J Plant Ecol ›› 2019, Vol. 12 ›› Issue (2): 235-244.

• Research Articles •

### Nitrogen preference across generations under changing ammonium nitrate ratios

Stefani Daryanto1,2, Lixin Wang1,*, William P. Gilhooly III1 and Pierre-André Jacinthe1#br#

1. 1 Department of Earth Sciences, Indiana University Purdue University Indianapolis, Indianapolis, IN 46202, USA
2 State Key Laboratory of Earth Surface Processes and Resource Ecology, Faculty of Geographical Science, Beijing Normal University, Beijing 100875, China
*Correspondence address. Department of Earth Sciences, Indiana University Purdue University, 723 W. Michigan St., Indianapolis, IN 46202, USA. Tel: +317-274-7764; Fax: +317-274-7966; E-mail: lxwang@iupui.edu
• Received:2017-11-02 Revised:2018-01-22 Accepted:2018-03-29 Online:2018-03-31 Published:2019-04-01

Abstract:

Aims

Nitrogen (N) in natural environments is typically supplied by a mixture of ammonia (NH4+) and nitrate (NO3-). However, factors that underlie either NH4+ or NO3- preference, and how such preference will change across generations remain unclear. We conducted a series of experiments to answer whether: (i) NH4+:NO3- ratio is the driving factor for plant N preference, and (ii) this preference is consistent across generations.

Methods

We conducted both: (i) field observations (as a proxy for parent or P generation) and (ii) greenhouse experiments (the first generation or F1 and the second generation or F2) using corn and soybean grown under different NH4+:NO3- ratios.

Important Findings

Both corn and soybean had the physiological plasticity to prefer either NH4+ or NO3- depending on NH4+:NO3- ratios, and this plasticity was consistent across generations. Corn, however, showed a stronger preference towards NO3- while soybean showed a stronger preference towards NH4+. While both plants would try to make use of the most available form of N in their growing medium, plant species, physiological characteristics (e.g. maturity) and plant nutrient status also determined the extent of N uptake. From the evolutionary and productivity perspective, this plasticity is beneficial, allowing plants to effectively acquire available N particularly in a changing climate.