How effective is T-DNA insertional mutagenesis in Arabidopsis?

To evaluate the effectiveness of T-DNA insertion in knocking out a gene, 1084 published Arabidopsis thaliana insertion mutants representing 755 genes in 648 publications were reviewed. Insertion in the protein-coding region of a gene generates a knockout at least 90% of the time or 25% of the time if it is before the start codon which also produces a knockdown 67% of the time. Insertion after the stop codon had no effect on transcription of the upstream gene 17% of the time compared to 8% in insertion before the start codon. T-DNA insertion can also cause deletion and translocation.