CONCLUSION
In conclusion, we demonstrated that the WRK33 transcription factor can
act as a core regulator of AR156-induced ISR resistance against
different lifestyles pathogens (Figure 7). In Arabidopsis , AR156
colonizes in Arabidopsis roots, inducing ISR signaling, and the
signals are transferred to the leaves. WRKY33 , a positive
regulator of AR156-induced systemic resistance, was upregulated by AR156
induced. AR156 regulated the expression of CYP71A13 andPAD3 through WRKY33 thereby increasing the intracellular
accumulation of camalexin upon infection with different pathogens. On
the other hand, AR156 relied on PEN3 and PDR12 to transfer camalexin
accumulated outside the cell to protect against different pathogens. Our
study firstly raises that WRKY33 is involved in regulating the
accumulation and secretion of phytoalexin induced by AR156 as a core
factor. In addition, our study systematically elucidates the mechanism
of PGPR-triggered ISR resistance to broad-spectrum pathogens and offers
a theoretical basis for developing and applying new biopesticides.