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Plants' secret weapons: What are ROS-scavenging enzymes and how do they resist drought?
As the crisis of global climate change becomes increasingly apparent, drought has become a major challenge for plant growth. In order to survive in arid environments, many plants have developed a series of self-protection mechanisms. Among them, reactive oxygen species (ROS) scavenging enzymes play a crucial role.
Drought tolerance is the ability of a plant to maintain biomass production during dry spells or water shortage conditions.
When facing drought stress, plants can carry out long-term and short-term physiological responses to maintain life activities. The short-term response involves the closure of stomata in leaves, which helps reduce water loss, while the long-term response involves the reorganization of the root system to increase water uptake capacity. At this time, the role of ROS scavenging enzymes gradually emerges. They protect plant cells by removing excess oxygen free radicals and reducing oxidative stress.
Function of ROS scavenging enzymes
Reactive oxygen species are naturally occurring molecules that act as a double-edged sword during plant growth and development. Although they play an active role in signaling and immune responses, excessive ROS can cause cellular damage.
ROS scavenging enzymes such as superoxide dismutase (SOD) and catalase (CAT) are the main weapons for plants to resist oxidative stress and can effectively reduce the content of free radicals.
These enzymes are rapidly activated when plants are experiencing drought stress in response to increased oxidative stress due to water deficiency. Through this mechanism, plants can not only slow down cell damage but also maintain normal growth and reproduction.
Plant adaptability
During the process of evolution, plants have developed a series of adaptive mechanisms to cope with different degrees of drought challenges. These adaptabilities can be divided into four categories:
- Drought escapees: Annual plants that complete their life cycle only during wet periods.
- Drought Avoiding Plants: Perennial plants that restrict growth to wet periods.
- Drought tolerant plants: Evergreen shrubs with special morphological and physiological adaptations that allow them to maintain growth under extreme drought conditions.
- Drought resistant plants: Succulents that store water in their stems or leaves.
These plants not only show adaptations in their structure, but also make adjustments in their internal biochemical processes, so exploiting these mechanisms to breed crops that are more tolerant of drought has become an important research topic.
The role of genes
Different transcription factors (TFs) are responsible for regulating the expression of genes related to drought tolerance, such as dehydration response element binding protein (DREB) and ABA response element binding factor (AREB). These transcription factors help plants adapt to drought by regulating water distribution, promoting root growth, etc.
In the study of Arabidopsis thaliana, it was found that overexpression of DREB gene can effectively enhance the plant's tolerance to drought and high-salt environment.
These genetic improvements enable agricultural researchers to create crop varieties that are more resistant to drought through genetic engineering technology, thereby enhancing food security.
Application in agriculture
As the frequency of drought events increases, damaged crops lead to reduced food production. Therefore, developing drought-resistant genetically modified crops has become an important task in global agriculture. This not only improves the efficiency of water resource utilization, but also ensures farmers' income.
The need for international cooperation
Countries are collaborating with each other in research to improve crop drought resistance. For example, international organizations such as CGIAR are promoting projects to introduce the DREB1 gene into crops such as rice and wheat to test the effect of drought resistance. This series of research and collaboration aims to develop crop varieties that are adapted to future extreme climates.
Let's think: As global climate change intensifies, how will plants evolve in the future to adapt to the changing environment?
