内生真菌和内生细菌接种对雷公藤生长和次生代谢产物积累的影响

Effects of Inoculation with Endophytic Fungi and Endophytic Bacteria on Growth and Accumulation of Secondary Metabolites in Tripterygium wilfordii

摘要:

为探究内生真菌与内生细菌对雷公藤（Tripterygium wilfordii）的生长和次生代谢产物积累的相互作用，用内生真菌NS33、NS6和内生细菌LG3、LY1单独或跨界联合接种雷公藤，对雷公藤的生长和雷公藤甲素、雷公藤红素合成进行了研究。结果表明，单独或混合培养的菌株具有分泌铁载体、吲哚乙酸（IAA）和溶磷能力，对种子萌发、芽伸长和根系活力有显著促进作用。接种菌株NS33、NS6、NS6-LG3和NS6-LY1均显著促进了雷公藤组培苗的生长。单独或联合接种菌株均能显著提高雷公藤组培苗雷公藤甲素和雷公藤红素的积累，其中NS33-LG3和LG3的作用最显著。菌株NS33与LG3能够协同促进IAA的分泌、小麦幼苗根系活力和雷公藤红素的积累；菌株NS6与LY1协同提高了雷公藤组培苗的高度、质量和雷公藤红素的积累。因此，内生真菌与内生细菌联合接种对雷公藤生长和次生代谢产物积累具有一定的协同效应，显示出实际应用潜力。

Abstract:

In order to explore the interaction of endophytic fungi and endophytic bacteria on the growth and secondary metabolite accumulation of Tripterygium wilfordii, the endophytic fungi, Fusarium oxysporum NS33 and Penicillium steckii NS6, and endophytic bacteria, Enterobacter cloacae LG3 and Serratia marcescens LY1 were single or combined inoculated into the seedlings of T. wilfordii, and the seedling growth and synthesis of triptolide and celastrol were studied. The results showed that the strains cultured alone or in combination had the ability to secrete siderophore and indole acetic acid (IAA) and dissolve phosphate, and the seed germination rate, elongation of embryo and radicle, and root vigor were significantly promoted. The growth of T. wilfordii plantlets inoculated with strain NS33, NS6, NS6-LG3 or NS6-LY1 was significantly improved. The singe or combined inoculations could significantly enhance the accumulation of triptolide and celastrol, and NS33-LG3 and LG3 showed the greatest effects. Strain NS33 and LG3 could synergistically promote IAA secretion, root activity of wheat seedlings and celastrol accumulation. Strain NS6 and LY1 synergistically improved the height and weight of T. wilfordii plantlets and also celastrol accumulation. So, it was suggested that the combined inoculation of endophytic fungi and endophytic bacteria had a certain synergistic effects on the growth and secondary metabolite accumulation, showing a potential of practical application for T. wilfordii.