3. Results
3.1. Iturin A induces plant defense response through SA and JA
signaling pathways
PR1 and PDF1.2 gene expression was induced in the iturin A
treated leaves of wild plants (Fig. 1), suggesting that iturin A
induced LAR. PR1 (Fig. 1A) and PDF1.2 (Fig. 1B) gene expression was
acutely increased 6 h after treatment of the leaves with iturin A.
Similarly, the transient upregulation of PR1 gene expression was
confirmed in the iturin A treated leaves of atmyc2 mutant. In npr1-5
mutant, PR1 gene expression was not upregulated in response to
the iturin A treatment. In contrast, PDF1.2 gene expression was
upregulated 6 h after iturin A treatment of the leaves of npr1-5
mutant, but this upregulation was not observed in atmyc2 mutant.
In our previous study, we demonstrated that iturin A induced
SAR in strawberry plants, conferring defense resistance to fungal
pathogens [4]. In the present study, we confirmed that iturin A
induced SAR in Arabidopsis plants (Fig. 2). PR1 gene expression was
increased in iturin A untreated leaves of wild plants 72 h after
exposure to iturin A (Fig. 2A). A similar upregulation of PR1 gene
expression was observed in the untreated leaves of atmyc2 mutant.