School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou 310053, PR China.
School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou 310053, PR China.
Int J Biol Macromol. 2024 Aug;274(Pt 2):133343. doi: 10.1016/j.ijbiomac.2024.133343. Epub 2024 Jun 24.
Endophytic fungi can promote plant growth and development, particularly of Orchidaceae species. Previously, we found that the endophytic fungus Phyllosticta fallopiae DN14, collected from Dendrobium nobile growing on rocks in a wild habitat, significantly promoted growth of its host plant D. nobile, an important herb in Chinese traditional medicine that contains the bioactive component dendrobine. Phyllosticta was positively correlated with FW and dendrobine content of D. nobile and with Si content of the epiphytic matrix. Si is also highly beneficial for the growth and productivity of many plants. Here, we co-cultured D. nobile with P. fallopiae DN14 in half-strength Murashige and Skoog medium with and without various concentrations of Si to investigate the effects of DN14 and Si on plant fresh weight and dendrobine content. We also explored the effects of DN14 infection and colonization on host plant growth, Si accumulation and transport, and expression of key genes, as well as the interaction between DN14 and Si. The combination of DN14 and Si promoted the lignification of D. nobile roots, stems, and leaves and markedly increased the thickening of xylem cell walls. Co-culture with DN14 increased transport of Si from roots to stems and from stems to leaves. Transcriptome sequencing and qRT-PCR analyses showed that enhancement of D. nobile growth by DN14 and Si may involve upregulation of plant hormone-related genes (AUX/IAA and MYC) and lignin biosynthesis genes (HCT, PAL1, and PAL2). Insoluble Si promoted the growth of DN14, perhaps through downregulation of genes (e.g., FBP, MPI, RPIAD) related to carbohydrate metabolism, and DN14 in turn promoted the transformation of insoluble Si into soluble Si for plant uptake. These findings demonstrate that endophytic fungi and Si can improve the growth of D. nobile and therefore show promise as organic amendments for commercial cultivation.
内生真菌可以促进植物的生长和发育，特别是兰科植物的生长和发育。以前，我们发现内生真菌 Phyllosticta fallopiae DN14，从生长在野外生境岩石上的铁皮石斛中分离得到，可显著促进其宿主铁皮石斛的生长，铁皮石斛是中国传统医学中的一种重要草药，含有生物活性成分石斛碱。Phyllosticta 与铁皮石斛的 FW 和石斛碱含量以及附生基质中的 Si 含量呈正相关。Si 对许多植物的生长和生产力也非常有益。在这里，我们在半强度 Murashige 和 Skoog 培养基中与 P. fallopiae DN14 共同培养铁皮石斛，培养基中有无不同浓度的 Si，以研究 DN14 和 Si 对植物鲜重和石斛碱含量的影响。我们还探索了 DN14 感染和定植对宿主植物生长、Si 积累和运输以及关键基因表达的影响，以及 DN14 和 Si 之间的相互作用。DN14 和 Si 的组合促进了铁皮石斛根、茎和叶的木质化，并显著增加了木质部细胞壁的增厚。共培养与 DN14 增加了 Si 从根部向茎部和从茎部向叶片的运输。转录组测序和 qRT-PCR 分析表明，DN14 和 Si 对铁皮石斛生长的促进作用可能涉及植物激素相关基因（AUX/IAA 和 MYC）和木质素生物合成基因（HCT、PAL1 和 PAL2）的上调。不溶性 Si 促进了 DN14 的生长，这可能是通过下调与碳水化合物代谢相关的基因（如 FBP、MPI、RPIAD）实现的，而 DN14 反过来又促进了不溶性 Si 向植物可吸收的可溶性 Si 的转化。这些发现表明，内生真菌和 Si 可以改善铁皮石斛的生长，因此有望作为商业栽培的有机肥料。
