NanoClay-enhanced spray-induced gene silencing as a biological control strategy for Rehmannia glutinosa root rot disease.

Abstract

BACKGROUND Rehmannia glutinosa, a herb of significant medicinal and food value, is highly susceptible to pathogen infections. Fusarium oxysporum f.sp. R. glutinosa (FORg), a pathogenic strain isolated from R. glutinosa, induces root rot disease, leading to severe yield losses. Currently, resistant cultivars and effective control strategies for R. glutinosa root rot remain very limited. This study aims to investigate the feasibility and potential of SIGS technology in preventing and controlling R. glutinosa root rot caused by FORg. RESULTS This study demonstrates that FORg hyphae can capably take up dsRNA, confirming their suitability for SIGS-based disease control. dsRNA targeting SGE1 and CYP51, synthesized in vivo and extracted through low-cost ethanol method, significantly suppressed the expression of virulence-associated genes in both hyphae and conidia. Root disc assays further validated that exogenous dsRNA effectively attenuated FORg pathogenicity. Combined applications of SGE1 and CYP51S dsRNAs synergistically reduced disease severity compared to single-target treatments. Additionally, dsRNA encapsulated in layered double hydroxide (LDH) prolonged functional durability, with sustained plant protection observed for 15 days post-spraying, outperforming unencapsulated dsRNA. CONCLUSION This finding establishes the feasibility of SIGS for controlling FORg-induced root rot in R. glutinosa and highlights the potential of nanomaterial encapsulation in addressing persistent fungal epidemics in agricultural systems. © 2025 Society of Chemical Industry.