Abstract：
Trichoderma spp. are an important plant-growth-promoting fungi. Trichoderma citrinoviride HT-1 was isolated from Rheum palmatum root, which has beneficial effects on growth and metabolite accumulation. However, the improvement mechanisms for growth and metabolite accumulation of T. citrinoviride HT-1 are unclear. In this study, RNA sequencing (RNA-seq) and high-performance liquid chromatography (HPLC) were used to measure the effect of different concentrations of conidial suspension of the HT-1 strain on the growth promotion and metabolite accumulation of R. palmatum seedlings. The results showed that the highest biomass and metabolites of R. palmatum seedlings were obtained through treatment with the HT-1 strain at a final spore concentration of 107 spores/mL. RNA sequencing indicated that 1662 genes were upregulated and 2155 genes were downregulated after inoculation with 107 spores/mL of the HT-1 strain. This strain induced significant upregulation of related genes in the phenylpropanoid biosynthesis pathway, plant hormone signal transduction pathway, biosynthesis of secondary metabolites pathway, and plant-pathogen interaction pathway in R. palmatum. The gene expression trends were revealed through quantitative real-time polymerase chain reaction (qRT-PCR) and were consistent with those determined by RNA-seq. Our results will help us to understand the growth-promoting mechanisms of the HT-1 strain on R. palmatum and provide a theoretical basis for the application of T. citrinoviride HT-1 as a biological fertilizer.
摘要：
木霉属。是一种重要的促进植物生长的真菌。从掌叶大黄根中分离出衣木霉HT-1，对生长和代谢物积累有有益的影响。然而,目前尚不清楚甜叶菊HT-1生长和代谢产物积累的改善机制。在这项研究中,采用RNA测序(RNA-seq)和高效液相色谱法(HPLC)测定了不同浓度的HT-1菌株分生孢子混悬液对掌叶草幼苗生长和代谢产物积累的影响。结果表明，在最终孢子浓度为107个孢子/mL的条件下，用HT-1菌株处理掌叶草幼苗的生物量和代谢产物最高。RNA测序表明，接种107个孢子/mL的HT-1菌株后，1662个基因上调，2155个基因下调。该菌株诱导苯丙素生物合成途径相关基因显著上调，植物激素信号转导途径,次级代谢产物的生物合成途径，和植物-病原体相互作用途径。通过定量实时聚合酶链反应（qRT-PCR）揭示了基因表达趋势，并且与通过RNA-seq确定的趋势一致。我们的研究结果将有助于我们了解HT-1菌株在掌叶草上的生长促进机制，并为金雀花HT-1作为生物肥料的应用提供理论依据。
