# Transcriptomic Analysis of the Negative Effect of Epigallocatechin-3-Gallate from Tea Plant (Camellia sinensis) on Agrobacterium-Mediated Transformation Efficiency

## TL;DR

This study explores how a compound from tea plants, EGCG, reduces the efficiency of a common plant genetic modification method by affecting bacteria involved in the process.

## Contribution

The study identifies molecular mechanisms by which EGCG impairs Agrobacterium transformation efficiency using transcriptomic analysis and WGCNA.

## Key findings

- EGCG at 0.4 mg/mL nearly eliminated Agrobacterium transformation efficiency in tobacco.
- EGCG treatment increased malondialdehyde content in Agrobacterium.
- DEGs related to flagellar synthesis and secretion systems were down-regulated under EGCG stress.

## Abstract

Agrobacterium-mediated transformation is a widely used method for plant genetic modification. However, its efficiency in tea plants is notably low, and the underlying molecular mechanisms remain unclear, hindering advancements in the molecular breeding and biology of tea plants. In this study, tobacco was utilized as a model to investigate the effects of various concentrations of epigallocatechin-3-gallate (EGCG) on Agrobacterium transformation efficiency. The results demonstrated that at an EGCG concentration of 0.4 mg/mL, Agrobacterium nearly lost its ability to transform tobacco. Additionally, malondialdehyde content in Agrobacterium was measured before and after EGCG treatment. The findings indicated that EGCG treatment led to an increase in malondialdehyde content. Transcriptome sequencing analysis revealed that differentially expressed genes (DEGs) involved in Agrobacterium flagellar synthesis and secretion systems were down-regulated under EGCG stress. Furthermore, flgE, virB4, and virB6 were identified as hub genes through weighted gene co-expression network analysis (WGCNA). These results elucidate the dynamic mechanisms by which EGCG affects Agrobacterium at both the physicochemical and molecular levels, providing a theoretical basis for optimizing genetic transformation in tea plants.