No genomic sequence of Mycobacterium isolated from orchids has been reported yet; therefore, this study intends to analyze the complete genomic sequence of a growth-promoting Mycobacterium from orchid Doritaenopsis . Mycobacterium strain Mya-zh01 was isolated from the flower stalk of Doritaenopsis Jiuhbao Red Rose . Our results show that Mya-zh01 can effectively produce and secrete the plant growth hormone indole-3-acetic acid (IAA). Inoculation of Mya-zh01 increased root number and length, plant height, leaf number, and leaf length in Doritaenopsis . Furthermore, inoculation of Mya-zh01 promotes seed germination in Doritaenopsis . We sequenced and assembled chromosome for Mya-zh01 (5,027,704 bp with 68.48% GC content), which was predicted to encode 4968 proteins with functions in oxidation reduction, growth, plasma membrane, ATP and DNA binding, carbon metabolism and biosynthesis of amino acids pathways. Mya-zh01 may trap iron from nature or host cells to facilitate the growth of the orchids by producing two siderophores (Mycobactin and Nocobactin NA). Four pathways (tryptamine, indole-3-acetamide, indole-3-pyruvate, and flavin monooxygenase) and seven enzymes [tryptophan synthase alpha chain, tryptophan synthase beta chain, amidase, monoamine oxidase, indole-3-pyruvate monooxygenase, indole-3-pyruvate decarboxylase and aldehyde dehydrogenase (NAD +)] involved in IAA biosynthesis were predicted in Mya-zh01 genome. In conclusion, this study demonstrated the significance of Mya-zh01 in facilitating plant growth and seed germination in Doritaenopsis by IAA biosynthesis, which provides a new insight into the mechanism of plant–bacteria interaction in Doritaenopsis .

中文翻译：

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内生细菌 Mycobacterium Mya-zh01 的完整基因组序列促进植物生长和种子萌发从 Doritaenopsis 花茎中分离

尚未报道从兰花中分离出的分枝杆菌基因组序列；因此，本研究旨在分析来自兰花 Doritaenopsis 的促生长分枝杆菌的完整基因组序列。分枝杆菌菌株Mya-zh01 是从Doritaenopsis 九宝红蔷薇的花茎中分离得到的。我们的结果表明，Mya-zh01 可以有效地产生和分泌植物生长激素吲哚-3-乙酸 (IAA)。接种 Mya-zh01 增加了 Doritaenopsis 的根数和长度、株高、叶数和叶长。此外，接种 Mya-zh01 可促进 Doritaenopsis 的种子萌发。我们对 Mya-zh01（5,027,704 bp，GC 含量为 68.48%）的染色体进行测序和组装，预测其编码 4968 种具有氧化还原、生长、质膜、ATP 和 DNA 结合功能的蛋白质，氨基酸途径的碳代谢和生物合成。Mya-zh01 可以从自然界或宿主细胞中捕获铁，通过产生两种铁载体（分枝杆菌素和 Nocobactin NA）促进兰花的生长。四种途径（色胺、吲哚-3-乙酰胺、吲哚-3-丙酮酸和黄素单加氧酶）和七种酶[色氨酸合酶α链、色氨酸合酶β链、酰胺酶、单胺氧化酶、吲哚-3-丙酮酸单加氧酶、吲哚-3在 Mya-zh01 基因组中预测了参与 IAA 生物合成的 -丙酮酸脱羧酶和醛脱氢酶 (NAD +)]。总之，本研究证明了 Mya-zh01 通过 IAA 生物合成促进 Doritaenopsis 植物生长和种子萌发的重要性，为 Doritaenopsis 植物 - 细菌相互作用的机制提供了新的见解。