Effect of Elevated CO₂ and Nitrogen Nutrition on Photosynthesis, Growth and Carbon‐Nitrogen Balance in Brassica juncea

Abstract

The response of Brassica juncea var. Bio‐183‐92 to elevated CO2 under increased nitrogen treatment was studied. There was an interactive effect of CO2 and nitrogen nutrition, indicating that, on the addition of more nitrogen, the plants sustained the positive effect of CO2 enrichment by utilizing additional carbohydrates for the development of new sinks. Excess carbohydrate enables plants to be flexible and responsive to additional nitrogen application to sustain the CO2 enrichment effect.

Effects of drought stress and N supply on the growth, biomass partitioning and water-use efficiency of Sophora davidii seedlings

“…Although drought stress slightly decreased RWC as many previous studies have reported (Chartzoulakis et al, 2002;Rosales-Serna et al, 2004;Bai et al, 2006), Nl also increased RWC under a drought stress condition, and RWC increased with the increase of N supply under well-watered condition. This was also in agreement with the findings of Uprety and Mahalaxmi (2000), which reported that additional N could enhance RWC.…”

Photosynthesis and nutrient composition of spinach and fenugreek grown under elevated carbon dioxide concentration

“…Stomatal conductance (g s ) decreased significantly in both spinach and fenugreek grown under ECO 2 ( Table 1). The increase in P N has been reported in various crop species by various researchers under ECO 2 (Aben et al 1999, Uprety andMahalaxmi 2000). In the present study, however, complete acclimation was not observed but the relative increase caused by ECO 2 decreased with time.…”

“…CO 2 being the primary substrate for photosynthesis influences several plant physiological processes directly as a result of this primary response, and a range of secondary responses, including growth, dry matter allocation, and nutrient composition and assimilation may change (Stitt and Krapp 1999, Schortemeyer et al 1999, Uprety et al 2003, Pal et al 2005.…”

Effects of elevated CO₂ and nitrogen on wheat growth and photosynthesis

“…There are indications of a decreased NR activity due to higher CO 2 levels (Ferrario-Mery et al 1997, Geiger et al 1998, Pal et al 2004 whereas more N resulted in increased NR activity (Cruz et al 2004). The interactions between elevated CO 2 and variable nitrogensupplies have been studied on rice (Aben et al 1999, Moynul Hague et al 2005 and Brassica (Uprety and Mahalaxmi 2000). The present experiment attempted to study the effects of elevated CO 2 and nitrogen doses on growth and photosynthetic characteristics of wheat.…”

“…This increased atmospheric CO 2 concentration is likely to influence growth, development and productivity of crop plants (Makino et al 2000). Many studies have reported reductions in plant N concentration due to elevated CO 2 , which can increase the ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco, EC 4.1.1.39) efficiency and cause mobilization of nitrogen (Makino et al 2000, Uprety andMahalaxmi 2000). Plants with increased Rubisco efficiency under EC could require less N for their biomass production (Sage et al 1988) but the changes in activity of nitrate reductase (NR, EC 1.6.6.1), a key enzyme involved in N assimilation in plants, under CO 2 enriched atmosphere is poorly known.…”