Abstract Endophytes; a ubiquitous group of microorganisms considered as a gem box of bioactive constituents of medical significance. Studies on this emerging field is very less among the research communities. The present study focused on the molecular phylogenetics of the endophytic fungus that associated with the leaf of Kayea assamica, an endemic plant species of Northeast India and identification of its secondary metabolites (natural product) that produced under in vitro condition. The endogenous fungus was isolated from the sterile disease-free leaf segment (1 cm), followed by PCR amplification of ITS region using the extracted genomic DNA as a template. Further, the crude methanol extract of the fungal culture was subjected to Gas Chromatography-Mass Spectrometry (GC–MS) analysis. The molecular phylogenetic analysis confirmed the fungal isolate as Beltraniella species (endophyte). The ITS sequence was submitted to GenBank database (Id MH295767.1). The GC-MS analysis revealed eleven different secondary metabolites at different retention times. Many of these compounds have been reported to be plant & endophytic metabolite, essential oil component, recognized fragrant molecule, antimicrobial, antioxidant, anticancer activities etc. The findings projected that the endophyte may have a significant role in the host-defense mechanism. Tetrapentacontane is a part of fragrant molecules found in juvenile agarwood shown highest abundance (54.63%) at 21.477 RT followed by the others. This study performed for the first time on endosymbiotic microorganism present in the respective plant species and highlighted this endophytic fungus as a unique source of non-plant based bioactive compounds with future biotechnological consequence.

中文翻译：

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一种与 kayea assamica (King & Prain) 相关的内生真菌：对其分子系统发育和天然产物的研究

摘要内生菌；一种无处不在的微生物群，被认为是具有医学意义的生物活性成分的宝石盒。在研究社区中，对这一新兴领域的研究非常少。本研究的重点是与印度东北部特有植物 Kayea assamica 叶相关的内生真菌的分子系统发育及其在体外条件下产生的次生代谢物（天然产物）的鉴定。从无菌无病叶段（1 cm）中分离出内源真菌，然后以提取的基因组DNA为模板对ITS区域进行PCR扩增。此外，对真菌培养物的粗甲醇提取物进行气相色谱-质谱 (GC-MS) 分析。分子系统发育分析证实该真菌分离物为贝尔特兰属（Beltraniella）种（内生菌）。ITS 序列已提交到 GenBank 数据库（Id MH295767.1）。GC-MS 分析揭示了 11 种不同保留时间的不同次生代谢物。据报道，这些化合物中有许多是植物和内生菌代谢物、精油成分、公认的芳香分子、抗菌、抗氧化、抗癌活性等。研究结果预测内生菌可能在宿主防御机制中发挥重要作用。四十五烷是在幼年沉香木中发现的芳香分子的一部分，在 21.477 RT 下显示出最高的丰度 (54.63%)，其次是其他。