A gene (high level GC content 70 % as compared to other host gene )which is native and when express it under constitutive promoter in plant, not give high expression. what may be the cause?
Well GC-content influences codon and amino acid bias as demonstrated by many studies.
The change of GC content between the regions immediately before the gene and the gene will have an impact on the expression level (probably due to functional requirements)
There are also studies that show correlations between gene expression and Gc-content.