Fabrication of Isopropanolamine-Decorated Coumarin Derivatives as Novel Quorum Sensing Inhibitors to Suppress Plant Bacterial Disease

Abstract

Emerging pesticide-resistant phytopathogenic bacteria have become a stumbling block in the development and use of pesticides. Quorum sensing (QS) blockers, which interfere with bacterial virulence gene expression, are a compelling way to manage plant bacterial disease without resistance. Herein, a series of isopropanolamine-decorated coumarin derivatives were designed and synthesized, and their potency in interfering with QS was investigated. Notably, compound A 5 exhibited a better bioactivity with median effective concentration (EC 50 ) values of 6.75 mg L −1 against Xanthomonas oryzae pv. oryzae (Xoo) than bismerthiazol (EC 50 = 21.9 mg L −1 ). Further biochemical studies revealed that compound A 5 disturbed biofilm formation and suppressed bacterial virulence factors and so forth. Moreover, compound A 5 decreased the expression of QS-related genes. Interestingly, compound A 5 had the acceptable control effect (53.2%) toward Xoo in vivo. Overall, this study identifies a novel lead compound for the development of bactericide candidates to control plant bacterial diseases by interfering with QS.

New Inspiration of 1,3,4-Oxadiazole Agrochemical Candidates: Manipulation of a Type III Secretion System-Induced Bacterial Starvation Mechanism to Prevent Plant Bacterial Diseases

“…It also exhibited better protective efficiency (43.2%) than the commercial bactericide BT (33.9%). Meanwhile, the toxicological evaluation of compound C 7 on rice plants after treating for 7 days at 200 μg/mL was executed . The results showed that compound C 7 was non-toxic to rice under the tested concentrations (see Figure S1).…”

“…Meanwhile, the toxicological evaluation of compound C 7 on rice plants after treating for 7 days at 200 μg/mL was executed. 38 The results showed that compound C 7 was nontoxic to rice under the tested concentrations (see Figure S1). These findings indicated that compound C 7 was a valuable candidate with low toxicity for further development.…”

“…oryzae pv. oryzae ( Xoo ), Xanthomonas axonopodis pv citri ( Xac ), and Pseudomonas syringae pv actinidiae ( Psa ) have been studied. , Further action mechanisms indicated that these highly active compounds are potential virulence factor inhibitors that could hamper pathogenicity without affecting the survival rate of Xoo , which will be useful for managing bacterial diseases. , Therefore, fabricating new 1,3,4-oxadiazole derivatives with a piperidyl-linked β-amino alcohol moiety may lead to the discovery of promising T3SS inhibitors to prevent plant bacterial diseases.…”

Research on Diffusible Signal Factor-Mediated Quorum Sensing in Xanthomonas: A Mini-Review

“… Srilatha et al [ 62 ] Coumarin derivative Synthesis based on derivation of natural product Disturbed biofilm formation; suppressed bacterial virulence factors and production of DSF; reduced expression of rpfF gene. Feng et al [ 64 ] …”

“…In 2022, a series of coumarin derivatives containing isopropanolamine units were designed as anti-QS agents and evaluated for their QS interference ability [ 64 ]. After a treatment with compound 6 , the results revealed a marked decrease in significant virulence factors, including biofilm formation, bacterial motility, levels of extracellular enzymes, and a notable reduction in DSF signal production and rpfF gene expression.…”