A Modified Method for Transient Transformation via Pollen Magnetofection in Lilium Germplasm

Area of Science:

• Plant Biotechnology
• Molecular Biology
• Ornamental Horticulture

Background:

• Lilium (lily) is a valuable ornamental plant with limited genetic transformation efficiency using traditional methods.
• Developing efficient genetic transformation systems is crucial for advancing lily breeding and research.

Purpose of the Study:

• To establish and optimize a novel transient transformation method for lilies using pollen magnetofection.
• To assess pollen viability, exogenous gene expression, and transformation efficiency across different lily germplasm.

Main Methods:

• Optimized pollen germination medium for Lilium regale.
• Utilized nanomagnetic beads for DNA plasmid delivery via magnetofection.
• Assessed gene expression using Green Fluorescent Protein (GFP) and Beta-glucuronidase (GUS) assays.
• Evaluated transformation efficiency in various lily species and cultivars.

Main Results:

• Optimized conditions achieved 85.73% pollen germination and 88.32% transformation efficiency with magnetofection.
• Transformed pollen showed high GFP expression (69.66%), and resulting transgenic seedlings exhibited strong GUS activity (56.34%).
• Transformation efficiency varied among lily germplasm, with 'Sweet Surrender' and L. leucanthum showing high rates, while L. davidii var. willmottiae was recalcitrant.
• Pollen morphology, specifically equatorial diameter and its ratio to polar axis, correlated with transformation success.

Conclusions:

• Pollen magnetofection is a viable and efficient method for transient genetic transformation in certain lily species and cultivars.
• The study highlights the potential for pollen magnetofection in lily genetic improvement.
• Species and cultivar-specific responses indicate the need for further optimization for broader application in Lilium.