N-fertilization has different effects on the growth, carbon and nitrogen physiology, and wood properties of slow- and fast-growing Populus species

Abstract

To investigate how N-fertilization affects the growth, carbon and nitrogen (N) physiology, and wood properties of poplars with contrasting growth characteristics, slow-growing (Populus popularis, Pp) and fast-growing (P. alba×P. glandulosa, Pg) poplar saplings were exposed to different N levels. Above-ground biomass, leaf area, photosynthetic rates (A), instantaneous photosynthetic nitrogen use efficiency (PNUE i), chlorophyll and foliar sugar concentrations were higher in Pg than in Pp. Foliar nitrate reductase (NR) activities and root glutamate synthase (GOGAT) activities were higher in Pg than in Pp as were the N amount and NUE of new shoots. Lignin contents and calorific values of Pg wood were less than that of Pp wood. N-fertilization reduced root biomass of Pg more than of Pp, but increased leaf biomass, leaf area, A, and PNUEi of Pg more than of Pp. Among 13 genes involved in the transport of ammonium or nitrate or in N assimilation, transcripts showed more pronounced changes to N-fertilization in Pg than in Pp. Increases in NR activities and N contents due to N-fertilization were larger in Pg than in Pp. In both species, N-fertilization resulted in lower calorific values as well as shorter and wider vessel elements/fibres. These results suggest that growth, carbon and N physiology, and wood properties are more sensitive to increasing N availability in fast-growing poplars than in slow-growing ones, which is probably due to prioritized resource allocation to the leaves and accelerated N physiological processes in fast-growing poplars under higher N levels.

The Effects of Fertilization on the Growth and Physiological Characteristics of Ginkgo biloba L.

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A Transcriptomic Network Underlies Microstructural and Physiological Responses to Cadmium in Populus × canescens

“…NRT2;4 is a plasma membrane nitrate transporter that is expressed in shoot phloem in response to external nitrogen concentrations (Kiba et al, 2012;Li et al, 2012). Phosphate transporters (PHT1;4 and PHT3;3) are involved in phosphorus signaling and transport in Arabidopsis (Morcuende et al, 2007;Lei et al, 2011).…”

“…Quantitative reverse transcription (RT)-PCR of seven genes (for primer information, see Supplemental Table S8) was performed according to Li et al (2012). The reference gene was 18S ribosomal RNA (Supplemental Table S8).…”

Effects of nitrogen and phosphorus supply on growth and physiological traits of two Larix species

“…The fast-growing ones possess greater N and P use efficiencies and higher enzymatic activities related to N assimilation and P mobilization (Gan et al, 2015). The fast-growing broadleaved tree Populus alba  P. glandulosa is more sensitive to increasing N availability (Li et al, 2012), while the slowly growing P. popularis is more sensitive to decreasing N availability (Luo et al, 2013b). Also, fast growing P. deltoides females are more sensitive to inorganic nitrogen forms than the slow growing male trees .…”