Plants rapidly adapt (not evolve) due to HGT, TEs and exosomes without Darwin


The article "Pioneer Arabidopsis thaliana spans the succession gradient revealing a diverse root-associated microbiome" by Vera Hesen et al. (2023) investigated the root-associated microbiome of Arabidopsis thaliana (A. thaliana) across a secondary succession gradient. A. thaliana is a model plant species that is often used to study epigenetics as well as plant-microbiome interactions. However, most studies of A. thaliana have focused on early successional stages, when the plant is growing in disturbed soils. This study investigated whether A. thaliana can also establish in later successional stages, when the soil is more complex and has a more diverse microbiome.

The researchers grew A. thaliana plants in soils from different successional stages, from early succession to late succession. They then sequenced the DNA of the bacteria and fungi associated with the plant roots. They found that the root-associated microbiome of A. thaliana was diverse and changed along the succession gradient. In early successional soils, the microbiome was dominated by bacteria from the genera Pseudomonas, Bacillus, and Enterobacter. In later successional soils, the microbiome was more diverse, with a greater representation of fungi.

The researchers also found that the root-associated microbiome of A. thaliana influenced the plant's growth and development. Plants grown in soils with a diverse microbiome had a higher biomass and were more resistant to stress than plants grown in soils with a less diverse microbiome.

This study provides new insights into the role of the root-associated microbiome in A. thaliana's success across a secondary succession gradient. The findings suggest that the plant's ability to establish in later successional stages is influenced by the composition of the root-associated microbiome. This knowledge could be used to improve the growth and development of A. thaliana in agricultural systems.

Here are some of the key findings of the study:

  • A. thaliana can successfully establish in soils that have experienced years of ecological development.

  • The root-associated microbiome of A. thaliana is diverse and changes along the succession gradient.

  • The root-associated microbiome influences the plant's growth and development.

  • Plants grown in soils with a diverse microbiome have a higher biomass and are more resistant to stress than plants grown in soils with a less diverse microbiome.

This study provides new insights into the role of the root-associated microbiome in A. thaliana's success across a secondary succession gradient. The findings suggest that the plant's ability to establish in later successional stages is influenced by the composition of the root-associated microbiome. This knowledge could be used to improve the growth and development of A. thaliana in agricultural systems.

The plant microbiome is a complex and dynamic ecosystem that plays a vital role in plant health and development. Recent research has shown that the microbiome can also mediate horizontal gene transfer (HGT) of transposable elements (TEs) between plants and microbes.


TEs are mobile genetic elements that can move around the genome, sometimes inserting themselves into new locations. This can have a variety of effects on the plant, including changing gene expression, disrupting development, and even causing disease.

HGT of TEs can occur between plants through a variety of mechanisms, including pollen transfer, root exudates, and even insect vectors. However, recent research has shown that the plant microbiome can also play a role in HGT of TEs.

One way that the microbiome can mediate HGT of TEs is through the production of exosomes. Exosomes are small extracellular vesicles that are released by cells. They can contain a variety of cargo, including TEs. When a plant comes into contact with a microbe that is producing exosomes containing TEs, the TEs can be taken up by the plant cell.


Once inside the plant cell, the TEs can then integrate into the plant genome. This can have a variety of effects on the plant, as mentioned above.

In addition to mediating HGT of TEs through exosomes, the plant microbiome can also influence HGT of TEs through epigenetics. Epigenetics is the study of changes in gene expression that are not caused by changes in the DNA sequence as per Darwin. These changes can be caused by environmental factors, such as the presence of certain microbes.

For example, one study found that the presence of a specific type of bacteria, Pseudomonas syringae, could induce the expression of TEs in Arabidopsis thaliana. This suggests that the microbiome can influence HGT of TEs by epigenetically altering the plant's genome.

The study of HGT of TEs via exosomes and epigenetics is a relatively new field of research. However, it is clear that the plant microbiome plays a significant role in this process. As we learn more about this process, we may be able to develop new strategies for controlling TEs and preventing the spread of plant diseases.

