Abstract
To investigate N metabolism of two contrasting Populus species in acclimation to low N availability, saplings of slow-growing species (Populus popularis, Pp) and a fast-growing species (Populus alba × Populus glandulosa, Pg) were exposed to 10, 100, or 1000 μM NH4NO3. Despite greater root biomass and fine root surface area in Pp, lower net influxes of NH4(+) and NO3(-) at the root surface were detected in Pp compared to those in Pg, corresponding well to lower NH4(+) and NO3(-) content and total N concentration in Pp roots. Meanwhile, higher stable N isotope composition (δ(15)N) in roots and stronger responsiveness of transcriptional regulation of 18 genes involved in N metabolism were found in roots and leaves of Pp compared to those of Pg. These results indicate that the N metabolism of Pp is more sensitive to decreasing N availability than that of Pg. In both species, low N treatments decreased net influxes of NH4(+) and NO3(-), root NH4(+) and foliar NO3(-) content, root NR activities, total N concentration in roots and leaves, and transcript levels of most ammonium (AMTs) and nitrate (NRTs) transporter genes in leaves and genes involved in N assimilation in roots and leaves. Low N availability increased fine root surface area, foliar starch concentration, δ(15)N in roots and leaves, and transcript abundance of several AMTs (e.g. AMT1;2) and NRTs (e.g. NRT1;2 and NRT2;4B) in roots of both species. These data indicate that poplar species slow down processes of N acquisition and assimilation in acclimation to limiting N supply.
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Claims 12
Claim · model-written summary
Pp had greater root biomass and fine root surface area than Pg.
Verbatim
e0“greater root biomass and fine root surface area in Pp”
e1“slow-growing species (Populus popularis, Pp) and a fast-growing species (Populus alba × Populus glandulosa, Pg)”
Claim · model-written summary
Pp had lower root surface influxes of ammonium and nitrate than Pg.
Verbatim
e0“lower net influxes of NH4(+) and NO3(-) at the root surface were detected in Pp compared to those in Pg”
e1“Populus popularis, Pp”
e2“Populus alba × Populus glandulosa, Pg”
Claim · model-written summary
Pp roots had lower ammonium, nitrate and total nitrogen than Pg.
Verbatim
e0“lower NH4(+) and NO3(-) content and total N concentration in Pp roots”
e1“Populus popularis, Pp”
Claim · model-written summary
Pp roots had higher stable nitrogen isotope composition than Pg.
Verbatim
e0“higher stable N isotope composition (δ(15)N) in roots”
e1“Populus popularis, Pp”
Claim · model-written summary
Pp showed stronger transcriptional response of 18 nitrogen metabolism genes than Pg.
Verbatim
e0“stronger responsiveness of transcriptional regulation of 18 genes involved in N metabolism were found in roots and leaves of Pp compared to those of Pg”
e1“Populus popularis, Pp”
e2“Populus alba × Populus glandulosa, Pg”
Claim · model-written summary
Low nitrogen decreased root influxes of ammonium and nitrate in both species.
PopulusNot reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“In both species, low N treatments decreased net influxes of NH4(+) and NO3(-)”
t0“poplar species”
Claim · model-written summary
Low nitrogen decreased root ammonium and foliar nitrate contents.
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“low N treatments decreased net influxes of NH4(+) and NO3(-), root NH4(+) and foliar NO3(-) content”
t0“poplar species”
Claim · model-written summary
Low nitrogen decreased root nitrate reductase activity and tissue nitrogen concentrations.
- Treatment
- low N treatmentse0
- Outcome
- root NR activities, total N concentration in roots and leavese0
- Direction
- decreasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“low N treatments decreased net influxes of NH4(+) and NO3(-), root NH4(+) and foliar NO3(-) content, root NR activities, total N concentration in roots and leaves”
t0“poplar species”
Claim · model-written summary
Low nitrogen decreased leaf transporter transcripts and root and leaf assimilation gene transcripts.
- Treatment
- low N treatmentse0
- Outcome
- transcript levels of most ammonium (AMTs) and nitrate (NRTs) transporter genes in leaves and genes involved in N assimilation in roots and leavese0
- Direction
- decreasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“low N treatments decreased net influxes of NH4(+) and NO3(-), root NH4(+) and foliar NO3(-) content, root NR activities, total N concentration in roots and leaves, and transcript levels of most ammonium (AMTs) and nitrate (NRTs) transporter genes in leaves and genes involved in N assimilation in roots and leaves”
t0“poplar species”
Claim · model-written summary
Low nitrogen increased fine root surface area.
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Low N availability increased fine root surface area”
t0“poplar species”
Claim · model-written summary
Low nitrogen increased foliar starch concentration and nitrogen isotope composition.
- Treatment
- Low N availabilitye0
- Outcome
- foliar starch concentration, δ(15)N in roots and leavese0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Low N availability increased fine root surface area, foliar starch concentration, δ(15)N in roots and leaves”
t0“poplar species”
Claim · model-written summary
Low nitrogen increased root transcript abundance of several ammonium and nitrate transporters.
- Treatment
- Low N availabilitye0
- Outcome
- transcript abundance of several AMTs (e.g. AMT1;2) and NRTs (e.g. NRT1;2 and NRT2;4B) in rootse0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Low N availability increased fine root surface area, foliar starch concentration, δ(15)N in roots and leaves, and transcript abundance of several AMTs (e.g. AMT1;2) and NRTs (e.g. NRT1;2 and NRT2;4B) in roots of both species”
t0“poplar species”
The same questions in other papers
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This paper is about lacking the nutrient, so it counts the other way round here.
- positive
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See all 23 papers →Claims are grouped by organism, treatment and what was measured or targeted. A paper counts as positive when any of its claims in the group is positive.