The response of the maize nitrate transport system to nitrogen demand and supply across the lifecycle
The response of the maize nitrate transport system to nitrogen demand and supply across the lifecycle
复制标题
DOI：
10.1111/nph.12166
复制
发表时间：
2013-04-01
期刊：
影响因子：
9.4
通讯作者：
Kaiser, Brent N.
中科院分区：
文献类型：
--
作者：
Garnett, Trevor;Conn, Vanessa;Kaiser, Brent N.
了解植物在整个生命周期中对硝酸盐（NO3）的吸收，以及这一过程如何响应氮（N）的可用性，是开发具有提高氮利用效率（NUE）的植物的重要一步。NO3吸收能力和转录水平的推定的高和低亲和力NO3转运蛋白（NRT）的分布在整个生命周期的矮秆玉米（玉米）植物生长在减少和足够的NO3。植物在整个生命周期中表现出高亲和力NO3吸收能力的重大变化，这与根和芽的相对生长速率的变化。假定的高亲和力NRT（主要是ZmNRT2.1和ZmNRT2.2）的转录本丰度与高亲和力根NO3吸收能力和N可用性的两个不同的峰值相关。在生命周期中NO3供应的减少导致NO3吸收能力的急剧增加，这之前的NRT的转录水平的变化，这表明一个模型与短期的翻译后调节和长期的转录调节NO3吸收能力。这些观测结果提供了新的见解控制NO3吸收的植物发育过程和N的可用性，并确定关键的控制点，可能是有针对性的未来植物改良计划，以提高N的吸收相对于可用性和/或需求。
An understanding of nitrate (NO3 ) uptake throughout the lifecycle of plants, and how this process responds to nitrogen (N) availability, is an important step towards the development of plants with improved nitrogen use efficiency (NUE). NO3 uptake capacity and transcript levels of putative high- and low-affinity NO3 transporters (NRTs) were profiled across the lifecycle of dwarf maize (Zea mays) plants grown at reduced and adequate NO3 . Plants showed major changes in high-affinity NO3 uptake capacity across the lifecycle, which varied with changing relative growth rates of roots and shoots. Transcript abundances of putative high-affinity NRTs (predominantly ZmNRT2.1 and ZmNRT2.2) were correlated with two distinct peaks in high-affinity root NO3 uptake capacity and also N availability. The reduction in NO3 supply during the lifecycle led to a dramatic increase in NO3 uptake capacity, which preceded changes in transcript levels of NRTs, suggesting a model with short-term post-translational regulation and longer term transcriptional regulation of NO3 uptake capacity. These observations offer new insight into the control of NO3 uptake by both plant developmental processes and N availability, and identify key control points that may be targeted by future plant improvement programmes to enhance N uptake relative to availability and/or demand.