Omics Integration Reveals Hormonal Adjustments in Irrigated and Nonirrigated Rice Varieties Upon Mythimna separata...

Area of Science:

• Agricultural Science
• Plant Biology
• Entomology

Background:

• Freshwater scarcity challenges irrigated rice (Oryza sativa L.) cultivation.
• Nonirrigated rice farming offers a water-saving alternative.
• Both rice types face insect pest pressures, necessitating comparative studies on herbivory responses.

Purpose of the Study:

• To compare the molecular and metabolic responses of irrigated and nonirrigated rice to oriental armyworm (Mythimna separata) herbivory.
• To identify key plant hormone pathways involved in rice defense against insect feeding.
• To inform strategies for enhancing pest resistance in nonirrigated rice systems.

Main Methods:

• Integrated transcriptomic and metabolomic analyses were performed on rice plants subjected to 48 hours of continuous oriental armyworm herbivory.
• Differential gene expression (DEGs) and metabolite accumulation (DAMs) were quantified.
• Analysis focused on enrichment in plant hormone signal transduction pathways.

Main Results:

• Insect herbivory induced greater changes in DEGs and DAMs in irrigated rice than in nonirrigated rice.
• Abscisic acid, salicylic acid, and auxin pathways showed heightened responsiveness to herbivory in irrigated rice.
• Jasmonic acid pathways were activated in both cultivation types under stress.

Conclusions:

• Nonirrigated rice exhibits a reduced molecular and metabolic defense response to oriental armyworm feeding compared to irrigated rice.
• Findings highlight differential plant defense strategies based on water management.
• Results support research into nonirrigated rice resistance and potential pest management applications.