PDF(Pubmed)
Abstract：
Indole acetic acid (IAA) is one of the prime communicator playing a chief role in the interaction between host plant and endophytes. IAA produced by the endophytes primarily contributes to plant growth and development. Here, we optimized IAA production by an endophytic fungus Diaporthe terebinthifolli GG3F6 isolated from the asymptomatic rhizome of Glycyrrhiza glabra employing response surface methodology (RSM) and exploring its effect on the host plant biology. The methodology revealed 1.1 fold increases in IAA accumulation. The maximum IAA (121.20 μg/mL) was achieved using tryptophan substrate (1 mg/mL) in Potato dextrose broth (48 g/L) adjusted to pH 12 and incubated at 35 °C for 7 days. The significantly low p-value (p < 0.0001) of the experiment propounded that the model best fits the experimental data, and the independent variables have considerable effects on the production of IAA. Morphologically, the in-vitro grown G. glabra plants showed enhanced root and shoot growth when co-cultivated with the isolated endophytic fungal strain (GG3F6) relative to the control plants. Also, the enhanced accumulation of total phenolic (10.7 %) and flavonoid (10.2 %) in the endophyte treated plants was observed. The optimization of IAA production by an endophytic fungus using (RSM) has not been reported so far. Interestingly, 2.1 fold increase in glycyrrhizin content was recorded in GG3F6 treated in-vitro host plants as compared to the control plants. This suggested a potential use of D. terebinthifolli as a biostimulator for plant and enhanced accumulation of glycyrrhizin. The study highlights the dynamic host-endophyte interaction for exploitation in agricultural and pharmaceutical applications.
摘要：
吲哚乙酸（IAA）是主要的传播者之一，在寄主植物与内生菌之间的相互作用中起着主要作用。内生菌产生的IAA主要有助于植物生长和发育。这里,我们使用响应面法（RSM）优化了从甘草无症状根茎中分离出的内生真菌DiaportheterebybenthifoliGG3F6的IAA生产，并探索了其对寄主植物生物学的影响。该方法显示IAA积累增加1.1倍。使用调至pH12的马铃薯葡萄糖肉汤(48g/L)中的色氨酸底物(lmg/mL)并在35°C下孵育7天,获得最大IAA(121.20μg/mL)。实验中p值明显较低(p<0.0001),表明该模型与实验数据的拟合效果最佳,自变量对IAA的产量有相当大的影响。形态学上,当与分离的内生真菌菌株（GG3F6）共培养时，相对于对照植物，体外生长的G.glabra植物显示出增强的根和芽生长。此外，在内生菌处理的植物中，观察到总酚（10.7％）和类黄酮（10.2％）的积累增强。迄今为止，尚未报道使用内生真菌（RSM）优化IAA生产的方法。有趣的是,与对照植物相比,在GG3F6处理的体外宿主植物中记录到甘草甜素含量增加2.1倍。这表明D.terebinthifoli可能用作植物的生物刺激剂，并增强了甘草甜素的积累。该研究强调了动态的宿主-内生菌相互作用，可用于农业和药物应用。
