Final answer:
The CaMV promoter on an engineered Ti plasmid ensures significant mRNA production by promoting strong transcriptional activity of the introduced gene in plant cells.
Step-by-step explanation:
The feature on an engineered Ti plasmid that ensures the production of a significant amount of mRNA from an introduced gene is the CaMV promoter. This promoter is derived from the cauliflower mosaic virus (CaMV) and is known to be a powerful promoter in plant cells, which drives high levels of transcription and thereby increases mRNA production.
Explained in detail, promoters are essential for the initiation of transcription, serving as binding sites for RNA polymerase and other transcription factors. The CaMV promoter is highly active in plant cells, making it ideal for the production of introduced genes within plant genomes. When a gene of interest is inserted downstream of the CaMV promoter in the Ti plasmid, the resulting transgenic plants can express the gene at high levels due to the promoter's strong transcriptional activity. This is especially important in genetic engineering, where the goal is robust expression of the introduced gene. Other features such as nuclear localization signals, targeting sequences, and antibiotic resistance genes, while important for other functions in genetic engineering, do not directly increase mRNA production from the introduced gene.