Systemin/Jasmonate-mediated systemic defense signaling in tomato

Area of Science:

• Plant biology
• Molecular signaling
• Biochemistry

Background:

• Wound-inducible proteinase inhibitors (PIs) in tomato plants model systemic defense signaling.
• Systemin and jasmonic acid (JA) are proposed intercellular signals for wound-induced PIs expression.
• The interaction of systemin and JA in long-distance cell-to-cell communication remains unclear.

Purpose of the Study:

• To investigate the interaction between systemin and JA signaling pathways in tomato plants.
• To elucidate the mechanism of peptide and oxylipin signal interaction in coordinating systemic defense gene expression.
• To understand the roles of systemin and JA in plant defense to biotic stress.

Main Methods:

• Genetic analysis of the systemin/JA signaling pathway in tomato mutants.
• Grafting experiments with tomato mutants defective in JA biosynthesis and signaling.

Main Results:

• Evidence suggests jasmonic acid (JA), not systemin, functions as the systemic wound signal.
• Systemin regulates the biosynthesis of JA.
• Systemin and JA operate within the same signaling pathway to activate defense-related gene expression.

Conclusions:

• Jasmonic acid (JA) is identified as the primary long-distance mobile signal for plant defense responses.
• Systemin plays a regulatory role in JA biosynthesis, highlighting a coordinated signaling mechanism.
• Understanding the systemin/JA pathway offers insights into plant defense against biotic stress.