The jasmonate pathway mediates salt tolerance in grapevines

Area of Science:

• Plant Biology
• Molecular Biology
• Stress Physiology

Background:

• Salt stress is a significant agricultural challenge, particularly for crops like grapevine.
• Jasmonate signaling pathways are crucial for both biotic and abiotic stress responses in plants.
• Understanding stress signal discrimination is key to improving crop resilience.

Purpose of the Study:

• To investigate the role of jasmonate signaling in grapevine's response to salt stress.
• To compare salt tolerance mechanisms in different grapevine cell lines.
• To elucidate the cross-talk between salt stress and biotic defense signaling pathways.

Main Methods:

• Analysis of jasmonate ZIM/tify-domain (JAZ/TIFY) proteins, Na(+)/H(+) EXCHANGER (NHX1), STILBENE SYNTHASE (StSy), and RESVERATROL SYNTHASE (RS) in grapevine cell lines.
• Monitoring apoplastic alkalinization to assess calcium channel activity.
• Evaluating the effects of exogenous jasmonate and signaling inhibitors (phenidone, aspirin).

Main Results:

• Salt stress shares signaling events with biotic defense, including calcium influx and transient JAZ/TIFY induction.
• Exogenous jasmonate improved growth in salt-sensitive cells; its signaling suppression blocked JAZ/TIFY induction.
• Biotic defense gene (RS, StSy) induction was delayed under salt stress, while NHX1 was induced in tolerant cells.

Conclusions:

• Salt stress signaling may act as a default pathway modulated by biotic factors downstream of jasmonate signaling.
• Jasmonate signaling plays a protective role against salt stress in grapevine.
• Distinct molecular responses differentiate salt-tolerant and salt-sensitive grapevine cell lines.