Seagrasses are submerged marine angiosperms often prone to various biotic and abiotic stress factors in the marine environment. Our study investigated the response, adaptation and underlying tolerance mechanism of tropical seagrass Halodule pinifolia upon temperature stress (24°, 29°, 37°, and 45°C) and evaluated the effect of temperature stress on net photosynthesis (ΔF/ F'_m)and dark respiration (F_v/F_m). In this study, metabolomic analysis of seagrass H. pinifolia upon heat stress has been performed using GC-MS based omics approach. As a result, the net photosynthetic efficiency (ΔF/ F'_m) was found significantly decreased upon heat stress, while the dark respiration rate was increased to 2.903 mg O₂/ g FW h^-1 and 3.87 mg O₂/ g FW h^-1 as compared to the control (24° C), respectively. Metabolomic analysis showed heat stress could cause large metabolite variations with respect to sugar, amino acids and organic acids. Interestingly, three thermo- protective metabolites such as trehalose (sugar), glycine betaine (amino acid) and methyl vinyl ketone (organic acid) were profiled from H. pinifolia (45°C) and is the first report on the occurrence of glycine betaine and methyl vinyl ketone from seagrasses and other aquatic species so far. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis demonstrated H. pinifolia exposed to heat stress lead to intense biochemical changes and caused significant variations in the heat responsive metabolic pathways. The present findings would facilitate the further research on identifying gene to metabolite networks for an effective management of seagrass conservation by genetic manipulation.

海草是被淹没的海洋被子植物，在海洋环境中经常容易受到各种生物和非生物胁迫因素的影响。我们的研究调查的响应，适应和热带海草的底层公差机构羽叶二药藻于温度应力（24°，29°，37°，和45°C），评价温度胁迫对净光合作用（ΔF/ F”_米）和黑暗呼吸（F _v / F _m）。在这项研究中，已经使用基于GC-MS的组学方法对热胁迫下的海草H. pinifolia进行了代谢组学分析。其结果是，净光合效率（ΔF/ F”_米）被发现在热胁迫下显着降低，而暗呼吸率分别比对照组（24°C）增加到2.903 mg O ₂ / g FW h ^-1和3.87 mg O ₂ / g FW h ^-1。代谢组学分析表明，热应激可能导致糖，氨基酸和有机酸的代谢产物发生较大变化。有趣的是，从H. pinifolia提取了三种热保护性代谢物，例如海藻糖（糖），甘氨酸甜菜碱（氨基酸）和甲基乙烯基酮（有机酸）。（45°C），是迄今为止有关海草和其他水生物种中甘氨酸甜菜碱和甲基乙烯基酮的首次报道。京都市基因与基因组百科全书（KEGG）途径分析表明，暴露于热胁迫下的松叶芥导致强烈的生化变化，并引起热响应代谢途径的显着变化。本研究结果将有助于进一步研究鉴定基因到代谢物网络以通过基因操作有效管理海草保护。