Scientists from the Universities of Bonn and Michigan have discovered that the extraordinary ability of certain plants to endure prolonged drought and revive after rainfall is not attributed to a single “miracle gene,” but rather to an intricate network of genes.
The research team conducted an extensive analysis of the genome of a drought-tolerant plant to unravel the secrets behind its resilience. Their joint study, published in The Plant Journal, reveals that the unique trait observed in certain plant species, where they can endure extended periods without water and rejuvenate upon experiencing even a minor rain shower, is not governed by a solitary gene. Instead, it emerges from a complex interconnection of genes, many of which can also be found in less resistant plant varieties.
The spotlight of the investigation was the resurrection plant, scientifically known as Craterostigma plantagineum, which has been extensively studied at the University of Bonn. Aptly named for its ability to seemingly come back to life during droughts, this remarkable plant requires only a small amount of water to spring back to its green state, even after appearing lifeless following months of water scarcity.
Prof. Dr. Dorothea Bartels from the Institute of Molecular Physiology and Biotechnology of Plants (IMBIO) at the University of Bonn, who has been studying the plant’s ability for many years, explains, “We have been researching the genes responsible for drought tolerance at our institute, and it became increasingly evident that this ability is not attributed to a single ‘miracle gene.’ Instead, numerous genes are involved, many of which are also present in plant species that are less adept at coping with drought.”
The researchers delved into the complete genome of Craterostigma plantagineum, and their analysis revealed that this plant possesses eight copies of each chromosome, making it an octoploid organism. In contrast, most animals, including humans, are diploid, possessing two copies of each chromosome, one from each parent.
Prof. Bartels explains the significance of this genetic duplication, stating, “Multiplication of genetic information of this scale can be observed in many plants that have evolved in extreme conditions. The reason behind this is that if a gene is present in eight copies instead of two, it can be read four times faster. An octoploid genome allows for the rapid production of large quantities of essential proteins, which seems to be crucial for developing drought tolerance.”
Within Craterostigma, certain genes associated with enhanced drought tolerance are further replicated, such as the “early light-inducible proteins” (ELIPs), which are rapidly activated by light and protect against oxidative stress. ELIPs exist in high copy numbers across all drought-tolerant species. Prof. Bartels explains, “Craterostigma contains nearly 200 identical ELIP genes that are clustered in groups of ten or twenty copies on different chromosomes. Drought-tolerant plants can thus access an extensive network of genes that can be rapidly upregulated in response to drought conditions.”
In contrast, drought-sensitive species possess the same genes, albeit in lower copy numbers. This is not surprising since the seeds and pollen of most plants can still germinate after prolonged periods without water, indicating the existence of a genetic program to withstand drought. However, in resurrection plants like Craterostigma, this program remains active instead of being deactivated after germination.
Drought tolerance appears to be a capability possessed by the majority of plant species, as the genes conferring this ability likely emerged early in evolution. However, these gene networks are more efficient in drought-tolerant species and remain active throughout various stages of the life cycle.
Furthermore, the study highlights that not every cell in Craterostigma plantagineum follows the same “drought program.” Researchers from the University of Düsseldorf, also involved in the study, found that different drought network genes are active in the roots during desiccation compared to the leaves. This observation is expected since leaves require protection against the sun’s damaging effects, aided by ELIPs, for example. With adequate moisture, the plant develops photosynthetic pigments that partially absorb radiation, providing natural protection that largely diminishes during drought. In contrast, roots are not susceptible to sunburn and, therefore, do not require the same level of protection.
The findings of this study enhance our understanding of why some species exhibit remarkable resilience to drought. In the long run, this knowledge could contribute to the development of drought-tolerant crops like wheat and corn, which will likely be in high demand amid the challenges posed by climate change.
The study involved collaboration between the University of Bonn, Michigan State University, and Heinrich Heine University Düsseldorf. Funding for the research was provided by the US National Science Foundation (NSF) and the German Research Foundation (DFG).
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Frequently Asked Questions (FAQs) about Plant Resilience
What is the main finding of the study?
The main finding of the study is that the ability of certain plants to survive prolonged drought and revive after rain is not due to a single “miracle gene,” but rather a network of interconnected genes.
Which universities conducted the research?
The research was conducted by the Universities of Bonn and Michigan.
What plant species was studied?
The plant species studied was Craterostigma plantagineum, commonly known as the resurrection plant.
How does the resurrection plant survive drought?
The resurrection plant can survive drought by having an extensive network of genes that allow it to rapidly upregulate essential proteins when faced with water scarcity.
Are these genes unique to drought-tolerant plants?
No, many of these genes can also be found in less resistant plant varieties. The ability to withstand drought is a result of the efficiency and activation of these genes in drought-tolerant species.
What is an octoploid genome?
An octoploid genome refers to a genetic makeup where an organism possesses eight copies of each chromosome. In the case of the resurrection plant, Craterostigma plantagineum, it has an octoploid genome.
How can this research benefit agriculture?
Understanding the complex genetic network responsible for drought tolerance can aid in the breeding of crops, such as wheat or corn, that can better cope with drought. This knowledge is particularly important in the context of climate change.
More about Plant Resilience
- The Plant Journal: Link to the research paper
- University of Bonn: Research news article
- Michigan State University: Research news article
- Heinrich Heine University Düsseldorf: Research news article
- US National Science Foundation (NSF): Official website
- German Research Foundation (DFG): Official website
