Siegwolf RTW, Matyssek R, Saurer M, Maurer S, Günthardt-Goerg MS, Schmutz P, Bucher JB. Stable isotope analysis reveals differential effects of soil nitrogen and nitrogen dioxide on the water use efficiency in hybrid poplar leaves.
THE NEW PHYTOLOGIST 2001;
149:233-246. [PMID:
33874623 DOI:
10.1046/j.1469-8137.2001.00032.x]
[Citation(s) in RCA: 39] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
• The effects of nitrogen dioxide (NO2 ) exposure are reported on the physiology, morphology and carbon partitioning of hybrid poplar clone cuttings (Populus ×euramericana) grown under high and low soil nitrogen supply. • Plants were exposed to filtered air or NO2 -enriched air (80-135 nl l-1 ) over 12 wk growth in phytotrons. Stable isotope analysis, combined with CO2 and H2 O gas exchange measurements, biomass analysis and morphological development, was used to assess the integrated long-term effects of NO2 . • NO2 had no toxic effects. A reduced 15 N-isotope ratio indicated incorporation of NO2 while nitrate reductase activity in leaves was stimulated. The two nitrogen sources had differential effects on water use efficiency (WUE): NO2 exposure increased long-term WUE; soil N supply decreased WUE; a result not detectable using growth and short-term gas exchange experiments. Plants benefited from airborne NO2 , increasing CO2 assimilation rate and biomass; both N sources increased shoot production at the expense of root growth. NO2 exposure induced leaf formation with reduced stomatal density and increased leaf area. • NO2 exposure might be beneficial although the reduced root: shoot biomass could have a detrimental effect on nutrient balance and drought resistance.
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