Ramakers Lennart A I, Harbinson Jeremy, van Amerongen Herbert
Laboratory of Biophysics, Wageningen University, Wageningen, the Netherlands.
Physiol Plant. 2025 Jul-Aug;177(4):e70420. doi: 10.1111/ppl.70420.
When light absorption exceeds photochemical quenching, plants activate non-photochemical quenching (NPQ) to dissipate excess energy as heat. Recently, we have developed a novel multivariate pipeline for NPQ induction analysis. Applying this pipeline to NPQ induction curves of several Arabidopsis thaliana NPQ genotypes, overturns the long-held belief that zeaxanthin (Zx) accelerates NPQ induction upon light-adaptation. We demonstrate that the observed acceleration is solely due to the action of PsbS. Our approach allows the synergistic inter-relationships between PsbS and Zx to be unambiguously explored. Specifically, we applied our analysis to dark- and light-adapted wild-type (wt), Zx-lacking (npq1), Zx-rich (npq2) and PsbS-lacking (npq4) A. thaliana. Only the PsbS-dependent quenching in npq2, wt and npq1 plants exhibited faster induction kinetics following light adaptation. Changes in the Zx-levels (npq1 → wt → npq2) lead to changes in the overall amplitudes of the PsbS-components, revealing a Zx-driven amplification of PsbS-dependent quenching. In the presence of PsbS (npq2/wt), Zx also provides its own distinct contribution to NPQ. Together, this reveals the distinct roles of Zx in NPQ and the multilayered synergistic relationship between PsbS and Zx. Combined with mutant genotypes, our unique analysis is an invaluable toolkit to answer mechanistic questions and will allow different NPQ models to be experimentally explored.
当光吸收超过光化学猝灭时，植物会激活非光化学猝灭（NPQ），将多余的能量以热量的形式耗散。最近，我们开发了一种用于NPQ诱导分析的新型多变量方法。将该方法应用于几种拟南芥NPQ基因型的NPQ诱导曲线，推翻了长期以来认为玉米黄质（Zx）在光适应时加速NPQ诱导的观点。我们证明观察到的加速完全是由于PsbS的作用。我们的方法能够明确探索PsbS和Zx之间的协同相互关系。具体而言，我们将分析应用于暗适应和光适应的野生型（wt）、缺乏Zx的（npq1）、富含Zx的（npq2）和缺乏PsbS的（npq4）拟南芥。只有npq2、wt和npq1植株中依赖PsbS的猝灭在光适应后表现出更快的诱导动力学。Zx水平的变化（npq1→wt→npq2）导致PsbS组分的总体幅度发生变化，揭示了Zx驱动的依赖PsbS的猝灭放大。在存在PsbS的情况下（npq2/wt），Zx也对NPQ有其独特的贡献。总之，这揭示了Zx在NPQ中的独特作用以及PsbS和Zx之间的多层协同关系。结合突变基因型，我们独特的分析是回答机制问题的宝贵工具包，并将允许对不同的NPQ模型进行实验探索。
