Dodder Parasite

Plant parasite evolved by gene loss, according to reports in Eurekalert 11 July 2018 and Nature Communications 11 July 2018 doi: 10.1038/s41467-018-04721-8.

Scientists in China have studied the genome and pattern of gene expression in a parasitic plant named Cuscuta australis, otherwise known as Australian dodder or southern dodder, to find out how parasitic plants evolved. This plant does not have leaves or proper roots and does not carry out photosynthesis.  They also compared the C. australis genome with the genomes of similar but non-parasitic plants from the same family, the Convolvulaceae.

The research team found about 11.7% of genes commonly found in photosynthetic plants do not exist in the dodder genome.  The missing genes included genes important for photosynthesis, various root and leaf functions, resistance to environmental stresses, and control of flowering time.  The scientists also studied the gene expression involved in the formation of haustorium, the root-like structure that attaches the dodder to the host plant, and found “haustorium formation requires mostly genes normally involved in root development”.

The researchers claim “the ancestor of Cuscuta split from the common ancestor of Cuscuta and Ipomoea (morning glories) 750 million years ago” and “the Cuscuta genome then rapidly evolved and many genes were lost during evolution.” The concluded “The C. australis genome provides important resources for studying the evolution of parasitism, regressive evolution, and evo-devo in plant parasites.”


Editorial Comment:  Regressive for sure, and yes gene loss does help to explain how this plant went from being independent to becoming a parasite, but it is not evolution.  Gene loss in the opposite of evolution.  What has happened here is a degenerative process, which has forced the plant to become completely dependent on another plant to keep it alive for a while, until the parasitized plant is ‘bled dry’ and can no longer sustain itself as well as the totally dependent dodder, then they both die.  The dodder plant has not become extinct because it hasn’t lost its ability to form flowers and set seed before it dies.

These findings fit well with Genesis, which tells us that God created plants in separate kinds in a very good world, where there were no dependent parasites that destroyed other plants. However, after man sinned, God cursed the ground and many plants have degenerated since then in varied ways – from shrinking in size, to forming thorns, and some have become parasites as they lost the ability to make and process their own food.  Overall, this parasitic plant with its deficient genome is reminder that the real history of the world is from created perfection to degeneration, or to put it more plainly, from good to bad to worse.

Evidence News vol. 18 No. 9
18 July 2018
Creation Research Australia

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