Correlation in endophytic fungi community diversity and bioactive compounds of Sophora alopecuroides

Abstract

Sophora alopecuroides L. is a traditional Chinese medicine used for the treatment of several different disease states including bacillary dysentery and enteritis. But importantly, it also plays a role as an anti-tumor agent. That said, little is known about the role endophytes play regarding the clinically bioactive metabolites in S. alopecuroides. In order to explore the effects of endophytic fungi on the accumulation, quality, and correlation in the content of the medicinal compounds, the structural diversity of endophytic fungi in S. alopecuroides was analyzed. The relationship between endophytes and quinolizidine alkaloids (QAs), housed within the seeds of S. alopecuroides, which were interpreted based on established methods of high-throughput sequencing and high-performance liquid chromatography. A total of 1,034,418 effective sequence reads and 257 operational taxonomic units (OTUs) were obtained from 33 samples which were sourced from 11 different sampling sites and further classified into 9 phyla, 20 classes, 45 orders, 85 families, and 118 genera. Ascomycota was found to be the dominant phylum of endophytic fungi in S. alopecuroides, with a relative abundance ranging from 60.85 to 98.30%. Alternaria, Cladosporium, Filobasidium, and an unidentified Ascomycota were the core-shared endophytes, accounting for 49.96, 27.12, 14.83, and 7.88%, respectively. Correlation analysis showed that the Simpson’s diversity index of endophytic fungal community in S. alopecuroides was significantly positively correlated with the Oxymatrine (OMA) content in different areas, while the Chao and Shannoneven indexes were significantly negatively correlated with OMA. The endophytic fungi of Alternaria were positively correlated with the content of OMA, Oxysophocarpine (OSC), and total QAs. This study has mastered the endophytic fungi resources of S. alopecuroides, explored potential functional endophytic fungi, and provided a scientific basis for using biological fertilization strategies to improve the quality of S. alopecuroides.

The Endophytic Fungi Diversity, Community Structure, and Ecological Function Prediction of Sophora alopecuroides in Ningxia, China

“…Unclassified Ascomycota, Alternaria, and Aspergillus are the dominant genera in S. alopecuroides, which were common in all four organs as well. It is reported that plant fungi are mainly composed of Ascomycota [20,32], which is consistent with the result that unclassified Ascomycota is the dominant genera in this study. Ascomycota fungi have higher species diversity due to their faster evolutionary rate and adaptability [75].…”

“…Likewise, Alternaria has great potential in the biological control of plant diseases [84]. Ju et al [32] found that specific endophytic fungi play a key role in the accumulation of bioactive compounds in the internal environment of S. alopecuroides seeds, and Alternaria in S. alopecuroides can promote the production of quinolizidine alkaloids (QAs) in the host. Endophytic fungi of S. alopecuroides have rich diversity.…”

“…The paired-end reads from sequencing were assigned to respective samples using Cutadapt software [38] based on their specificity. Barcode and primer sequences were truncated from these reads [32]. To avoid mixing samples, specific primer-based barcodes were assigned to each sample at the start and end of sequencing [39].…”

“…Liang et al [31] revealed that the accumulation of pharmacological components in Codonopsis pilosula were related to the dynamic changes of endophytes, and further culture-dependent experiments validated that endophytes participated in the accumulation of metabolites. In the early stage, our research team used HTS to analyze the diversity of endophytic fungi of S. alopecuroides seeds in different geographical populations in China [32] and we hypothesized that endophytic fungi of S. alopecuroides in different organs are also diverse and have ecological functions.…”

Diversity and correlation analysis of endophytes and metabolites of Panax quinquefolius L. in various tissues

“…Highly-diverse endophytic communities can greatly influence the metabolite composition of host plants [ 16 ]. Studies on Ginkgo biloba L. found that endophytic bacteria were significantly correlated with flavonoid concentration and composition.In particular, Staphylococcus was positively correlated with quercetin and variations in the abundance of Staphylococcus showed a strong correlation with flavonoid content [ 17 ].…”