Featured Research

from universities, journals, and other organizations

Carbon Dioxide Increase In Atmosphere Augments Tolerance Of Barley To Salinity

Date:
July 10, 2008
Source:
Basque Research
Summary:
In future, climate change will bring an increase in salty surfaces on the Earth and in the concentration of carbon dioxide in the atmosphere. However, this higher carbon dioxide has some positive effects on the physiology of barley plants and increases its tolerance to salinity.

Dr Usue Pérez-López.
Credit: Image courtesy of Basque Research

In future, climate change will bring an increase in salty surfaces on the Earth and in the concentration of CO2 in the atmosphere. However, this higher CO2 has some positive effects on the physiology of barley plants and increases its tolerance to salinity.

This is the conclusion of the PhD thesis of Ms Usue Pérez-López, defended at the University of the Basque Country (UPV/EHU).

Barley is one of the most important crops in the world. In fact 56 million hectares are under barley crops, making it the fourth most grown cereal worldwide. It is widespread over all the Continents, given that it adapts very well in different habitats. As with other plants, the correct development of barley depends on a suitable balance between the availability of water, nutrients and CO2. Nevertheless, it is predicted that there will be an increase in salinity in the soil in future, causing various imbalances which will result in a reduction in the growth of barley.

According to a number of authors, an increase in the CO2 level in the atmosphere may mitigate this growth decrease of the plants caused by high concentration of salts. However, research to date differs as regards results, and it is not known if the increased levels of CO2 can mitigate the negative effects of salinity on barley. This question was addressed by UPV/EHU teacher, Usue Pérez-López, in her PhD, presented at the University’s Faculty of Science and Technology: Physiological responses of barley to the interaction of salinity and increased CO2. Prospects with climate change. Ms Pérez-López, a graduate in Biological Sciences with an Extraordinary Degree Award, carried out her work under the direction of doctors Alberto Muñoz-Rueda and Amaia Mena-Petite, from the Department of Plant Biology and Ecology. Dr. Pérez-López developed part of her research at the Department of Chemistry and Agricultural Biotechnology of the University of Pisa (Italy).

Greater rates of salinity and CO2

According to data supplied by the Food and Agriculture Organization of the United Nations (FAO), some 20% of irrigated arable surface area is subject to some level or other of salinisation, thus being hostile terrain for agriculture. Moreover, it is predicted that, in the near future, salinity will increase due to factors such as the expansion of irrigated zones, inefficient irrigation systems, the use of poor quality water and the increase in soil water loss due to greater evaporation as a consequence of high temperatures.

As a result of this increase in salinity the hydric state of barley plants will deteriorate and imbalances in their nutrition will occur due to excess sodium and chlorine (components of salt) and due to lack of potassium, calcium and nitrogen. In essence, the plant will produce less carbohydrates and proteins, which means a reduction in its growth.

The Intergovernmental Panel on Climate Change (IPCC) predicts that the CO2 concentration in the atmosphere at the end of the XXI century will double current levels. An increase contributed to by human activity through the combustion of fossil fuels and the destruction of forests. However, Dr. Pérez-López believes that barley could benefit from this increase, at least as regards mitigating the negative consequences of high salinity. Her research was based on the hypothesis that the greater the concentration of CO2, the higher the rate of photosynthesis, the hydric state of the plant is enhanced due to its lower transpiration (losing less water) and absorbs less toxic ions and is better protected against oxidation.

Dr. Pérez-López selected two varieties of barley (Hordeum vulgare cv Alpha and Hordeum vulgare cv Iranis) and studied their development, their nutritional and hydric states, their antioxidant system and carbon and nitrogen metabolisms, under high salinity and CO2 conditions, both separately and together.

Positive effects of CO2

One of the goals of Dr. Pérez-López’s thesis was to see if the increased CO2 levels would enable less chlorine and sodium to be accumulated in the tissues of the barley plant. After undertaking a study of the various plant organs, she concluded that CO2 does not mitigate the accumulation of sodium in the tissues, despite the plant showing greater growth and less transpiration.

This lower transpiration, cause by the presence of high concentrations of CO2, does attenuate the loss of water through the plant leaves, due to the fact that the stomas are kept closed and the plant tissues are dehydrated to a lesser degree. Moreover, Dr. Pérez-López observed that plants growing under these conditions show greater root development, which augments the surface for water absorption. As a consequence, deducing from Ms Pérez-López’s thesis, high levels of CO2 considerably enhances the hydric state of barley.

Dr. Pérez-López also asked herself if higher concentrations of CO2 in the atmosphere mitigate the reduction in growth caused by salinity. According to her PhD thesis, high concentrations of CO2 have a positive influence on the photosynthesis of the plant because, despite the fact that the plant keeps its stomas shut, the diffusion of CO2 between the exterior and the interior of the leaf is greater.

Finally, Dr. Pérez-López determined the oxidative stress level of the barley (the oxidation suffered by a plant due to high salinity), studied its antioxidant capacity, that is its defence mechanisms. Her conclusion was that high concentrations of CO2 alleviate this stress.

In short, Dr. Pérez-López’s research concludes that the increase in CO2 enables greater growth of barley plants subject to saline conditions, thanks to the improvement in their hydric state and turgescence, but, above all, to the increase in photosynthesis.


Story Source:

The above story is based on materials provided by Basque Research. Note: Materials may be edited for content and length.


Cite This Page:

Basque Research. "Carbon Dioxide Increase In Atmosphere Augments Tolerance Of Barley To Salinity." ScienceDaily. ScienceDaily, 10 July 2008. <www.sciencedaily.com/releases/2008/07/080707100152.htm>.
Basque Research. (2008, July 10). Carbon Dioxide Increase In Atmosphere Augments Tolerance Of Barley To Salinity. ScienceDaily. Retrieved August 23, 2014 from www.sciencedaily.com/releases/2008/07/080707100152.htm
Basque Research. "Carbon Dioxide Increase In Atmosphere Augments Tolerance Of Barley To Salinity." ScienceDaily. www.sciencedaily.com/releases/2008/07/080707100152.htm (accessed August 23, 2014).

Share This




More Plants & Animals News

Saturday, August 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Endangered Red Wolves Face Uncertain Future

Endangered Red Wolves Face Uncertain Future

AP (Aug. 22, 2014) — A federal judge temporarily banned coyote hunting to save endangered red wolves, but local hunters say that the wolf preservation program does more harm than good. Meanwhile federal officials are reviewing its wolf program in North Carolina. (Aug. 22) Video provided by AP
Powered by NewsLook.com
Farm Resurgence Grows With Younger Crowd

Farm Resurgence Grows With Younger Crowd

AP (Aug. 22, 2014) — New England farms are seeing a surge in younger farm hands as the 'buy local' food movement grows across the country. (Aug. 22) Video provided by AP
Powered by NewsLook.com
Drug Used To Treat 'Ebola's Cousin' Shows Promise

Drug Used To Treat 'Ebola's Cousin' Shows Promise

Newsy (Aug. 21, 2014) — An experimental drug used to treat Marburg virus in rhesus monkeys could give new insight into a similar treatment for Ebola. Video provided by Newsy
Powered by NewsLook.com
Terrifying City-Dwelling Spiders Are Bigger And More Fertile

Terrifying City-Dwelling Spiders Are Bigger And More Fertile

Newsy (Aug. 21, 2014) — According to a new study, spiders that live in cities are bigger, fatter and multiply faster. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins