Low Salicylic Acid Level Improves Pollen Development Under Long-Term Mild Heat Conditions in Tomato

Area of Science:

• Plant science
• Agricultural science
• Climate change biology

Background:

• High temperatures negatively impact pollen development, threatening crop yields and food security.
• Salicylic acid (SA) is a hormone involved in plant stress responses, but its role in pollen thermotolerance is unclear.

Purpose of the Study:

• To investigate the effect of salicylic acid (SA) on pollen thermotolerance under long-term mild heat (LTMH).
• To explore the underlying molecular mechanisms, including jasmonic acid (JA) signaling, involved in pollen thermotolerance.

Main Methods:

• Assessed pollen viability in a low-SA tomato mutant (35S:nahG) exposed to LTMH.
• Conducted transcriptome, carbohydrate, and hormone analyses on the mutant line.
• Examined the relationship between SA, JA, and pollen thermotolerance.

Main Results:

• Reduced SA levels in the 35S:nahG tomato line significantly increased pollen viability under LTMH.
• Low expression of JAZ genes in the low-SA line suggests enhanced JA signaling.
• Low-JA genotypes showed hypersensitivity to LTMH, supporting the role of JA.

Conclusions:

• Lowering SA levels enhances pollen thermotolerance in tomato, potentially through an augmented jasmonic acid (JA) signaling pathway.
• These findings offer a potential strategy for developing climate-resilient crops.
• Understanding SA and JA interactions is crucial for improving crop adaptation to heat stress.