Horizontal gene transfer: involving a complex plant (Introduction)

by David Turell , Tuesday, July 23, 2019, 05:23 (1950 days ago) @ David Turell

Usually not seen at this level of complexity:

https://cosmosmagazine.com/biology/parasitic-plants-steal-genes-to-become-better-parasi...

“;In this study, we present the most dramatic case known of functional horizontal gene transfer ever found in complex organisms."

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"plays a positive role in plant-plant communication

"Like other parasites it cannot live on its own; rather, it uses structures called haustoria to tap into a host plant's supply of water and nutrients. It wraps itself around its host plant, growing into its vascular tissue, and often feeds on multiple plants at one time.

"'Parasitic plants live very intimately in connection with their host, extracting nutrients," says dePamphilis. "But they also get genetic material in the process, and sometimes they incorporate that material into their genome.

“'Previous studies focused on single transferred genes. Here, we used genome-scale datasets about gene expression to determine whether the large amount of genetic material coming over through horizontal gene transfer is actually being used."

"The research team identified 108 genes that have been added to dodder's genome by horizontal gene transfer and now seem to be functional in the parasite. Eighteen of these appear in all dodder species, suggesting, the researchers say, that these genes were originally stolen by the ancestral form of dodder and are maintained in modern species.

"The genes contribute to haustoria structure, defence responses, and amino acid metabolism.

"One even produces small segments of RNA – known as micro RNA – that are sent back into the host plant, acting as weapons that may play a role in silencing host defence genes.

"The team also identified 42 regions in the dodder genome that appear to result from horizontal gene transfer, but do not have any functional genes.

"'Because such a huge quantity of genetic material has come over through horizontal gene transfer, we suspect that the parasitic plants cannot filter what is coming in," says dePamphilis"

Comment: This shows that horizontal gene transfer is not limited to just simple organisms.