Abstract：
Plant phenotypic plasticity plays an important role in nitrogen (N) acquisition and use under nitrogen-limited conditions. However, this role has never been quantified as a function of N availability, leaving it unclear whether plastic responses should be considered as potential targets for selection. A combined modelling and experimentation approach was adopted to quantify the role of plasticity on N uptake and plant yield. Based on a greenhouse experiment we considered plasticity in two maize traits: root-to-leaf biomass allocation ratio and emergence rate of axial roots. In a simulation experiment we individually enabled or disabled both plastic responses for maize stands grown across six N levels. Both plastic responses contributed to maintaining a higher N uptake and plant productivity as N-availability declined, compared to stands in which plastic responses were disabled. We conclude that plastic responses quantified in this study may be a potential target trait in breeding programs for greater N uptake across N levels while it may only be important for the internal use of N under N-limited conditions in maize. Given the complexity of breeding for plastic responses, an a priori model analysis is useful to identify which plastic traits to target for enhanced plant performance.
摘要：
在氮限制条件下，植物表型可塑性在氮（N）的获取和利用中起着重要作用。然而,这个角色从未被量化为N可用性的函数，尚不清楚塑性反应是否应被视为选择的潜在目标。采用建模和实验相结合的方法来量化可塑性对氮素吸收和植物产量的作用。根据温室实验，我们考虑了两个玉米性状的可塑性：根到叶的生物量分配率和轴根的出苗率。在模拟实验中，我们分别启用或禁用了在六个氮水平上生长的玉米林分的两种塑性响应。随着氮素可用性的下降，两种塑性反应都有助于保持较高的氮素吸收和植物生产力。与塑料反应被禁用的展台相比。我们得出的结论是，在这项研究中量化的塑性响应可能是育种计划中的潜在目标性状，可以在N水平上吸收更多的N，而它可能仅对玉米中N受限条件下N的内部使用很重要。考虑到塑料反应育种的复杂性，一个先验模型分析是有用的，以确定哪些塑料性状为目标，以提高植物的性能。
