Riboflavin-Induced Disease Resistance Requires the Mitogen-Activated Protein Kinases 3 and 6 in Arabidopsis thaliana

Abstract

As a resistance elicitor, riboflavin (vitamin B2) protects plants against a wide range of pathogens. At molecular biological levels, it is important to elucidate the signaling pathways underlying the disease resistance induced by riboflavin. Here, riboflavin was tested to induce resistance against virulent Pseudomonas syringae pv. Tomato DC3000 (Pst DC3000) in Arabidopsis. Results showed that riboflavin induced disease resistance based on MAPK-dependent priming for the expression of PR1 gene. Riboflavin induced transient expression of PR1 gene. However, following Pst DC3000 inoculation, riboflavin potentiated stronger PR1 gene transcription. Further was suggested that the transcript levels of mitogen-activated protein kinases, MPK3 and MPK6, were primed under riboflavin. Upon infection by Pst DC3000, these two enzymes were more strongly activated. The elevated activation of both MPK3 and MPK6 was responsible for enhanced defense gene expression and resistance after riboflavin treatment. Moreover, riboflavin significantly reduced the transcript levels of MPK3 and MPK6 by application of AsA and BAPTA, an H2O2 scavenger and a calcium (Ca2+) scavenger, respectively. In conclusion, MPK3 and MPK6 were responsible for riboflavin-induced resistance, and played an important role in H2O2- and Ca2+-related signaling pathways, and this study could provide a new insight into the mechanistic study of riboflavin-induced defense responses.

Naringenin Induces Pathogen Resistance Against Pseudomonas syringae Through the Activation of NPR1 in Arabidopsis

“…In contrast, the induction of pathogen resistance by naringenin was not shown in mpk3 and mpk6 ( Figure 7 ). This observation is similar to a previous report that BTH, riboflavin and pipecolic acid induce pathogen resistance by increasing the activity of MPK3 and MPK6 ( Nie and Xu, 2016 ; Wang et al, 2018 ). These results suggest that naringenin also induces pathogen resistance through the activation of MAPK pathways.…”

“…SA-mediated immune responses are reported to be activated by the coordination of different NPR proteins ( Backer et al, 2019 ). It has been reported that pathogen resistance inducing molecules confer pathogen resistance in NPR1 dependent manner ( Nie and Xu, 2016 ; Yang et al, 2016 ). In this study, we showed that naringenin not only increased SA level by induction of SA biosynthetic gene ( Figures 3 , 4 ) but also induced nuclear translocation of NPR1 ( Figure 2 ).…”

MKK4/5-MPK3/6 Cascade Regulates Agrobacterium-Mediated Transformation by Modulating Plant Immunity in Arabidopsis

“…As a plant pathogen, Agrobacterium triggers plant immunity characterized by MPK3/MKK6 activation, and defense-responsive gene induction ( Figure 1 ). This process is similar to the responses to other plant pathogens such as Pst DC3000 (Nie and Xu, 2016 ).…”

Abscisic acid mediation of drought priming‐enhanced heat tolerance in tall fescue (Festuca arundinacea) and Arabidopsis

“…Several members of the MAPK family have been shown to be directly activated by the ABA signaling pathway (de Zelicourt et al ). The activation of MPKs was proved to be responsible for the enhanced expression of defense related genes and the subsequent enhanced stress resistance (Beckers et al , Nie and Xu , Mauch‐Mani et al ). In the present study, drought priming led to an upregulation of both FaMPK3 and FaMPK6 ; however, FaMPK6 was not affected by ABA (Fig.…”