Creationism in Crisis - How the 'Resurrection Plant' Evolved Its Special Ability to Survive Dehydration

Creationism in Crisis

How the 'Resurrection Plant' Evolved Its Special Ability to Survive Dehydration

'Resurrection plant, Craterostigma plantagineum

Creationism in Crisis

How the 'Resurrection Plant' Evolved Its Special Ability to Survive Dehydration

'Resurrection plant, Craterostigma plantagineum

Creationism in Crisis

How the 'Resurrection Plant' Evolved Its Special Ability to Survive Dehydration

'Resurrection plant, Craterostigma plantagineum

Creationism in Crisis

How the 'Resurrection Plant' Evolved Its Special Ability to Survive Dehydration

'Resurrection plant, Craterostigma plantagineum

Creationism in Crisis

How the 'Resurrection Plant' Evolved Its Special Ability to Survive Dehydration

'Resurrection plant, Craterostigma plantagineum

Creationism in Crisis

How the 'Resurrection Plant' Evolved Its Special Ability to Survive Dehydration

'Resurrection plant, Craterostigma plantagineum

Many genes are involved in “resurrection” — University of Bonn

Craterostigma plantagineum, able to recover quickly from dehydration.

If they are to survive in an environment subject to prolonged periods of dry weather, plants need to be able to survive without water for long periods and then spring back to life again when the rains come.

Ho they do this was the subject of a recent study by researchers from the universities of Bonn and Düsseldorf, Germany, and Michigan, USA, and, not surprisingly to anyone who understands biology, they found that the genes giving the so-called resurrection plant, Craterostigma plantagineum, this ability evolved out of genes also present in other plants.

In doing so, they exposed the Creationist claim that no new information can arise in a species genome without magic, otherwise it violates a fundamental law of physics, the Second Law of Thermodynamics [sic], forgetting for a moment that even with magic, that Law would still be violated, assuming for the sake of argument that it has anything to do with the amount of information in a species genome. It doesn't, of course, but the frauds who feed their cult with that sort of scientific gobbledygook know they love to think they sound all sciency and knowledgeable, but, like parrots, won't understand the noises they are making.

The resurrection plant Craterostigma plantagineum - in irrigated condition (left), desiccated (center), and then "resurrected" (right).

Photo: © AG Bartels/University of Bonn

So, what the scientists at Bonn found was that C. plantagineum not only has the genes that other plants have so their seeds can be dehydrated but still germinate, but that not only do they then not switch these genes off, but they are present in multiple copies.

C. plantagineum is an octoploid species, meaning that unlike most plants and all mammals which have just two copies of each gene, C. plantagineum has eight. At some point during its evolution, C. plantagineum doubled its genome, then doubled it again.

This gives the plant the ability to rapidly makes lots of the enzymes needed to kick-start growth after dehydration.

But that's not all. The plants have multiple copies of other genes involved in the kick-start process - the “early light inducible proteins” (ELIPs); in some cases about 200 copies, in several small clusters in their genome. These are rapidly activated by light and protect the cells from oxidative stress.

As the News release from Bonn University explains:

