Comparative transcriptomic analysis reveals potential mechanisms for high tolerance to submergence in arbor willows

Area of Science:

• Plant Biology
• Genomics
• Stress Physiology

Background:

• Submergence poses a significant threat to plant growth by limiting oxygen availability.
• Understanding submergence tolerance mechanisms in Salix is crucial for breeding improved varieties.

Purpose of the Study:

• To identify key regulatory networks and genetic factors contributing to submergence tolerance in Salix.
• To compare transcriptomic differences between submergence-tolerant and -sensitive Salix varieties.

Main Methods:

• Screening of Salix germplasm for submergence tolerance.
• RNA sequencing (RNA-seq) to compare transcriptomes of tolerant ('Suliu 795') and sensitive ('Yanliu No. 1') varieties under submergence.
• Gene ontology annotation, pathway enrichment analysis, principal component analysis, and qRT-PCR for data validation.

Main Results:

• Identified 22,790 differentially expressed genes.
• Observed significant differences in transcriptional factors, hormone signaling, carbohydrate metabolism, and anaerobic respiration pathways.
• Confirmed 'Suliu 795' exhibits higher tolerance due to early low oxygen stress response, maintained energy homeostasis, and balanced phytohormone regulation (GA, SA, ethylene).

Conclusions:

• Salix submergence tolerance is a complex trait regulated by coordinated responses.
• 'Suliu 795' employs a multi-faceted strategy involving proactive stress sensing, energy management, and hormonal fine-tuning for survival.
• Findings provide insights for molecular-assisted breeding of submergence-tolerant Salix.