College of Agronomy, Yunnan Key Laboratory of Konjac Biology, Yunnan Urban Agricultural Engineering and Technological Research Center, Kunming University, Kunming, 650214, China.
Sci Rep. 2024 Nov 18;14(1):28432. doi: 10.1038/s41598-024-79850-w.
Konjac seeds of Amorphophallus muelleri are produced through a unique form of apomixis in triploid parthenogenesis, and typically require a longer maturation period (approximately 8 months). To date, the relevant functions of endophytic microbial taxa during A. muelleri seed development and maturation remain largely unexplored. In this study, we analyzed the functional adaptability and temporal dynamics of endophytic microbial communities during three stages of A. muelleri seed maturation. Through metagenomic sequencing, we determined that the functions of the endophytic microbiome in A. muelleri seeds were driven by the seed maturation status, and the functions of the microbial communities in the seed coats and seeds differed significantly. The species annotation results show that Proteobacteria, Actinobacteria, Ascomycota, and Basidiomycota were the dominant bacterial and fungal communities in A. muelleri seeds at different maturation stages. The KEGG and COG functional gene annotation results revealed that the seed samples during the three maturation stages had higher KO functional diversity than the seed coat samples, and the COG functional diversity of the green and red seed samples was also significantly higher than that of the seed coat samples. At different maturation stages, microbial functional genes involved in energy production and conversion as well as carbon fixation were enriched in the A. muelleri seed coats, while microbial functional genes involved in signal transduction mechanisms, amino acid transport and metabolism, carbohydrate metabolism, and lipid metabolism were more highly expressed in the seeds. Moreover, in the middle to late stages of seed maturation, the microbial functional genes involved in the biosynthesis of resistant compounds such as phenols, flavonoids, and alkaloids were significantly enriched to enhance the resistance and environmental adaptation of A. muelleri seeds. The results verified that the functions of the endophytic microbial communities change dynamically during A. muelleri seed maturation to adapt to the current needs of the host plant, which has significant implications for the exploration and utilization of functional microbial resources in A. muelleri seeds.
魔芋的种子是通过三倍体孤雌生殖中的独特无融合生殖形式产生的，通常需要更长的成熟时间（约 8 个月）。迄今为止，内生微生物类群在魔芋种子发育和成熟过程中的相关功能在很大程度上仍未得到探索。在这项研究中，我们分析了魔芋种子成熟过程中三个阶段内生微生物群落的功能适应性和时间动态。通过宏基因组测序，我们确定了魔芋种子内生微生物组的功能是由种子成熟状态驱动的，种皮和种子中的微生物群落的功能有很大差异。物种注释结果表明，在不同成熟阶段的魔芋种子中，厚壁菌门、放线菌门、子囊菌门和担子菌门是主要的细菌和真菌群落。KEGG 和 COG 功能基因注释结果表明，在三个成熟阶段的种子样本中，KO 功能多样性高于种皮样本，而绿、红种子样本的 COG 功能多样性也明显高于种皮样本。在不同的成熟阶段，参与能量产生和转化以及碳固定的微生物功能基因在魔芋种皮中富集，而参与信号转导机制、氨基酸运输和代谢、碳水化合物代谢和脂质代谢的微生物功能基因在种子中表达水平更高。此外，在种子成熟的中后期，参与合成酚类、类黄酮和生物碱等抗性化合物的微生物功能基因明显富集，以增强魔芋种子的抗性和环境适应性。研究结果证实，在魔芋种子成熟过程中，内生微生物群落的功能是动态变化的，以适应宿主植物的当前需求，这对探索和利用魔芋种子中的功能微生物资源具有重要意义。