In their study, the researchers took a close look at a species that has long been studied at the University of Bonn - the resurrection plant Craterostigma plantagineum. It bears its name quite rightly: In times of drought, one might think it is dead. But even after months of drought, a little water is enough to revive it. “At our institute, we have been studying how the plant does this for many years,” explains Prof. Dr. Dorothea Bartels from the Institute of Molecular Physiology and Biotechnology of Plants (IMBIO) at the University of Bonn. Her interests include the genes that are responsible for drought tolerance. It became increasingly clear that this ability is not the result of a single “miracle gene.” Instead, a great many genes are involved, most of which are also found in species that do not cope so well with drought. The plant has eight copies of each chromosome In the current study, Bartel's team, together with researchers from the University of Michigan (USA), analyzed the complete genome of Craterostigma plantagineum. And this is built quite complex: While most animals have two copies of each chromosome - one from the mother, one from the father - Craterostigma has eight. Such an “eightfold” genome is also called octoploid. We humans, in contrast, are diploid. “Such a multiplication of genetic information can be observed in many plants that have evolved under extreme conditions,” Bartels says. But why is that? A probable reason: If a gene is present in eight copies instead of two, it can in principle be read four times as fast. An octoploid genome can therefore enable large quantities of a required protein to be produced very quickly. This ability also appears to be important for the development of drought tolerance. In Craterostigma, some genes associated with greater tolerance to drought are even further replicated. These include the so-called ELIPs - the acronym stands for “early light inducible proteins”, as they are rapidly switched on by light and protect against oxidative stress. They occur in high copy numbers in all drought-tolerant species. “Craterostigma has close to 200-ELIP genes that are nearly identical and are located in large clusters of ten or twenty copies on different chromosomes,” Bartels explains. Drought-tolerant plants can therefore presumably draw on an extensive network of genes that they can rapidly upregulate in the event of drought. Drought-sensitive species usually have the same genes - albeit in lower copy numbers. This is also not surprising: The seeds and pollen of most plants are often still able to germinate after long periods without water. So they also have a genetic program to protect against drought. “However, this program is normally switched off at germination and cannot be reactivated afterwards,” the botanist explains. “In resurrection plants, in contrast, it remains active.” Most species “can do” drought tolerance Drought tolerance, then, is something that the vast majority of plants “can do.” The genes that confer this ability probably emerged very early in the course of evolution. However, these networks are more efficient in drought-tolerant species and, moreover, are not active only at certain stages of the life cycle. That said, not every cell in Craterostigma plantagineum has the same “drought program” either. This was shown by researchers from the University of Düsseldorf, who were also involved in the study. For instance, different drought network genes are active in roots during desiccation than in leaves. This finding is not unexpected: Leaves, for instance, need to protect themselves against the damaging effects of the sun. They are helped in this by ELIPs, for example. With sufficient moisture, the plant forms photosynthetic pigments that at least partially absorb radiation. This natural protection largely fails during drought. Roots, in contrast, do not have to worry about sunburn. The study improves understanding of why some species suffer so little from drought. In the long term, it could therefore contribute to the breeding of crops such as wheat or corn that cope better with drought. In times of climate change, these are likely to be in greater demand than ever in the future.

Copyright: © 2023 The authors.
Published by Society for Experimental Biology and John Wiley & Sons Ltd. Open access. (CC BY-NC-ND 4.0)

The open access paper is available in The Plant Journal:

SUMMARY

Resurrection plants can survive prolonged life without water (anhydrobiosis) in regions with seasonal drying. This desiccation tolerance requires the coordination of numerous cellular processes across space and time, and individual plant tissues face unique constraints related to their function. Here, we analyzed the complex, octoploid genome of the model resurrection plant Craterostigma (C. plantagineum), and surveyed spatial and temporal expression dynamics to identify genetic elements underlying desiccation tolerance. Homologous genes within the Craterostigma genome have divergent expression profiles, suggesting the subgenomes contribute differently to desiccation tolerance traits. The Craterostigma genome contains almost 200 tandemly duplicated early light-induced proteins, a hallmark trait of desiccation tolerance, with massive upregulation under water deficit. We identified a core network of desiccation-responsive genes across all tissues, but observed almost entirely unique expression dynamics in each tissue during recovery. Roots and leaves have differential responses related to light and photoprotection, autophagy and nutrient transport, reflecting their divergent functions. Our findings highlight a universal set of likely ancestral desiccation tolerance mechanisms to protect cellular macromolecules under anhydrobiosis, with secondary adaptations related to tissue function.

VanBuren, R., Wai, C.M., Giarola, V., Župunski, M., Pardo, J., Kalinowski, M., Grossmann, G. and Bartels, D. (2023), Core cellular and tissue-specific mechanisms enable desiccation tolerance in Craterostigma.
Plant J. DOI: 10.1111/tpj.16165

Copyright: © 2023 The authors.
Published by Society for Experimental Biology and John Wiley & Sons Ltd. Open access.
Reprinted under a Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0)

No crumbs of comfort for Creationists there then. We have new information arising by gene duplication; we have beneficial mutations which their cult leaders say are impossible because all mutations are allegedly detrimental, therefore 'devolutionary' [sic], and we have the scientists in no doubt that the Theory of Evolution explains what they observe, in contrast to Creationist fraud claims that the TOE is being increasingly rejected by mainstream biologists.

And we have the evidence of common descent in the fact that other plants have the same genes or their homologues.

Yet another science paper that refutes creationism without even trying, in fact.

---

Thank you for sharing!

Tweet Link