CO mRNA is produced approximately 12 hours after dawn , a cycle regulated by the plant 's biological clock .
In Arabidopsis thaliana , the signal is initiated by the production of messenger RNA ( mRNA ) coding a transcription factor called CONSTANS ( CO ) .
mRNA   is produced approximately 12 hours after dawn , a cycle regulated by the plant 's biological clock .
In Arabidopsis thaliana , the signal is initiated by the production of messenger RNA ( mRNA ) coding a transcription factor called CONSTANS ( CO ) .