Abstract Agarophyton vermiculophyllum is a commercially important red alga for agar production in the Northwest Pacific Ocean and is an invasive seaweed in Europe. High temperature is an important environmental stressor that influences its growth, metabolism, and migration. Nevertheless, little is known about the molecular mechanisms underpinning the response of A. vermiculophyllum to heat stress. Using RNA-sequencing, we performed the first comprehensive transcriptome analysis of A. vermiculophyllum under heat stress to explore and identify potentially important heat stress-responsive genes. After de novo assembly of the transcriptome, 55,486 unigenes were found, of which 39,687 unigenes (71.52%) were functionally annotated. In total, 2,923 differentially expressed genes (DEGs) were detected between heat-stressed and control samples. Heat shock proteins represented the most abundant DEGs. Transcript factors were also significantly differently expressed under heat stress. Meanwhile, the photoprotective mechanism based on PsbS (Photosystem II subunit S) related nonphotochemical quenching and PGR5 (proton gradient regulation 5) dependent cyclic electron flow around photosystem I was found to be promoted under heat stress, which may help A. vermiculophyllum to cope with the high temperature. This study lays an important foundation for further elucidation of the molecular mechanism underlying heat tolerance in A. vermiculophyllum.

中文翻译：

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RNA测序综合分析和鉴定蚯蚓植物热响应基因

摘要 Agarophyton vermiculophyllum 是西北太平洋用于琼脂生产的重要商业红藻，是欧洲的入侵海藻。高温是影响其生长、代谢和迁移的重要环境压力源。然而，关于支持 A. vermiculophyllum 对热应激反应的分子机制知之甚少。使用 RNA 测序，我们在热应激下对 A. vermiculophyllum 进行了第一次全面的转录组分析，以探索和鉴定潜在的重要热应激反应基因。在转录组从头组装后，发现了 55,486 个 unigenes，其中 39,687 个 unigenes (71.52%) 被功能注释。在热应激样本和对照样本之间总共检测到 2,923 个差异表达基因 (DEG)。热休克蛋白代表最丰富的 DEG。转录因子在热应激下的表达也有显着差异。同时，发现基于 PsbS（光系统 II 亚基 S）相关的非光化学猝灭和 PGR5（质子梯度调节 5）依赖的光系统 I 周围循环电子流的光保护机制在热应激下得到促进，这可能有助于 A. vermiculophyllum 应对高温。本研究为进一步阐明A. vermiculophyllum耐热性的分子机制奠定了重要基础。发现基于 PsbS（光系统 II 亚基 S）相关的非光化学猝灭和 PGR5（质子梯度调节 5）依赖光系统 I 周围循环电子流的光保护机制在热应激下得到促进，这可能有助于 A. vermiculophyllum 应对高温度。本研究为进一步阐明A. vermiculophyllum耐热性的分子机制奠定了重要基础。发现基于 PsbS（光系统 II 亚基 S）相关的非光化学猝灭和 PGR5（质子梯度调节 5）依赖光系统 I 周围循环电子流的光保护机制在热应激下得到促进，这可能有助于 A. vermiculophyllum 应对高温度。本研究为进一步阐明A. vermiculophyllum耐热性的分子机制奠定了重要基础。