Abstract
Green tea is a widely-consumed healthy drink produced from the leaves of Camellia sinensis. It is renowned for its antioxidant and anticarcinogenic properties, but also displays significant antimicrobial activity against numerous human pathogens. Here we analyzed the antimicrobial activity of Gunpowder green tea against Pseudomonas syringae pv. actinidiae (Psa), the agent that causes kiwifruit bacterial canker. At the phenotypic level, tea extracts strongly inhibited Psa growth and swimming motility, suggesting it could reduce Psa epiphytic survival during plant colonization. The loss of bacterial virulence-related traits following treatment with tea extracts was also investigated by large-scale transcriptome analysis, which confirmed the in vitro phenotypes and revealed the induction of adaptive responses in the treated bacteria allowing them to cope with iron deficiency and oxidative stress. Such molecular changes may account for the ability of Gunpowder green tea to protect kiwifruit against Psa infection.
Highlights
Tea is produced from the leaves of Camellia sinensis L
Psa cultivated for 24 h in liquid King’s B (KB) medium supplemented with different concentrations of tea showed significant growth inhibition compared to the control with no tea (Figure 1C)
To determine whether the lower OD600 was due to bactericidal or bacteriostatic effects, the same Psa cultures grown overnight in the presence of different concentrations of tea were plated to determine the cfu/ml (Figure 1D). This revealed that the presence of tea at an epigallocatechin gallate (EGCG) concentration of 0.8 mg/ml significantly inhibited bacterial growth kinetics but did not kill the bacteria, which were still viable at the end of the experiment, with approximately the same cell number as the initial inoculum
Summary
Tea is produced from the leaves of Camellia sinensis L. Green tea is a non-fermented tea with a high catechin content, typically consumed in China and Japan but increasingly popular worldwide. It is associated with health benefits such as protection against cancer and cardiovascular disease (Cabrera et al, 2006). The activity of tea catechins against plant pathogens has not been studied in detail and the mechanism of action is unclear (Yang and Zhang, 2019). There is evidence that tea catechins help to prevent infections by Tobacco mosaic virus and Cucumber mosaic virus (Okada, 1971), as well as the bacterial pathogens Xanthomonas campestris pv. There is evidence that tea catechins help to prevent infections by Tobacco mosaic virus and Cucumber mosaic virus (Okada, 1971), as well as the bacterial pathogens Xanthomonas campestris pv. citri and Gunpowder Green Tea Inhibits Psa Virulence pv. vesicatoria, and Pseudomonas syringae pv. tomato, which infect citrus and tomato, respectively (Kodama et al, 1991; Lo and Zhao, 2015)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
