Regulation of photosystem II and key stress-response genes in Raphidiopsis raciborskii under combined chill/light stress

IF 2.2 4区环境科学与生态学 Q3 ECOLOGY

Aquatic Ecology Pub Date : 2026-06-03 DOI:10.1007/s10452-026-10316-z

Nada Tokodi, Adam Antosiak, Damjana Drobac Backović, Dariusz Dziga

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引用次数: 0

Abstract

Previous findings revealed strain-specific differences in pigment composition, photoprotective capacity, and photosynthetic efficiency among Raphidiopsis raciborskii strains. To complement these results, the present study examined four strains, three non-cylindrospermopsin-producing isolates from temperate regions in Poland and one strain from tropical Australia that produces this cyanotoxin, in order to elucidate acclimation mechanisms under combined chill/light stress using functional and molecular approaches. The investigation focused on photosystem II (PSII) performance and the expression of genes involved in transcriptional and translational regulation (rbp1, nusG), membrane remodelling (desA), photosynthetic function (ccr2), PSII repair (ftsH, fabZ), and compatible solute synthesis (asd). By combining JIP test analysis with gene expression profiling, the study integrates functional and transcriptional perspectives to better understand how R. raciborskii adjusts its photosynthetic machinery to environmental stress. JIP test analysis revealed distinct photosynthetic responses among strains under combined chill/light stress. Temperate strains exhibited increased energy dissipation (DI₀/RC) and activation of cyclic electron flow, enhancing photoprotection and PSII stability. The strain UAM/DH-MRr showed simultaneous enhancement of linear and cyclic electron transport, indicating flexible energy redistribution. Gene expression profiling demonstrated ecotype-specific acclimation strategies. Early activation of transcriptional regulators (nusG, rpb1) was followed by the induction of membrane remodelling (desA), PSII repair (ftsH, fabZ), and compatible solute synthesis (asd). The tropical strain CS-506 displayed the most extensive and sustained transcriptional response, while temperate strains showed rapid or delayed activation. The weakest response in UAM/DH-MRr suggested tolerance or pre-adaptation. Overall, these results highlight flexible, strain-dependent acclimation mechanisms that underpin the ecological success and climatic adaptability of R. raciborskii.

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冷/光联合胁迫下Raphidiopsis raciborskii光系统及关键胁迫响应基因的调控

先前的研究结果表明，不同菌株在色素组成、光保护能力和光合效率方面存在差异。为了补充这些结果，本研究检测了4株菌株，其中3株来自波兰温带地区的产生非柱状精子素的菌株和1株来自澳大利亚热带地区的产生这种蓝藻毒素的菌株，以便利用功能和分子方法阐明冷/光联合胁迫下的驯化机制。研究重点是光系统II （PSII）的性能以及参与转录和翻译调控的基因（rbp1, nusG）、膜重塑（desA）、光合功能（ccr2）、PSII修复（ftsH, fabZ）和相容溶质合成（asd）的表达。通过将JIP测试分析与基因表达谱相结合，该研究将功能和转录角度结合起来，以更好地了解r.r raciborskii如何调节其光合机制以适应环境胁迫。JIP试验分析表明，在冷/光联合胁迫下，各品系的光合响应有明显差异。温带菌株表现出更高的能量耗散（DI 0 /RC）和循环电子流激活，增强了光保护和PSII稳定性。应变UAM/DH-MRr显示线性和循环电子输运同时增强，表明能量再分配具有柔性。基因表达谱显示了生态型特异性驯化策略。转录调节因子（nusG, rpb1）的早期激活随后诱导膜重塑（desA）， PSII修复（ftsH, fabZ）和相容溶质合成（asd）。热带菌株CS-506表现出最广泛和持续的转录反应，而温带菌株表现出快速或延迟的激活。在UAM/DH-MRr中反应最弱提示耐受或预适应。总的来说，这些结果强调了灵活的、依赖于品系的驯化机制，这些机制支持了鼠尾草的生态成功和气候适应性。

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来源期刊

Aquatic Ecology 环境科学-海洋与淡水生物学

CiteScore

3.90

自引率

0.00%

发文量

审稿时长

3 months

期刊介绍： Aquatic Ecology publishes timely, peer-reviewed original papers relating to the ecology of fresh, brackish, estuarine and marine environments. Papers on fundamental and applied novel research in both the field and the laboratory, including descriptive or experimental studies, will be included in the journal. Preference will be given to studies that address timely and current topics and are integrative and critical in approach. We discourage papers that describe presence and abundance of aquatic biota in local habitats as well as papers that are pure systematic. The journal provides a forum for the aquatic ecologist - limnologist and oceanologist alike- to discuss ecological issues related to processes and structures at different integration levels from individuals to populations, to communities and entire ecosystems.