Elevated CO₂ plus chronic warming reduce nitrogen uptake and levels or activities of nitrogen‐uptake and ‐assimilatory proteins in tomato roots

Abstract

Atmospheric CO enrichment is expected to often benefit plant growth, despite causing global warming and nitrogen (N) dilution in plants. Most plants primarily procure N as inorganic nitrate (NO ) or ammonium (NH ), using membrane-localized transport proteins in roots, which are key targets for improving N use. Although interactive effects of elevated CO , chronic warming and N form on N relations are expected, these have not been studied. In this study, tomato (Solanum lycopersicum) plants were grown at two levels of CO (400 or 700 ppm) and two temperature regimes (30 or 37°C), with NO or NH as the N source. Elevated CO plus chronic warming severely inhibited plant growth, regardless of N form, while individually they had smaller effects on growth. Although %N in roots was similar among all treatments, elevated CO plus warming decreased (1) N-uptake rate by roots, (2) total protein concentration in roots, indicating an inhibition of N assimilation and (3) shoot %N, indicating a potential inhibition of N translocation from roots to shoots. Under elevated CO plus warming, reduced NO -uptake rate per g root was correlated with a decrease in the concentration of NO -uptake proteins per g root, reduced NH uptake was correlated with decreased activity of NH -uptake proteins and reduced N assimilation was correlated with decreased concentration of N-assimilatory proteins. These results indicate that elevated CO and chronic warming can act synergistically to decrease plant N uptake and assimilation; hence, future global warming may decrease both plant growth and food quality (%N).

Effect of drought and carbon dioxide on nutrient uptake and levels of nutrient‐uptake proteins in roots of barley

“…For each nutrient-uptake protein, rabbit polyclonal antiserum was generated using oligopeptide antigens of conserved domains that were designed using bioinformatics, as described in detail by Jayawardena et al (2017). The oligopeptide antigens were TGGLKSSVSGFGSDQFDESD for NRT1, KLLRISAEDEMAGMDLTRH for AMT1, and GDYPLSATIMSEYANKKTRG for PHT1.…”

Elevated CO2 Improves Photosynthesis Under High Temperature by Attenuating the Functional Limitations to Energy Fluxes, Electron Transport and Redox Homeostasis in Tomato Leaves

“…Being sessile, most plants inherently possess the ability to adjust their photosynthetic characteristics following a change in their growth temperatures. Heat stress causes dehydration in aerial plant parts, oxidative damage to biomembranes due to increases in reactive oxygen species (ROS) production, decreased growth and a consequent reduction in water use efficiency ( Li et al, 2016 ; Jayawardena et al, 2017 ). Damage to any component of photosynthesis such as photosynthetic pigments, the two photosystems (PS I & II), electron transport chain, and CO 2 reduction pathways, is sufficient enough to hinder the overall photosynthetic mechanism of a plant ( Brestic et al, 2018 ).…”

Effects of Elevated Carbon Dioxide on Photosynthesis and Carbon Partitioning: A Perspective on Root Sugar Sensing and Hormonal Crosstalk

“…Sugars produced from photosynthesis are transported into roots where they can assist in regulating nutrient uptake via sugar sensing (Camañes et al, 2007 ; Lejay et al, 2008 ), though little research has been done in this area. How e[CO 2 ] affects root function is not entirely understood, but we do know that it can affect the acquisition of soil nutrients (Taub and Wang, 2008 ; Pandey et al, 2015 ; Jayawardena et al, 2017 ). To what extent sugars may play a role in this is not currently known.…”