Parasitic plants steal genes to be remodeled For outstrip parasites

Parasitic plants can use genetic material stolen from host plants to more effectively siphon off the host's nutrients, research shows. According to a new study the parasitic plant shudder has hijacked a large amount of genetic material from its hosts, in addition of including over 100 functional genes, through a process called horizontal gene transfer.
These stolen genes contribute to dodder's ability to latch onto and steal nutrients from the host and even to send genetic weapons back into the host. The new study appears July 22, 2019, in the journal Nature Plants.
"Horizontal gene transfer, the movement of genetic material from one organism into the genome of another species, is very common in microbes and is a major way that bacteria can acquire antibiotic resistance," said Claude dePamphilis, professor of biology at Penn State and senior author of the study. "We don't see many examples of horizontal gene transfer in complex organisms like plants, and when we do see it, the transferred genetic material isn't generally used. In this study, we present the most dramatic case known of functional horizontal gene transfer ever found in complex organisms."
Dodder is well known for its parasitic tendencies, though research has also suggested it 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."
Eighteen of the 108 genes appear in all dodder species, suggesting that these genes were originally stolen by the ancestral form of dodder and are maintained in modern species.
"This is the first time any study has seen signify that horizontal gene transfers occurred early in the evolution of a parasitic group," said dePamphilis. "In this case, 18 of these genes were present in the common ancestor of all the living dodder species, which may have contributed to successful spread of these parasites."
The heredity devote 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.
"But natural selection is helping maintain the useful genes and filter out the less useful segments."
The scientists are now inspecting how genetic material is being shipped from host to parasite. They would also like to explore whether this transmission is a one-way street, or if the host can obtain genetic material from its parasite.

By – Tripti varun
Content - https://www.sciencedaily.com/releases/2019/07/190722182130.htm