Abstract
Extensive use of chemical control agents and fungicides typically leads to numerous risks to human health and the environment. Using plant extracts as natural substances represents a dual key for the environment and sustainable food production, as it reduces the input of synthetic pesticides into the environment and/or controls plant pathogens. For the first time, a
Plantago lagopus
ethanolic extract has been characterized and evaluated for its protective and curative effects against
Rhizoctonia solani
in tomato plants. The results showed that
P. lagopus
extract (10 μg/ml) completely inhibited
R. solani
mycelial growth
in vitro
. At 20 days of post fungal inoculation, the results demonstrated that using
P. lagopus
extract (100 μg/ml)
in vivo
enhanced tomato plant growth by significantly increasing shoot and root parameters in protective and curative treatments. Furthermore, the protective and curative treatments significantly reduced the disease index by 18.66 and 38.66%, respectively. Induction of systemic resistance with upregulation of
PR-1
and
PR-2
and a significant increase in the transcriptional levels of
PR-3
and
CHS
in all
P. lagopus
extract-treated tomato plants were reported compared to untreated plants. HPLC analysis showed that the most common polyphenolic components detected in
P. lagopus
extract were rutin (74206.3 mg/kg), naringenin (2388.74 mg/kg), quercetin (1249.13 mg/kg), and
p
-hydroxybenzoic acid (1035.87 mg/kg). In addition, the ellagic acid (798.47 mg/kg), vanillic acid (752.55 mg/kg), catechol (648.89 mg/kg), cinnamic acid (332.51 mg/kg), ferulic acid (296.32 mg/kg), benzoic acid (295.95 mg/kg), and chlorogenic acid (116.63 mg/kg) were also reported. Our study is the first to show that
P. lagopus
extract can help plants fight off
R. solani
fungal infection. Furthermore, the findings imply that using the
P. lagopus
extract as a natural biocontrol agent could be a sustainable strategy to manage plant fungal diseases.