Effect of elevated CO₂on phosphorus nutrition of phosphate-deficientArabidopsis thaliana(L.) Heynh under different nitrogen forms

Abstract

Phosphorus (P) nutrition is always a key issue regarding plants responses to elevated CO2. Yet it is unclear of how elevated CO2 affects P uptake under different nitrogen (N) forms. This study investigated the influence of elevated CO2 (800 µl l–1) on P uptake and utilization by Arabidopsis grown in pH-buffered phosphate (P)-deficient (0.5 µM) hydroponic culture supplying with 2mM nitrate (NO3 −) or ammonium (NH4 +). After 7 d treatment, elevated CO2 enhanced the biomass production of both NO3 −- and NH4 +-fed plants but decreased the P amount absorbed per weight of roots and the P concentration in the shoots of plants supplied with NH4 +. In comparison, elevated CO2 increased the amount of P absorbed per weight of roots, as well as the P concentration in plants and alleviated P deficiency-induced symptoms of plants supplied with NO3 −. Elevated CO2 also increased the root/shoot ratio, total root surface area, and acid phosphatase activity, and enhanced the expression of genes or transcriptional factors involving in P uptake, allocation and remobilization in P deficient plants. Furthermore, elevated CO2 increased the nitric oxide (NO) level in roots of NO3 −-fed plants but decreased it in NH4 +-fed plants. NO scavenger 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (cPTIO) inhibited plant P acquisition by roots under elevated CO2. Considering all of these findings, this study concluded that a combination of elevated CO2 and NO3 − nutrition can induce a set of plant adaptive strategies to improve P status from P-deficient soluble sources and that NO may be a signalling molecule that controls these processes.

Physiological and molecular alterations in plants exposed to high [CO2] under phosphorus stress

“…16 transcript levels of AtPAP2 (Niu et al, 2013 On the other hand, there are reports on decrease in APase activity with increasing [CO 2 ] and P fertilization in plants like T. repens and Ponderosa pine . In contrast, no significant change in APase activity in L. albus under high [CO 2 ] and high P supply was observed (Wasaki et al, 2003).…”

Plant growth responses to elevated atmospheric CO2are increased by phosphorus sufficiency but not by arbuscular mycorrhizas

“…In M. truncatula , roles in direct and AM pathways have been identified, but roles of individual genes are less clear in B. distachyon . Few studies have analyzed the effects of eCO 2 on PT gene expression, and these have been in the non-AM plant Arabidopsis thaliana (Niu et al , 2013; Pandey et al , 2015 b ). …”

Leaf concentrations of nitrogen and phosphorus in phaseolus vulgaris l. Plants under high CO2 concentration and drought stress

“…The drought stress reduce the stomatal conductance too, besides the leaf [N] and [P], due the lower mineral absorbing. Also, the reduction in leaf [N] in plants under high [CO2] (MIYAGI et al, 2007;GARTEN JR. et al, 2008;NIU et al, 2012), may result from physiological adjustment to increase the efficiency of nitrogen by high photosynthetic rate. This results in an increase in carbon absorbed rate per unit of leaf nitrogen and a decrease in leaf specific surface area and [N] per unit of dry matter.…”