The transfer of genetic material between organisms (HGT) via exosomes and epigenetics occurs outside of the Neo Darwinian framework. Neo Darwinism is a theory of evolution that states that evolution is driven by natural selection acting on genetic variation. However, HGT can introduce new genetic material into an organism's genome that is not the result of NeoDarwinian mutations or recombination. This new genetic material can then be inherited by the organism's offspring, which can lead to new traits and adaptations.

For example, research has shown that plant microbiomes can transfer transposable elements (TEs) to the plant's genome. TEs are mobile pieces of DNA that can insert themselves into other genes, causing changes in gene expression. These changes can lead to new traits or adaptations in the plant without Darwin.

Epigenetics is another way that HGT can occur outside of neo darwinism. Epigenetics refers to changes in gene expression that are not caused by changes in the DNA sequence as per Darwin's mutations.


These changes can be caused by environmental factors, such as diet or stress, or by interactions with the microbiome. Epigenetic changes can be inherited by offspring.

The discovery of HGT via exosomes and epigenetics has challenged the neo darwinian view of evolution. These mechanisms suggest that evolution is not just driven by natural selection acting on genetic variation, but also by the transfer of genetic material between organisms. This has led to a new understanding of evolution, one that is more complex and dynamic than the traditional neo darwinian view.



Comments

Post a Comment

Popular posts from this blog

Beyond the Sequence: The Epigenetic "Fingers" That Play the DNA Keyboard

Image
Imagine the keyboard itself is not a standard piano keyboard, but a modular synthesizer, capable of producing an almost infinite array of sounds. The DNA sequence, then, represents the fundamental building blocks of this synthesizer, the raw materials from which all sounds are generated. Epigenetics, our "fingers," manipulates these building blocks, adjusting parameters like volume, timbre, and rhythm, transforming the raw potential of the DNA sequence into a symphony of cellular functions. We can further refine the "fingers" analogy. Consider that each finger represents a distinct epigenetic mechanism: DNA methylation, histone modifications, and non-coding RNA.  DNA methylation, for instance, might be the "index finger," capable of precisely silencing specific genes, like muting individual keys on the synthesizer. Histone modifications, the "middle finger," could represent the ability to adjust the accessibility of the DN...
Read more

Rewriting the Rules: Epigenomic Mutation Bias Challenges Randomness in Evolution

Image
This research challenges the long-held dogma that mutations occur randomly, irrespective of their consequences, by demonstrating a clear, epigenome-mediated mutation bias in Arabidopsis thaliana . The study meticulously unveils how mutation rates are not uniform across the genome but are significantly reduced in functionally constrained regions, particularly within gene bodies and essential genes. This discovery fundamentally alters our understanding of evolutionary processes, suggesting that mutation is not a purely directionless force. "Mutation bias reflects natural selection in Arabidopsis thaliana" This opening statement encapsulates the core finding: mutation rates are not random but reflect epigenetic pressures. The authors demonstrate that mutations are less frequent in crucial genomic regions, directly contradicting the prevailing theory of random mutation. This observation suggests an active mechanism that minimizes deleterious mutations in essentia...
Read more

Why are Christian philosophers running towards Darwin while biologists are "running" away?

Image
As nature reveals the strength of epigenetics and the weakness of Neo-Darwinism, biologists are “running” away from the long-standing accepted theory. In The Federalist , April 2019, Benjamin Dierker reviews “Why one-third of biologists now question Darwinism”: "Current estimates are that approximately one-third of professional academic biologists who do not believe in intelligent design find Darwin’s Theory inadequate to describe all of the complexity in biology.” Dierker continues, “The important note is that these are not ideologues or religious zealots, nor do they propose a god or biblical solution.  Rather, they find problems in the lack of explanatory power of Darwin’s theory in light of modern understanding of mutation, variation, DNA sequencing and more. These expressions of doubt do not reject naturalism or evolution per se, but the rigor of the Neo-Darwinian model for explaining the development of life.” For 40 years, scientists calculated natural se...
Read more