Somatic Embryogenesis-Based Tetraploid Induction Enhances Biomass and Freezing Tolerance in Liriodendron Hybrid
Mingyue Xu1, Jiajie Feng1, Han Wu1
1State Key Laboratory of Tree Genetics and Breeding, College of Life Sciences, Nanjing Forestry University, Nanjing, China.
Physiologia Plantarum
|July 5, 2026
Summary
Artificial chromosome doubling in Liriodendron hybrids creates tetraploids with enhanced freezing tolerance. These polyploids exhibit improved growth and distinct defense strategies involving hormone signaling and secondary metabolism.
Area of Science:
- Plant Biology
- Genetics
- Evolutionary Biology
Background:
- Polyploidization is a significant driver of plant evolution and adaptation.
- Understanding polyploid effects on woody plants is crucial for trait improvement.
Purpose of the Study:
- Investigate the impact of artificial chromosome doubling on growth and freezing tolerance in a Liriodendron hybrid.
- Elucidate the molecular mechanisms underlying polyploid-enhanced stress adaptation.
Main Methods:
- Efficient tetraploid induction using oryzalin during somatic embryogenesis.
- Comparative analysis of growth, leaf morphology, and stomatal characteristics between diploids and tetraploids.
- Transcriptome sequencing and physiological measurements under freezing stress.
Main Results:
- Tetraploids showed compact growth, larger leaves, and enhanced freezing tolerance compared to diploids.
- Transcriptome analysis revealed differential regulation of plant hormone signaling (JA, SA, auxin), MAPK signaling, and Ca2+-mediated pathways.
- Tetraploids upregulated lignin biosynthesis genes, while diploids favored flavonoid biosynthesis for stress response.
Conclusions:
- Polyploidization in Liriodendron hybrids enhances freezing tolerance through coordinated regulation of hormone signaling and secondary metabolism.
- Tetraploids and diploids employ distinct strategies for freezing adaptation.
- This study provides an efficient tetraploid induction system and insights into polyploid adaptation in woody plants.
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