Triose phosphate utilization in leaves is modulated by whole-plant sink-source ratios and nitrogen budgets in rice

Zhou Zhenxiang, Zhang Zichang, van der Putten Peter E.L., Fabre Denis, Dingkuhn Michael, Struik Paul C., Yin Xinyou. 2023. Triose phosphate utilization in leaves is modulated by whole-plant sink-source ratios and nitrogen budgets in rice. Journal of Experimental Botany, 74 (21) : 6692-6707.

Résumé : Triose phosphate utilization (TPU) is a biochemical process indicating carbon sink–source (im)balance within leaves. When TPU limits leaf photosynthesis, photorespiration-associated amino acid exports probably provide an additional carbon outlet and increase leaf CO2 uptake. However, whether TPU is modulated by whole-plant sink–source relations and nitrogen (N) budgets remains unclear. We address this question by model analyses of gas-exchange data measured on leaves at three growth stages of rice plants grown at two N levels. Sink–source ratio was manipulated by panicle pruning, by using yellower-leaf variant genotypes, and by measuring photosynthesis on adaxial and abaxial leaf sides. Across all these treatments, higher leaf N content resulted in the occurrence of TPU limitation at lower intercellular CO2 concentrations. Photorespiration-associated amino acid export was greater in high-N leaves, but was smaller in yellower-leaf genotypes, panicle-pruned plants, and for abaxial measurement. The feedback inhibition of panicle pruning on rates of TPU was not always observed, presumably because panicle pruning blocked N remobilization from leaves to grains and the increased leaf N content masked feedback inhibition. The leaf-level TPU limitation was thus modulated by whole-plant sink–source relations and N budgets during rice grain filling, suggesting a close link between within-leaf and whole-plant sink limitations.

Mots-clés Agrovoc : Oryza sativa, photosynthèse, stade de développement végétal, physiologie végétale, génotype, feuille, triose, échange gazeux, expérimentation en pot, croissance

Mots-clés libres : Oryza sativa, Triose phosphate utilization, Sink limitation, Panicle pruning

Classification Agris : F60 - Physiologie et biochimie végétale

Champ stratégique Cirad : CTS 2 (2019-) - Transitions agroécologiques

Auteurs et affiliations

• Zhou Zhenxiang, Wageningen University and Research Centre (NLD)
• Zhang Zichang, Wageningen University and Research Centre (NLD)
• van der Putten Peter E.L., Wageningen University and Research Centre (NLD)
• Fabre Denis, CIRAD-BIOS-UMR AGAP (FRA) ORCID: 0000-0002-6222-2587
• Dingkuhn Michael, CIRAD-BIOS-UMR AGAP (FRA)
• Struik Paul C., Wageningen Agricultural University (NLD)
• Yin Xinyou, Wageningen University and Research Centre (NLD) - auteur correspondant

Source : Cirad-Agritrop (https://agritrop.cirad.fr/606316/)

Métriques

[ Page générée et mise en cache le 2024-12-18 ]