Contiguous identity between entire coding regions of transgenic and native genes rather than special regions is essential for a strong co-suppression.

The discovery of co-suppression in plants has greatly boosted the study of gene silencing mechanisms, but its triggering mechanism has remained a mystery. In this study, we explored its possible trigger mechanism by using Fatty acid desaturase 2 (FAD2) and Fatty acid elongase 1 (FAE1) strong co-suppression systems. Analysis of small RNAs in FAD2 co-suppression lines showed that siRNAs distributed throughout the coding region of FAD2 with an accumulated peak.

Quantitative Investigation of Cosuppression Reveals RDR6-Dependent and RDR6-Independent Gene Silencing Pathways.

The frequency and extent of transgene-mediated cosuppression varies substantially among plant genes. However, the underlying mechanisms leading to strong cosuppression have received little attention. In previous studies, we showed that the expression of in the seeds of results in strong RDR6-mediated cosuppression, where both endogenous and transgenic were silenced.