Laza Haydee, Bhattarai Bishwoyog, Mendu Venugopal, Burow Mark D, Emendack Yves, Sanchez Jacobo, Gupta Aarti, Abdelrahman Mostafa, Tran Lam-Son Phan, Tissue David T, Payton Paxton
Department of Plant and Soil Science, Texas Tech University, Lubbock, TX, United States.
Division of Plant Science and Technology, University of Missouri-Columbia, Columbia, MO, United States.
Front Plant Sci. 2025 Mar 27;15:1407574. doi: 10.3389/fpls.2024.1407574. eCollection 2024.
Elevated atmospheric carbon dioxide [CO] increases peanut carbon assimilation and productivity. However, the molecular basis of such responses is not well understood. We tested the hypothesis that maintaining high photosynthesis under long-term elevated [CO] is associated with the shift in C metabolism gene expression regulation.
We used a field CO enrichment system to examine the effects of elevated [CO] (ambient + 250 ppm) across different soil water availability and plant developmental stages on the molecular responses in a peanut runner-type genotype. Plants under both [CO] treatments were grown in semiarid conditions. We evaluated a comparative leaf transcriptomic profile across three periodic water deficit/re-hydration (well-watered/recovery) cycles throughout the growing season using RNAseq analysis.
Our results showed that the transcriptome responses were influenced by [CO], water availability, and developmental stages. The traditional Mercator annotation analysis based on percentage total revealed that lipid metabolism, hormone biosynthesis, secondary metabolism, amino acid biosynthesis, and transport were the most regulated biological processes. However, our new approach based on the comparative relative percentage change per individual category across stages revealed new insights into the gene expression patterns of biological functional groups, highlighting the relevance of the C-related pathways regulated by elevated [CO].
The photosynthesis analysis showed that 1) The light reaction was the most upregulated pathway by elevated [CO] during water stress, 2) Photorespiration was downregulated across all stages, 3) Sucrose synthesis genes were upregulated by elevated [CO] before stress, 4) Starch synthesis genes were upregulated by elevated [CO] under drought periods, and 5) CO regulation of sucrose and starch degradation was critical under drought periods. Our findings provide valuable insights into the molecular basis underlying the photosynthetic acclimation response to elevated [CO] in peanuts.
大气中二氧化碳（[CO₂]）浓度升高可提高花生的碳同化和生产力。然而，这种响应的分子基础尚未得到充分理解。我们检验了这样一个假设，即在长期[CO₂]浓度升高的情况下维持高光合作用与碳代谢基因表达调控的转变有关。
我们使用田间CO₂富集系统，研究了在不同土壤水分有效性和植物发育阶段，[CO₂]浓度升高（环境浓度 + 250 ppm）对花生蔓生型基因型分子响应的影响。两种[CO₂]处理下的植株均在半干旱条件下生长。我们使用RNAseq分析评估了整个生长季节中三个周期性水分亏缺/复水（充分浇水/恢复）循环的比较叶片转录组图谱。
我们的结果表明，转录组响应受[CO₂]、水分有效性和发育阶段的影响。基于百分比总量的传统Mercator注释分析表明，脂质代谢、激素生物合成、次生代谢、氨基酸生物合成和转运是调控最为显著的生物学过程。然而，我们基于各阶段单个类别比较相对百分比变化的新方法揭示了生物功能组基因表达模式的新见解，突出了[CO₂]浓度升高对碳相关途径调控的相关性。
光合作用分析表明，1）在水分胁迫期间，光反应是[CO₂]浓度升高上调最显著的途径；2）在所有阶段光呼吸均下调；3）在胁迫前，[CO₂]浓度升高上调了蔗糖合成基因；4）在干旱时期，[CO₂]浓度升高上调了淀粉合成基因；5）在干旱时期，[CO₂]对蔗糖和淀粉降解的调控至关重要。我们的研究结果为花生对[CO₂]浓度升高的光合适应响应的分子基础提供了有价值的见解。
