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 Rdark (leaf dark respiratory CO2 release) and An (net CO2 assimilation) changes. With longer exposure, the central respiratory protein cytochrome c oxidase (COX) declined in abundance at 40/35°C. In contrast to Rdark , An 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.

中文翻译：

---

水稻叶片光合作用和呼吸热适应过程中的分子和生理响应。

为了进一步了解温度的持续变化如何影响水稻（Oryza sativa）的碳经济，将IR64品种的水培植物在30°C / 25°C（昼/夜）发育，然后移至25/20。 °C或40/35°C。在30/25°C下已经发育的叶片（PE）或温度转移后新发育的叶片（ND）上测量了叶片的信使RNA和蛋白质的丰度，糖和淀粉的浓度以及气体交换和伸长率。随着生长温度的变化，在24小时内达到稳态之前，PE叶的代谢基因转录丰度发生了短暂的调整，与Rdark（叶暗呼吸CO2释放）和An（净CO2同化）变化一致。曝光时间越长，在40/35°C，中央呼吸蛋白细胞色素C氧化酶（COX）大量减少。与Rdark相比，ND叶片在三个生长温度下均保持An值。可溶性糖的浓度随生长温度的变化无明显差异，并且在40/35°C下长时间暴露于生长最快。结果表明，水稻的光合作用和呼吸适应是不同步的，受热适应的植物在暴露于热波温度时仍表现出惊人的保持净碳增长和增长的能力，甚至减少了在节能呼吸途径上的投资。在40/35°C下长时间接触会导致生长最快。结果表明，水稻的光合作用和呼吸适应是不同步的，受热适应的植物在暴露于热波温度时仍表现出惊人的保持净碳增长和增长的能力，甚至减少了在节能呼吸途径上的投资。在40/35°C下长时间接触会导致生长最快。结果表明，水稻的光合作用和呼吸适应是不同步的，受热适应的植物在暴露于热波温度时仍表现出惊人的保持净碳增长和增长的能力，甚至减少了在节能呼吸途径上的投资。