Electroporated protoplasts express seed specific gene promoters

Area of Science:

• Plant molecular biology
• Gene expression analysis
• Protein biochemistry

Background:

• Soybean (Glycine max) 7S seed storage protein, β-conglycinin, consists of α', α, and β subunits.
• Understanding the regulatory elements of seed storage protein genes is crucial for plant biotechnology.

Purpose of the Study:

• To investigate the activity and regulation of soybean β-conglycinin promoters in heterologous systems.
• To compare the expression patterns of β-conglycinin promoters with a strong constitutive promoter (CaMV 35S) in tobacco cells.

Main Methods:

• Construction of chimeric genes using β-conglycinin subunit promoters and the β-glucuronidase reporter gene.
• Electroporation of chimeric genes into protoplasts from cultured soybean cell lines and tobacco mesophyll cells.
• Analysis of gene expression levels and patterns, including cell cycle dependency and response to chemical treatments.

Main Results:

• β-conglycinin promoters demonstrated activity in all tested protoplasts, achieving 10-60% of CaMV 35S promoter activity.
• Expression timing and cell cycle dependency in tobacco suspension culture protoplasts mirrored the 35S promoter.
• Responses to L-methionine and abscisic acid were similar across tested promoters, unlike observations in soybean cotyledons.

Conclusions:

• Soybean β-conglycinin promoters are functional in electroporated tobacco protoplasts.
• The regulatory mechanisms controlling β-conglycinin promoter expression in heterologous protoplasts are less stringent than in native soybean cotyledons.