UT SCIENTISTS MAP A GENE THAT INCREASES STRESS TOLERANCE IN PLANTS
29.02.2008
Triin Vahisalu, Heino Moldau and Hannes Kollist, scientists at UT Institute of Technology, have localised a gene that regulates the function of plant stomata, i.e. microscopic pores on the leaf surface. The discovered gene affects significantly the course of plant defence reactions when the plant comes under stress, caused by water scarcity and increased concentrations of pollutants, e.g. the human-produced ozone in troposphere.
Hannes Kollist, Head of UT Plant Biology Laboratory and a member of the team who made the discovery, says that the discovered gene encodes a protein that is responsible for stomatal regulations. “Through the stomata, carbon dioxide, which is the primary nutrient of plants, enters the plant and oxygen, the ultimate prerequisite for all animal life, is released. Inevitably, however, through the open stomata the plant also loses much water. Thus, the stomata have a central role in the regulation of gas exchange, so that with a minimal loss of water the influx of carbon dioxide would still be sufficient. This is especially important when the availability of water is limited. Therefore, understanding the mechanisms of stomatal functioning is of significant importance to plant breeding and agriculture. The discovery may, for example, lead to breeding of agricultural plants that are more tolerant to drought,” Kollist explained.
There are several ion channels in the membrane of the guard cells surrounding the stomatal pores, which regulate the opening and closing of the guard cells. For example, stomata will open when stimulated by light. The closing process is triggered by drought or some other stress factor, e.g. ozone. The guard cells surrounding the stomata are some of the best studied cells. It has been known for years that an anion channel plays a central role in triggering the closing of stomata, yet the gene encoding that channel eluded the researchers up to today.
The long sought-after gene was discovered by comparing ozone-sensitive mutants of Arabidopsis thaliana (thale cress, it can also be found in Estonia). The gene was localised and its function finally described as a result of cooperation between the scientists from the University of Tartu, University of Helsinki and University of California, San Diego.
Given the human-caused climate change, understanding the molecular mechanisms of plant stomata is most important. Areas suffering from drought expand and the global human population grows. These factors force us to expand agriculture into drier and drier areas. Understanding the mechanisms of stomatal functioning is crucial for breeding agricultural plants that can endure the arid or semi-arid climate.
Increasing concentrations of ozone and carbon dioxide in the atmosphere, brought about by the climate change, pose a challenge to plants. For example, to stop the ozone from entering the leaf, the stomatal closing mechanism is triggered, which will reduce the damage caused by the ozone, yet at the same time limits the growth of the plant, since carbon dioxide, the principal nutrient of the plant, cannot enter it anymore. The discovery made by scientists is one step closer to the possibility of plants that can thrive in arid and polluted regions.
The article is available online at the website of the scientific journal Nature:
http://www.nature.com/nature/journal/v452/n7186/full/nature06608.html
Additional information: Hannes Kollist, Senior Research Fellow at UT Institute of Technology, phone +372 5647 0471
Anneli Maaring
UT Press Representative
phone +372 737 5683; +372 515 0184
anneli [dot] maaring [ät] ut [dot] ee
/64160
Hannes Kollist, Head of UT Plant Biology Laboratory and a member of the team who made the discovery, says that the discovered gene encodes a protein that is responsible for stomatal regulations. “Through the stomata, carbon dioxide, which is the primary nutrient of plants, enters the plant and oxygen, the ultimate prerequisite for all animal life, is released. Inevitably, however, through the open stomata the plant also loses much water. Thus, the stomata have a central role in the regulation of gas exchange, so that with a minimal loss of water the influx of carbon dioxide would still be sufficient. This is especially important when the availability of water is limited. Therefore, understanding the mechanisms of stomatal functioning is of significant importance to plant breeding and agriculture. The discovery may, for example, lead to breeding of agricultural plants that are more tolerant to drought,” Kollist explained.
There are several ion channels in the membrane of the guard cells surrounding the stomatal pores, which regulate the opening and closing of the guard cells. For example, stomata will open when stimulated by light. The closing process is triggered by drought or some other stress factor, e.g. ozone. The guard cells surrounding the stomata are some of the best studied cells. It has been known for years that an anion channel plays a central role in triggering the closing of stomata, yet the gene encoding that channel eluded the researchers up to today.
The long sought-after gene was discovered by comparing ozone-sensitive mutants of Arabidopsis thaliana (thale cress, it can also be found in Estonia). The gene was localised and its function finally described as a result of cooperation between the scientists from the University of Tartu, University of Helsinki and University of California, San Diego.
Given the human-caused climate change, understanding the molecular mechanisms of plant stomata is most important. Areas suffering from drought expand and the global human population grows. These factors force us to expand agriculture into drier and drier areas. Understanding the mechanisms of stomatal functioning is crucial for breeding agricultural plants that can endure the arid or semi-arid climate.
Increasing concentrations of ozone and carbon dioxide in the atmosphere, brought about by the climate change, pose a challenge to plants. For example, to stop the ozone from entering the leaf, the stomatal closing mechanism is triggered, which will reduce the damage caused by the ozone, yet at the same time limits the growth of the plant, since carbon dioxide, the principal nutrient of the plant, cannot enter it anymore. The discovery made by scientists is one step closer to the possibility of plants that can thrive in arid and polluted regions.
The article is available online at the website of the scientific journal Nature:
http://www.nature.com/nature/journal/v452/n7186/full/nature06608.html
Additional information: Hannes Kollist, Senior Research Fellow at UT Institute of Technology, phone +372 5647 0471
Anneli Maaring
UT Press Representative
phone +372 737 5683; +372 515 0184
anneli [dot] maaring [ät] ut [dot] ee
/64160