Promotion of phenolic compounds production in Salvia miltiorrhiza hairy roots by six strains of rhizosphere bacteria

Abstract

Salvia miltiorrhiza Bunge is an important herb for the treatment of cerebrovascular and cardiovascular diseases with bioactive compounds (phenolic acids and tanshinones). Abundant studies showed that tanshinones could be stimulated by biotic and abiotic stresses, but limited information is available on biosynthesis of phenolic acids promoted by biotic stresses. The aim of the present work was to isolate and identify rhizosphere bacteria which stimulated phenolic compound in Salvia miltiorrhiza hairy roots and investigated the internal mechanism, providing a potential means to enhance content of pharmaceuticals in S. miltiorrhiza. The results showed that six bacteria, namely, HYR1, HYR26, SCR22, 14DSR23, DS6, and LNHR13, belonging to the genus Pseudomonas and Pantoea, significantly promoted the growth and content of major phenolic acids, RA and SAB. Bacteria LNHR13 was the most effective one, with the contents of RA and SAB reaching ∼2.5‐fold (30.1 mg/g DW) and ∼2.3‐fold (48.3 mg/g DW) as those of the control, respectively. Phytohormones and polysaccharides produced by bacteria showed potential responsibility for the growth and biosynthesis of secondary metabolites of S. miltiorrhiza. Meanwhile, we found that the more abundant the types and contents of phytohormones, the stronger their stimulating effect on the content of salvianolic acids.

SmSPL6 Induces Phenolic Acid Biosynthesis and Affects Root Development in Salvia miltiorrhiza

“…Previous reports have shown that several elicitors influence the production of phenolic acids [ 34 ]. These elicitors can be divided into two groups (biotic and abiotic), with the former containing both pathogenic and plant cell components [ 35 , 36 ], and the latter including Ag + [ 37 ], MeJA [ 6 ], SA [ 38 ], etc. Elicitors can affect phenolic acid compounds via transcription factors, which activate or repress the expression of enzyme genes that are engaged in the phenolic acid biosynthetic pathway.…”

Insights into the mechanism of the effects of rhizosphere microorganisms on the quality of authentic Angelica sinensis under different soil microenvironments

“…and Pantoea sp. in the rhizosphere could stimulate the plant growth and synthesize of major phenolic acids in Salvia miltiorrhiza through its production of the abundant types and contents of phytohormones [ 54 ]. Elsewhere, inoculation of Trichoderma asperellum significantly increased the artemisinin concentration and dry weight of Artemisia annua L. leaves through elevated expression of artemisinin biosynthesis crucial enzymatic genes, HMGR1 , FPS , ADS , CYP71AV1 , CPR , DBR , DXS1, and DXR1 [ 55 ].…”

Trichoderma harzianum prevents red kidney bean root rot by increasing plant antioxidant enzyme activity and regulating the rhizosphere microbial community

“…Whereas the relative abundance of Porphyrobacter (ASV 46), Lysobacter (ASV 85), Microbacteriaceae (ASV 105), and Gemmatimonas (ASV 107) was significantly ( p < 0.05) higher in T891 + Fu13 compared to Fu13. Porphyrobacter has been reported to be a dominant group of bacteria with degrading ability ( Hiraishi et al, 2002 ), Lysobacter is a biocontrol bacterium with great potential ( Islam, 2010 ; Zhao et al, 2017 ), Microbacteriaceae have been shown to promote weight gain in Salvia miltiorrhiza hairy roots ( You et al, 2018 ), Gemmatimonas can accelerate the nitrogen cycle and aggregate phosphate, thereby promoting plant growth ( Zhang et al, 2023b ). Randomized forest results also showed that Porphyrobacter (ASV 46) and Lysobacter (ASV 85) were the primary influencing factors ( p < 0.05) on plant disease incidence and growth, respectively.…”