Zhang Peng, Sharwood Robert E, Carroll Adam, Estavillo Gonzalo M, von Caemmerer Susanne, Furbank Robert T
Research School of Biology, The Australian National University, Canberra, ACT 2601, Australia.
ARC Centre of Excellence for Translational Photosynthesis, The Australian National University, Canberra, ACT 2601, Australia.
Plant Cell. 2025 Apr 2;37(4). doi: 10.1093/plcell/koaf005.
Many C4 plants are used as food and fodder crops and often display improved resource use efficiency compared to C3 plants. However, the response of C4 plants to future extreme conditions such as heatwaves is less understood. Here, Setaria viridis, an emerging C4 model grass, was grown under long-term high-temperature stress for 2 wk (42 °C, compared to 28 °C). This resulted in stunted growth, but surprisingly had little impact on leaf thickness, leaf area-based photosynthetic rates, and bundle sheath leakiness. Dark respiration rates increased, and there were major alterations in carbon and nitrogen metabolism in the heat-stressed plants. Abscisic acid and indole-3-acetic acid-amino acid conjugates accumulated in the heat-stressed plants, consistent with transcriptional changes. Leaf transcriptomics, proteomics, and metabolomics analyses were carried out and mapped onto the metabolic pathways of photosynthesis, respiration, carbon/nitrogen metabolism, and phytohormone biosynthesis and signaling. An in-depth analysis of correlations between transcripts and their corresponding proteins revealed strong differences between groups in the strengths and signs of correlations. Overall, many stress signaling pathways were upregulated, consistent with multiple signals leading to reduced plant growth. A systems-based model of the plant response to long-term heat stress is presented based on the oxidative stress, phytohormone, and sugar signaling pathways.
许多C4植物被用作粮食和饲料作物，与C3植物相比，它们通常表现出更高的资源利用效率。然而，人们对C4植物在未来诸如热浪等极端条件下的反应了解较少。在这里，新兴的C4模式草绿狗尾草在长期高温胁迫（42°C，对比28°C）下生长2周。这导致了生长发育迟缓，但令人惊讶的是，对叶片厚度、基于叶面积的光合速率和维管束鞘渗漏几乎没有影响。暗呼吸速率增加，热胁迫植物的碳和氮代谢发生了重大变化。脱落酸和吲哚-3-乙酸-氨基酸结合物在热胁迫植物中积累，这与转录变化一致。进行了叶片转录组学、蛋白质组学和代谢组学分析，并将其映射到光合作用、呼吸作用、碳/氮代谢以及植物激素生物合成和信号传导的代谢途径上。对转录本与其相应蛋白质之间相关性的深入分析揭示了不同组在相关性强度和正负号方面的显著差异。总体而言，许多胁迫信号通路被上调，这与多种信号导致植物生长减缓一致。基于氧化应激、植物激素和糖信号通路，提出了一个基于系统的植物对长期热胁迫反应的模型。
