淀粉和蛋白质是植物中最常见的贮藏化合物。 在最近的研究中，放射性碳的使用使得可以研究活植物中的分配过程。 一项这样的研究表明，植物可能会增加储存响应草食动物。 茉莉酸（JA）是植物识别植食性天敌的重要信号分子，在杨树和白杨幼苗中，JA增加了放射性碳向下部茎和根的运输量。 这里提出的研究将确定JA和昆虫植食性是否会导致茎和根中储存化合物的增加以及杨树和白杨根的营养摄入量增加。 将利用对植物重要的元素的放射性同位素（碳-11、氮-13）研究活植物的短期过程。 将使用稳定同位素（碳-13、氮-15）和化学分析来检查储存化合物的长期积累情况。 食草动物咀嚼叶片后，氮吸收增加，碳和氮储存化合物的积累增加，表明植物可以调整其代谢，以最大限度地提高其在叶片损失和损害中的生存能力，并改善其再生长。 这项对草食动物信号的储存调节的开创性研究对于理解植物如何进化以科普草食动物是必要的。 此外，对植物如何耐受损害的更好理解可能会影响商业农业和林业实践，并可能产生操纵植物以改善生存和生长的见解。

When plants are attacked by leaf-chewing herbivores, they must cope with the loss of leaf tissues, which hold an abundance of the plant's nutrients and are important for capturing energy from sunlight for growth. Plants can store some of their energy and nutrients in tougher tissues, such as stems and roots that many herbivores cannot eat as readily. Starch and proteins are the most common storage compounds in plants. The use of radioactive carbon in recent research has allowed the study of allocation processes in living plants. One such study indicates that plants might increase storage in response to herbivory. An important signal molecule, jasmonic acid (JA), involved in plant recognition of herbivore attack increased the amount of radioactive carbon transported to the lower stem and roots in poplar and aspen tree saplings. The research proposed here will determine whether JA and insect herbivory cause increases in storage compounds in the stem and roots and increased nutrient intake by the roots of poplars and aspens. Short-term processes will be studied in living plants using radioactive isotopes of elements important to plants (carbon-11, nitrogen-13). The longer-term build-up of storage compounds will be examined using stable isotopes (carbon-13, nitrogen-15) and chemical analysis. Increased nitrogen uptake and increased build-up of carbon and nitrogen storage compounds following the initiation of herbivore leaf-chewing would indicate that plants can adjust their metabolism to maximize their ability to survive leaf loss and damage and to improve their re-growth. This pioneering research of storage regulation in response to herbivore signals will be necessary to understand how plants have evolved to cope with herbivory. Moreover, an improved understanding of how plants tolerate damage may influence commercial agricultural and forestry practices, and could generate insights for manipulating plants to improve survival and growth.