Evolution: carnivorous plant origin (Evolution)

by David Turell , Saturday, December 02, 2023, 20:45 (355 days ago) @ David Turell

New genetic study:

https://www.sciencedaily.com/releases/2023/11/231130184214.htm

"Scientists sequenced the genome of the East Asian pitcher plant, Nepenthes gracilis, a species of carnivorous plant related to Venus flytraps, as well as sundews, beets and spinach.

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"'Our findings not only provide key insights into the adaptive landscape of the Nepenthes genome, but also broaden our understanding of how polyploidy -- having multiple sets of chromosomes -- can stimulate the evolution of new functions," says Victor Albert, PhD, Empire Innovation Professor

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"In this new study, Albert and Fukushima's teams discovered that the specialized pitcher trap of the Asian pitcher plant, or Nepenthes, may have been promoted by polyploidy. Nepenthes' lineage had already evolved carnivory, so the duplicated genomes may have simply tweaked its mode of capture.

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"Some of Nepenthes' duplicate carnivory genes may have originally evolved for defending against what eventually became their prey. The enzymes that help Nepenthes break down insects' hard exoskeletons, for example, were repurposed from those that originally shielded plants from being eaten by these animals.

"'This lineage of Nepenthes didn't evolve new genes to become carnivorous -- they grabbed collections, or toolkits, of genes that were already there," Albert says.

"One hypothesis suggests that polyploidy has a negligible effect on long-term evolution, as species with multiplicated genomes may undergo extinction at rates higher than those like humans, which have just two sets of chromosomes. Yet the study's findings add to the evidence that ancient polyploidy events can sometimes underlie evolutionary jumps still visible among plants today.

"Nepenthes is part of the just 6% of flowering plant species that are dioecious, meaning each individual plant produces either male or female flowers. In fact, Nepenthes is the only dioecious carnivorous plant.

"Albert and Fukushima's team also identified a male-specific region of the genome containing three genes potentially responsible for controlling these sex differences. One of these, called LEAFY, is a key gene expressed early in flower development that acts as a master regulator.

"'LEAFY seems to have had a duplicate form and moved into the Y chromosome region of Nepenthes, thereafter diverging in its function. This use of LEAFY is unprecedented so far in flowering plants," Albert says. "The LEAFY gene is such a central regulator across flowering plants that, when artificially added or deleted through genetic engineering, it will change a plant's flowering time.'"

Comment: we know meat-eating plants always need help with nutrition since they live on poor nitrogen and phosphate soils. Of course, my view is this is another of God's designs.