Naringenin confers defence against Phytophthora nicotianae through antimicrobial activity and induction of pathogen resistance in tobacco

Abstract

Tobacco black shank caused by Phytophthora nicotianae is a serious disease in tobacco cultivation. We found that naringenin is a key factor that causes different sensitivity to P. nicotianae between resistant and susceptible tobacco. The level of basal flavonoids in resistant tobacco was distinct from that in susceptible tobacco. Of all flavonoids with different content, naringenin showed the best antimicrobial activity against mycelial growth and sporangia production of P. nicotianae in vitro. However, naringenin showed very low or no antimicrobial activity to other plant pathogens.We found that naringenin induced not only the accumulation of reactive oxygen species, but also the expression of salicylic acid biosynthesis-related genes. Naringenin induced the expression of the basal pathogen resistance gene PR1 and the SAR8.2 gene that contributes to plant resistance to P. nicotianae. We then interfered with the expression of the chalcone synthase (NtCHS) gene, the key gene of the naringenin synthesis pathway, to inhibit naringenin biosynthesis. NtCHS-RNAi rendered tobacco highly sensitive to P. nicotianae, but there was no change in susceptibility to another plant pathogen, Ralstonia solanacearum. Finally, exogenous application of naringenin on susceptible tobacco enhanced resistance to P. nicotianae and naringenin was very stable in this environment. Our findings revealed that naringenin plays a core role in the defence against P. nicotianae and expanded the possibilities for the application of plant secondary metabolites in the control of P. nicotianae.

Xanthomonas oryzaepv.oryzaetype-III effector TAL9b targets a broadly conserved disease susceptibility locus to promote pathogenesis in rice

“…Further, the accumulation of naringenin was shown to provide broad-spectrum resistance to rice pests (Yang et al, 2021). Additionally, naringenin was found to possess antimicrobial and defense-inducing properties in other plant species like tobacco and Arabidopsis (An et al, 2021; Shi et al, 2024; Sun et al, 2022). Therefore, it can be speculated that reducing the basal level of naringenin during pathogenesis, possibly mediated by the induction of OsS5H/FNS-03g will aid in rendering the host environment conducive for pathogen growth.…”

Comparative transcriptome and metabolome analyses of cherry leaves spot disease caused by Alternaria alternata

“…The up-regulation of CHS and FLS, as well as flavonoid accumulation, played a positive role in the resistance of cherry to A. alternata . The ROS scavenging capacity of flavonoids has been proposed to protect against pathogens, including Sclerotinia sclerotiorum ( Ranjan et al., 2019 ) and Phytophthora nicotianae ( Sun et al., 2022 ). These mechanisms may confer resistance against A. alternata in cherry.…”

Flavonoids Are Intra- and Inter-Kingdom Modulator Signals

“…Another promising flavonoid for field application is naringenin, although its involvement in plant defense is poorly elucidated. A preliminary study in tobacco highlights that naringenin is endowed with a low-medium antifungal activity against Phytophtora nicotianae, although it induces the expression of salicylic acid responses to counteract the pathogen attack [298].…”