Parvin, S., Uddin, S.,
Bourgault, M., Delahunty, A.,
Nuttall, J., Brand, J.,
O'Leary, G., Fitzgerald, G.J.,
Armstrong, R. and Tausz, M.
2019
Effect of heat wave
on N2 fixation and
N remobilization of lentil
( Lens culinaris MEDIK )
grown under free air
CO2 enrichment in a
Mediterranean-type
environment.
Plant Biology doi: 10.1111/plb.13047.
NOTE:
Parvin et al. (2019) set out to examine "the mechanisms and to what extent elevated CO2 can mitigate the heat wave effects on N2 fixation and grain nitrogen concentration of lentil, and whether this response varies between genotypes."
SUMMARY:
Parvin et al. conclude "this study provides evidence that elevated CO2-grown lentil genotypes (cv. PBA Ace and HS3010) that are exposed to acute heat wave conditions, during the flat pod phase, can maintain N2 fixation above that of ambient CO2 non-stress control plants."
They add that "increased WSC availability and higher nodulation response under elevated CO2 can reduce the negative impact of a heat wave on N2 fixation."
"Net assimilation rate (Anet) was higher in plants growing under elevated CO2 compared to ambient CO2"
Elevated CO2 "increased N2 fixation of lentil by 30%" (Figure 2) and "the increased N2 fixation was associated with higher active/viable nodule biomass."
DETAILS:
Work was conducted at the Australian Grain Free Air CO2 Enrichment (AGFACE) facility near Horsham, Victoria, Australia, using two lentil cultivars (PBA Ace and HS3010).
The plants were subjected to either ambient (400 ppm) or elevated levels of CO2 (550 ppm during daylight hours only) for the length of the growing season.
At the flat pod stage (R4) a heat treatment was imposed on a subset of plant in each CO2 treatment for three days.
Each day the heat treatment lasted from 0900 to 1600 hours and temperatures in the canopy were increased to 7 °C above ambient levels, reaching a target temperature of 40 °C.
Chart Below:
