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Desert microbes can help with fighting climate change
As people moved into the new millennium, global organizations like NASA and the United Nations started to express their concerns about climate change, and how it can affect the population of Earth in the long term. Implementation of sustainable practices in all spheres of life are becoming crucial for transitioning to a more eco-friendly way of living, thus ensuring a future on this planet. With the growth of Earth’s population, sustainable agriculture methods can not only provide necessary food reserves, but also eliminate or minimize harmful to the environment footprint. In order to develop new cultivation practices, numerous research groups have focused on studying desert plants. This sounds almost counterintuitive, since desert plants are not known for producing crops and fruits that can be consumed. However, deserts cover 33% of the total land area of Earth, and what distinguishes these plants from others is their unique adaptation abilities to a habitat with extreme temperature fluctuations, high solar radiation, and water scarcity. If scientists can understand how these plants manage to survive, perhaps, they could find a new agricultural method that will allow farmers to explore new areas and lands.
Just a quick glance, and you will notice how unusual desert plants are (see images below). Dry and hot conditions contributed to their very specific look. Leaves of desert plants are very narrow to minimize exposure to radiation. Thick layer of wax, that gives almost a glossy appearance to a plant, prevents water evaporation. Underneath the sand and layers of soil hides an extensive root system that enables plants to access water. What is also interesting about the root system is how tightly its functioning depends on microorganisms (read the article “A Deeply Rooted Connection” to learn more). Yes, desert soil is full of microbial life! Just a quick glance, and you will notice how unusual desert plants are (see images below). Dry and hot conditions contributed to their very specific look.and hot conditions contributed to their very specific look. Leaves of desert plants are very narrow to minimize exposure to radiation. Thick layer of wax, that gives almost a glossy appearance to a plant, prevents water evaporation. Underneath the sand and layers of soil hides an extensive root system that enables plants to access water. What is also interesting about the root system is how tightly its functioning depends on microorganisms (read the article “A Deeply Rooted Connection” to learn more). Yes, desert soil is full of microbial life!
Plant growth promoting bacteria (PGPB) are bacteria that stimulate growth of plants and even protect them against pathogens. These bacteria play such a vital role in a plant’s life cycle, that their presence is essential for a plant’s survival. Not surprisingly, desert plants also have them. PGPB of desert plants are usually found in rhizosheaths – soil particles that physically adhere to the root system. The two most dominant phyla are represented by Proteobacteria and Actinobacteria. Proteobacteria have the power to fix nitrogen, which is an essential element for every plant. Actinobacteria are known for growing under versatile extreme conditions, like environments with high or low pH, extreme temperatures, or abnormal levels of radiation and pressure.
To enhance the growth without using fertilizers or other compounds that can negatively affect the environment, some studies suggest a method of isolating soil particles that are rich in growth-promoting bacteria and transferring those to a new plant. A study conducted in 2008 by Aseri et al. demonstrated that PGPB can be used as biofertilizers in arid regions such as Thar Desert (India). In the field experiment that lasted 5 years, researchers have been continuously supplementing a pomegranate tree with a nitrogen-fixing bacteria Azotobacter chroococcum. This plant was initially chosen because pomegranates are usually cultivated in world regions with arid soils and hot climates, like Indian subcontinent or Mediterranean countries. Therefore, it was hypothesized that this microorganism will be able to enhance a plant’s growth by supplying pomegranate trees with essential nitrogen compounds. The results demonstrated an enhanced plant height and fruit yield, higher chlorophyll content, and better nutrient uptake. The researchers demonstrated that this technique was successful and could be used to improve agricultural practices in countries with unfavorable climates.
Throughout the years, many other studies and projects were initiated to discover the possibility of using desert microbes. One of the most widely known projects is called DARWIN21, and it mainly focuses on studying microbial life in the Arabian Peninsula deserts. It was started with the idea to explore new possibilities of increasing rates of food production in countries with hot and dry climates. Those regions heavily depend on imports and foreign aid, due to the unfavorable environment for agriculture. In order to solve this problem, researchers focused on studying desert plants and their adaptation mechanisms. This led to the establishment of the first world heritage stock center for desert microbes. Today, scientists are studying rhizosheaths microbes and how they can increase plant tolerance to stress conditions, like drought or water scarcity. Undoubtedly, projects like that will help with the implementation of sustainable agricultural methods. Who knows, maybe in a couple of years farmers will be able to grow fruits and vegetables in the Sahara desert?
Link to the original post: lsharif Wiam, Saad Maged M., Hirt Heribert, Desert Microbes for Boosting Sustainable Agriculture in Extreme Environments, Frontiers in Microbiolog, 2020
Featured image: https://www.darwin21.org
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