Neochrome is a hybrid of two other plant genes which code
for photoreceptor proteins that sense red and blue light. This gene is thought
to have been responsible for the evolution of ferns. Most plants sense and grow
toward blue light, but under the canopy, there is less blue and more red light.
Researchers wanted to know where this gene originated in ferns. They searched through
plant genomes and found a similar gene in hornworts.
They came up with 3 hypothesis for the involvement of neochrome in both ferns and hornworts: They could have had a common ancestor,
they might have evolved their gene independently, or neochrome could have been
moved across species by horizontal gene transfer. In order to come to a conclusion, teams of scientists looked through land plants and algae and how their light sensitive genes were related.
Because the ferns and hornworts diverged in evolution 400 million years ago, if neochrome had come from a common ancestor, it would have been passed on to other plants as well, but since no other plants seem to possess this gene that possibility was ruled out. Because neochrome is such an unique gene, it is also extremely unlikely for ferns and hornworts to have evolved the gene independently. Scientists came to the conclusion that the most probable origin of this gene in ferns was through horizontal gene transfer. Scientists are seeing more and more cases of horizontal gene transfer in plants, but they do not know how it is mediated as of yet.
This article was extremely interesting, up until now I only knew of horizontal gene transfer occurring exclusively in bacteria. It only makes me wonder how much we do not know about plants still and how we could use this recent discovery to our advantage.
http://www.sciencedaily.com/releases/2014/04/140414154444.htm Main article
http://www.decodedscience.com/hornworts-loan-genes-ferns-shady-environments/44670
http://www.sciencedaily.com/releases/2014/04/140414154444.htm Main article
http://www.decodedscience.com/hornworts-loan-genes-ferns-shady-environments/44670
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