Comparative analysis of 35S and lectin promoters in transgenic soybean tissue using an automated image acquisition system and image analysis

Expression of the green fluorescent protein (gfp) gene, under regulatory control of either the constitutive 35S promoter or the developmentally-regulated lectin promoter was monitored and quantified using a newly-developed automated tracking system. The automated system consisted of a computer-controlled two-dimensional robotics table and a programmable image acquisition system, which was used to semi-continuously monitor gfp gene expression during development of transgenic soybean [Glycine max (L.) Merrill] somatic embryos. Quantitative analysis of GFP expression showed that, during somatic embryo proliferation and early development, expression of lectin-GFP was not detected. During late embryo development, expression of lectin-GFP gradually increased until the levels were similar to those of 35S-GFP. The use of an automated image collection system and image analysis facilitated the frequent monitoring and quantification of gfp gene expression on a large number of samples over an extended period of time.