Effect of Pseudomonas Fluorescens Zl22 on Phenolic Acid Autotoxicants Stress in 40-Years Continuous Cropping Tea Plantation

The accumulation of p-hydroxybenzoic acid (PHBA), 3, 4 dihydroxybenzoic acid (PA) and cinnamic acid (CA) is a vital factor in the decline of the tea plantation ecological system. This study aimed to investigate the effect of ZL22 on in situ soil restoration and PAA regulation in a tea plantation. ZL22 was found to have the complete pathway to degrade PHBA and PA to acetyl CoA. ZL22 was able to efficiently degrade 99% of PHBA and 99% of PA after 3d and synergistically promoted lettuce growth with 50 mg/L CA. In situ application of ZL22 showed that compared to commercial P. fluorescens zym-ch0, ZL22 was able to efficiently colonize and continuously reduce PHBA and PA in tea rhizospheric soil. The presence of ZL22 and subsequent safe levels of CA significantly increased tea production. Meanwhile, the addition of ZL22 alleviated the inhibition of PAA on microbiota, increased the abundance of genera associated with cellulose degradation, nitrogen conversion, sulfur metabolism and created an optimum pH value, organic carbon and available N for secondary metabolite accumulation of tea leaves. The application of ZL22 managed the concentrations of PAA to a safe level in soil, which synergistically improved soil fertility, and thereby promoted tea quality.