# Diversity and Correlation Analysis of Differential Amino Acid Metabolites and Dominant Endophytic Bacteria in Lycium chinense Fruits at Different Stages

## TL;DR

This study explores how amino acid metabolites and dominant bacteria in Lycium chinense fruits change during different growth stages and how they are related.

## Contribution

The study identifies specific genes and bacteria linked to amino acid metabolism in Lycium chinense fruits at different developmental stages.

## Key findings

- Five dominant endophytic bacterial genera were identified in Lycium chinense fruits across three developmental stages.
- Four bacterial genera showed positive and negative correlations with various amino acid metabolites.
- Five genes were found to regulate key amino acid metabolic pathways in the fruits.

## Abstract

Background: Lycium chinense has been acknowledged for its substantial nutritional benefits. The “Mengqi No.1” variety of L. chinense is known for its high yield and exceptional quality. Methods: We screened twenty dominant endophytic bacterial genera based on OTUs from L. chinense fruits during three developmental stages. Results: Forty-three differential amino acid metabolites were selected from L. chinense fruits. Five endophytic bacteria (Enterococcus, Escherichia-Shigella, Bacteroides, Pseudomonas, and Bacillus) were dominant genera in green fruit (GF, 16–19 days after flowering), color-changing fruit (CCF, 22–25 days after flowering), and red-ripe fruit (RRF, 31–34 days after flowering). Four endophytic bacterial genera (Enterococcus, Bacillus, Pseudomonas, and Rhodanobacter) showed positive correlation with twenty different amino acid metabolites and negative correlation with seven different amino acid metabolites. Conclusions: Five genes (AST1, ltaE1, TAT1, SHMT2, and SHMT3) indicated positive correlation with seventeen different amino acid metabolites and negative correlation with eight different amino acid metabolites. AST1 gene had a major role in regulating arginine biosynthesis (ko00220); ltaE1, SHMT2, and SHMT3 genes were major in regulating glycine, serine, and threonine metabolism (ko00260); and TAT1 gene had a major role in regulating tyrosine metabolism (ko00350). These findings offer insights into the relationship between amino acid synthesis and endophytic bacteria in L. chinense fruits.