Huang Jianbei, Reichelt Michael, Chowdhury Somak, Hammerbacher Almuth, Hartmann Henrik
Max Planck Institute for Biogeochemistry, Hans-Knöll-Str. 10, D-07745, Jena, Germany.
Max Planck Institute for Chemical Ecology, Hans-Knöll-Str. 8, D-07745, Jena, Germany.
J Exp Bot. 2017 Feb 1;68(5):1251-1263. doi: 10.1093/jxb/erx008.
Phytohormones play important roles in plant acclimation to changes in environmental conditions. However, their role in whole-plant regulation of growth and secondary metabolite production under increasing atmospheric CO2 concentrations ([CO2]) is uncertain but crucially important for understanding plant responses to abiotic stresses. We grew winter wheat (Triticum aestivum) under three [CO2] (170, 390, and 680 ppm) over 10 weeks, and measured gas exchange, relative growth rate (RGR), soluble sugars, secondary metabolites, and phytohormones including abscisic acid (ABA), auxin (IAA), jasmonic acid (JA), and salicylic acid (SA) at the whole-plant level. Our results show that, at the whole-plant level, RGR positively correlated with IAA but not ABA, and secondary metabolites positively correlated with JA and JA-Ile but not SA. Moreover, soluble sugars positively correlated with IAA and JA but not ABA and SA. We conclude that increasing carbon availability stimulates growth and production of secondary metabolites via up-regulation of auxin and jasmonate levels, probably in response to sugar-mediated signalling. Future low [CO2] studies should address the role of reactive oxygen species (ROS) in leaf ABA and SA biosynthesis, and at the transcriptional level should focus on biosynthetic and, in particular, on responsive genes involved in [CO2]-induced hormonal signalling pathways.
植物激素在植物适应环境条件变化过程中发挥着重要作用。然而，在大气二氧化碳浓度（[CO₂]）升高的情况下，它们在植物整体生长调节和次生代谢产物合成中的作用尚不确定，但对于理解植物对非生物胁迫的响应至关重要。我们将冬小麦（Triticum aestivum）在三种[CO₂]浓度（170、390和680 ppm）下培养了10周，并在植物整体水平上测量了气体交换、相对生长速率（RGR）、可溶性糖、次生代谢产物以及包括脱落酸（ABA）、生长素（IAA）、茉莉酸（JA）和水杨酸（SA）在内的植物激素。我们的结果表明，在植物整体水平上，RGR与IAA呈正相关，与ABA无相关性，次生代谢产物与JA和茉莉酸异亮氨酸（JA-Ile）呈正相关，与SA无相关性。此外，可溶性糖与IAA和JA呈正相关，与ABA和SA无相关性。我们得出结论，碳供应增加通过上调生长素和茉莉酸水平刺激次生代谢产物的生长和合成，这可能是对糖介导信号的响应。未来低[CO₂]研究应关注活性氧（ROS）在叶片ABA和SA生物合成中的作用，在转录水平上应关注生物合成基因，特别是参与[CO₂]诱导激素信号通路的响应基因。
