Garnett Trevor, Conn Vanessa, Kaiser Brent N
School of Agriculture Food and Wine, The University of Adelaide, Urrbrae, SA 5064, Australia.
Plant Cell Environ. 2009 Sep;32(9):1272-83. doi: 10.1111/j.1365-3040.2009.02011.x. Epub 2009 Jun 10.
In the majority of agricultural growing regions, crop production is highly dependent on the supply of exogenous nitrogen (N) fertilizers. Traditionally, this dependency and the use of N-fertilizers to restore N depleted soils has been rewarded with increased plant health and yields. In recent years, increased competition for non-renewable fossil fuel reserves has directly elevated prices of N-fertilizers and the cost of agricultural production worldwide. Furthermore, N-fertilizer based pollution is becoming a serious issue for many regions where agriculture is highly concentrated. To help minimize the N footprint associated with agricultural production there is significant interest at the plant level to develop technologies which can allow economically viable production while using less applied N. To complement recent reviews examining N utilization efficiency in agricultural plants, this review will explore those strategies operating specifically at the root level, which may directly contribute to improved N use efficiencies in agricultural crops such as cereals, where the majority of N-fertilizers are used and lost to the environment. Root specific phenotypes that will be addressed in the context of improvements to N acquisition and assimilation efficiencies include: root morphology; root to shoot ratios; root vigour, root length density; and root N transport and metabolism.
在大多数农业种植区，作物生产高度依赖外源氮肥的供应。传统上，这种依赖性以及使用氮肥来恢复氮素亏缺的土壤，带来了作物健康状况改善和产量增加的结果。近年来，对不可再生化石燃料储备的竞争加剧，直接导致了全球范围内氮肥价格上涨和农业生产成本增加。此外，基于氮肥的污染正成为许多农业高度集中地区的一个严重问题。为了帮助最大限度地减少与农业生产相关的氮足迹，在植物层面上，人们对开发能够在减少氮肥施用量的情况下实现经济可行生产的技术有着浓厚兴趣。为补充近期有关农业植物氮利用效率的综述，本综述将探讨那些专门在根系层面发挥作用的策略，这些策略可能直接有助于提高诸如谷物等农作物的氮利用效率，在这些作物中，大部分氮肥被使用并流失到环境中。在改善氮素获取和同化效率的背景下将探讨的根系特定表型包括：根形态；根冠比；根活力、根长密度；以及根系氮素运输和代谢。
