Effect of heat wave on N2 fixation and N remobilisation of lentil (Lens culinaris MEDIK) grown under free air CO2 enrichment in a mediterranean‐type environment. (16th October 2019)

• Record Type: Journal Article
• Authors: Parvin, S.; Uddin, S.; Bourgault, M.; Delahunty, A.; Nuttall, J.; Brand, J.; O'Leary, G.; Fitzgerald, G. J.; Armstrong, R.; Tausz, M.
• Editors: De Kok, L. J.
• Is Part Of: Plant biology. Volume 22(2020)Supplement 1
• Page Start: 123
• Page End: 132
• Publication Date: 2019-10-16
• Subjects: Elevated [CO2] -- free amino acids -- grain nitrogen concentration -- N2 fixation -- nodulation -- short‐term high temperature -- water‐soluble carbohydrates; Botany -- Periodicals; Plants -- genetics -- Periodicals; Plants -- growth & development -- Periodicals; Plant Proteins -- Periodicals; Gene Expression Regulation, Plant -- Periodicals; Botanique -- Périodiques; 580
• DOI: 10.1111/plb.13047
• Languages: English
• ISSNs: 1435-8603

Abstract

Abstract: The stimulatory effect of elevated [CO2 ] (e[CO2 ]) on crop production in future climates is likely to be cancelled out by predicted increases in average temperatures. This effect may become stronger through more frequent and severe heat waves, which are predicted to increase in most climate change scenarios. Whilst the growth and yield response of some legumes grown under the interactive effect of e[CO2 ] and heat waves has been studied, little is known about how N2 fixation and overall N metabolism is affected by this combination. To address these knowledge gaps, two lentil genotypes were grown under ambient [CO2 ] (a[CO2 ], ~400 µmol·mol −1 ) and e[CO2 ] (~550 µmol·mol −1 ) in the Australian Grains Free Air CO2 Enrichment facility and exposed to a simulated heat wave (3‐day periods of high temperatures ~40 °C) at flat pod stage. Nodulation and concentrations of water‐soluble carbohydrates (WSC), total free amino acids, N and N2 fixation were assessed following the imposition of the heat wave until crop maturity. Elevated [CO2 ] stimulated N2 fixation so that total N2 fixation in e[CO2 ]‐grown plants was always higher than in a[CO2 ], non‐stressed control plants. Heat wave triggered a significant decrease in active nodules and WSC concentrations, but e[CO2 ] had the opposite effect. Leaf N remobilization and grain N improved under interaction of e[CO2 ] and heat wave. These results suggested that larger WSC pools and nodulation under e[CO2 ] can support post‐heat wave recovery of N2 fixation. Elevated [CO2 ]‐induced accelerated leaf N remobilisation might contribute to restore grain N concentration following a heat wave. Abstract : Elevated [CO2] increased water soluble carbohydrate (WSC) supply to ensure greater active nodulation and maintained grain N concentration ([N]) through accelerated leaf N remobilization following heat wave. Thus, greater WSC pools and nodulation under elevated [CO2] can support post‐ heat‐wave recovery of N2 fixation and ensure grain [N].