Visualisation of transgene expression at the single protoplast level.

Area of Science:

• Plant biotechnology
• Molecular biology
• Cell biology

Background:

• Protoplasts are vital for studying gene expression post-transformation.
• Current methods like Western blotting analyze protein expression in bulk populations, not individual cells.
• Enzymatic activity assays also measure expression in populations, lacking single-cell resolution.

Purpose of the Study:

• To introduce a novel method, protoplast printing, for detecting protein expression in individual protoplasts.
• To enable the distinction between expressing and non-expressing cells within a population.
• To provide a simpler alternative to existing population-based expression analysis techniques.

Main Methods:

• Protoplast printing involves immobilizing protoplast proteins onto a nitrocellulose filter.
• The method retains the cellular outline for spatial protein localization.
• Immunological detection using specific antibodies identifies the protein of interest within the immobilized cell structure.

Main Results:

• Protoplast printing successfully detected the expression of the BNYVV coat protein in Chenopodium quinoa protoplasts after viral RNA electroporation.
• The method also identified NPT II gene expression in tobacco protoplasts from transgenic plants and after plasmid DNA transfer.
• Distinguishing between expressing and non-expressing cells was achieved as early as 12 hours post-transgene transfer in both viral RNA infection and plasmid DNA transformation scenarios.

Conclusions:

• Protoplast printing offers a straightforward and effective way to visualize and quantify protein expression at the single-cell level.
• This technique significantly advances the study of gene expression in protoplasts, particularly in plant biotechnology and genetic engineering.
• The method's ability to differentiate expressing cells early on facilitates rapid assessment of transformation and infection efficiency.