1. Photosynthesis in newly developed leaves of heat-tolerant wheat acclimates to long-term nocturnal warming.
- Author
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Coast, Onoriode, Scafaro, Andrew P, Bramley, Helen, Taylor, Nicolas L, and Atkin, Owen K
- Subjects
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ELECTRON transport , *WHEAT , *PHOTOSYNTHESIS , *WHEAT farming , *PHOTOSYNTHETIC rates - Abstract
We examined photosynthetic traits of pre-existing and newly developed flag leaves of four wheat genotypes grown in controlled-environment experiments. In newly developed leaves, acclimation of the maximum rate of net CO2 assimilation (A n) to warm nights (i.e. increased A n) was associated with increased capacity of Rubisco carboxylation and photosynthetic electron transport, with Rubisco activation state probably contributing to increased Rubisco activity. Metabolite profiling linked acclimation of A n to greater accumulation of monosaccharides and saturated fatty acids in leaves; these changes suggest roles for osmotic adjustment of leaf turgor pressure and maintenance of cell membrane integrity. By contrast, where A n decreased under warm nights, the decline was related to lower stomatal conductance and rates of photosynthetic electron transport. Decreases in A n occurred despite higher basal PSII thermal stability in all genotypes exposed to warm nights: T crit of 45–46.5 °C in non-acclimated versus 43.8–45 °C in acclimated leaves. Pre-existing leaves showed no change in A n–temperature response curves, except for an elite heat-tolerant genotype. These findings illustrate the impact of night-time warming on the ability of wheat plants to photosynthesize during the day, thereby contributing to explain the impact of global warming on crop productivity. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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