Salicylic Acid Modulates Volatile Organic Compound Profiles During CEVd Infection in Tomato Plants

Area of Science:

• Plant Pathology
• Plant Biochemistry
• Metabolomics

Background:

• Citrus Exocortis Viroid (CEVd) is a non-coding RNA pathogen that alters plant metabolism.
• Salicylic acid (SA) is a crucial signaling molecule in plant defense against pathogens like CEVd.
• Tomato plants (Solanum lycopersicum) exhibit metabolic changes upon viroid infection.

Purpose of the Study:

• To investigate the role of salicylic acid (SA) levels in tomato plant immunity against Citrus Exocortis Viroid (CEVd).
• To explore the impact of SA on metabolic responses, specifically volatile organic compound (VOC) profiles, during CEVd infection.

Main Methods:

• Utilized transgenic tomato lines (RNAi_S5H and NahG) with manipulated SA levels to create varying degrees of viroid resistance.
• Employed gas chromatography-mass spectrometry (GC-MS) to analyze volatile organic compound (VOC) emissions.
• Correlated VOC profiles with plant resistance/susceptibility to CEVd infection.

Main Results:

• Viroid-resistant RNAi_S5H plants showed significantly enhanced monoterpenoid production upon CEVd infection.
• Viroid-susceptible NahG plants emitted a broader range of VOCs compared to resistant plants.
• Viroid-tolerant RNAi_S5H plants exhibited less variation in VOC emission.

Conclusions:

• SA levels critically influence metabolic responses and immunity in tomato plants infected with CEVd.
• Differential VOC emissions upon CEVd infection can serve as potential biomarkers for disease detection.
• Understanding VOC profiles may lead to novel strategies for CEVd disease management.