Molecular and physiological responses during thermal acclimation of leaf photosynthesis and respiration in rice Article Swipe
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· 2019
· Open Access
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· DOI: https://doi.org/10.1111/pce.13706
· OA: W2995023592
To further our understanding of how sustained changes in temperature affect the carbon economy of rice ( Oryza sativa ), hydroponically grown plants of the IR64 cultivar were developed at 30°C/25°C (day/night) before being shifted to 25/20°C or 40/35°C. Leaf messenger RNA and protein abundance, sugar and starch concentrations, and gas‐exchange and elongation rates were measured on preexisting leaves (PE) already developed at 30/25°C or leaves newly developed (ND) subsequent to temperature transfer. Following a shift in growth temperature, there was a transient adjustment in metabolic gene transcript abundance of PE leaves before homoeostasis was reached within 24 hr, aligning with R dark (leaf dark respiratory CO 2 release) and A n (net CO 2 assimilation) changes. With longer exposure, the central respiratory protein cytochrome c oxidase (COX) declined in abundance at 40/35°C. In contrast to R dark , A n was maintained across the three growth temperatures in ND leaves. Soluble sugars did not differ significantly with growth temperature, and growth was fastest with extended exposure at 40/35°C. The results highlight that acclimation of photosynthesis and respiration is asynchronous in rice, with heat‐acclimated plants exhibiting a striking ability to maintain net carbon gain and growth when exposed to heat‐wave temperatures, even while reducing investment in energy‐conserving respiratory pathways.
