More than a 600‐fold variation in nitrogen dioxide assimilation among 217 plant taxa

Abstract

Assimilation of nitrogen dioxide in response to fumigation with 15 N-labelled nitrogen dioxide was studied in 217 plant taxa. The taxa included 50 wild herbaceous plants collected from roadsides (42 genera, 15 families), 60 cultivated herbaceous plants (55 genera, 30 families) and 107 cultivated woody plants (74 genera, 45 families). Two parameters, the 'NO 2 -N content', or NO 2 -derived reduced nitrogen content in fumigated plant leaves (mg N g -1 dry weight), and the 'NO 2 -utilization index', or percentage of the NO 2 -derived reduced nitrogen in the total reduced nitrogen, were determined. The NO 2 -N content differed 657-fold between the highest (Eucalyptus viminalis; 6·57) and lowest (Tillandsia ionantha and T. caput-medusae; 0·01) values in the 217 taxa; 62-fold in a family (Theaceae) and 26-fold in a species (Solidago altissima). Nine species had NO 2 -utilization indices greater than 10%, of which Magnolia kobus, Eucalyptus viminalis, Populus nigra, Nicotiana tabacum and Erechtites hieracifolia had NO 2 -N contents > 4·9. These plants can be considered 'NO 2 -philic' because in them NO 2 -nitrogen has an important function(s). The Compositae and Myrtaceae had high values for both parameters, whereas the monocots and gymnosperms had low ones. These findings suggest that the metabolic pathway of NO 2 -nitrogen differs among plant species. The information presented here will be useful for creating a novel vegetation technology to reduce the atmospheric concentration of nitrogen dioxide.

Air-Pollutant-Philic Plants for Air Remediation

“…In the 217 taxa examined, the RNNO 2 value varied among the individuals of a species [16]. This variation was more pronounced in the wild herbaceous and woody plants than in the cultivated herbaceous plants.…”

“…Plants were fumigated in a fumigation chamber at 22˚C ± 0.3˚C, 70% ± 4% relative humidity, and an atmospheric level of 0.03% to 0.04% CO 2 15 N in the samples was determined using an EA-MS analyzer in which an elemental analyzer (EA/NA; Fisons Instruments, Milano, Italy) interfaced with a mass spectrometer (Delta C; Thermo Finnigan, Bremen, Germany), as described previously [16]. From these two values, total ( 14 N plus 15 N) nitrogen derived from NO 2 in the leaves of fumigated plants (mg N/g dry weight) was determined (designated TNNO 2 ).…”

“…Details of the data on 217 taxa have been published [16,19], and here we briefly discuss some points in relation to the air-pollutant-philic plants. [16].…”

“…Among wild herbaceous plants (19 individuals), the variation was 26.2-fold in Solidago altissima, 21.4-fold in Rumex acetosella, and 17.6-fold in Crassocephalum crepidioides. In woody plants, the corresponding value was 11.9-fold in M. kobus, 10.6-fold in Euonymus japonicus, and 6.7-fold in Prunus cerasoides [16]. Understanding differences among individuals of the same species in their abilities to assimilate NO 2 is also important in terms of genetically constructing air-pollutant-philic plants.…”

Genetic engineering of nitrite reductase gene improves uptake and assimilation of nitrogen dioxide by Rhaphiolepis umbellata (Thunb.) Makino

“…naturally occurring plants in the capability to assimilate NO 2 (Morikawa et al 1998), much higher improvement of the capability of this species may be needed. Innovation of new promoters for this woody species will be a plausible approach to address such issue.…”