Navigation Links
Can cacti 'escape' underground in high temperatures?
Date:11/24/2010

In the scorching summer heat of the Chihuahuan Desert in southwest Texas, air temperatures can hover around 97F (36C) while at the surface of the soil temperatures can exceed 158F (70C). Encountering these extreme temperatures, plants must utilize creative methods to not only survive but thrive under these difficult and potentially lethal conditions.

This new work by Dr. Gretchen North and colleagues, published in the December issue of American Journal of Botany (http://www.amjbot.org/cgi/reprint/ajb.1000286v1), sheds light on how one desert resident, the cactus Ariocarpus fissuratus, copes with the effects of high temperatures.

"One crucial point is that small desert plants such as the 'living rock' cactus occupy one of the hottest habitats on earth, the surface of desert soils" stated North.

Ariocarpus fissuratus earned its nickname "living rock" because it blends into the rocky surroundings with its small stature that is level with the soil's surface. The researchers hypothesized that the cactus could "escape" high temperatures by moving more of itself below the soil surface where it is cooler.

Measuring changes in plant depth and root anatomy, North and co-workers determined that the cactus moves deeper into the soil by contracting its roots. But does root contraction play a protective role by modulating temperatures?

To find out, the researchers mimicked summer desert conditions by growing plants on a rooftop in Los Angeles, where air temperature was above 99F for several days. All the cacti were grown in sandy soil, but half had rocks covering the surface of the soil, similar to their native habitats. For plants grown in rocky soils, the internal temperature of the stem was about 39F lower than those grown in sandy soils alone. While this may seem like a small decrease, it had a significant effect on the health of the plants.

Unlike the cacti grown in sandy soil which all died, those grown in rocky soil survived the intense heat. Root contraction aided in lowering the internal stem temperature, but only when combined with the cooling effects of the rocky surface. The opposite was true in sandy soil where cacti planted higher above the surface had slightly lower stem temperatures than those planted close to the surface.

"Even in rocky soil, experimental plants attained nearly lethal temperatures during a summer heat wave in Los Angeles" said North. "Thus, root contraction and rocky microhabitats may not provide enough protection should desert temperatures get much higher due to global warming.


'/>"/>

Contact: Richard Hund
rhund@botany.org
314-577-9557
American Journal of Botany
Source:Eurekalert  

Related biology news :

1. Breast cancer cells recycle to escape death by hormonal therapy
2. Ancient geologic escape hatches mistaken for tube worms
3. Tree lizard’s quick release escape system makes jumpers turn somersaults
4. HIV adapts to escape immune response
5. Coral cant escape the heat
6. Escaped proteins add to hearing loss in elderly, UF researchers find
7. Cancer: Trapping the escape artist
8. If GMO genes escape, how will the hybrids do?
9. Danger lurks underground for oak seedlings
10. Researchers go underground to reveal 850 new species
11. NSF authorizes $29 million for preliminary design of worlds deepest underground laboratory
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Can cacti 'escape' underground in high temperatures?
(Date:4/13/2017)... , April 13, 2017 UBM,s Advanced ... will feature emerging and evolving technology through ... Innovation Summits will run alongside the expo portion of ... sessions, panels and demonstrations focused on trending topics within ... advanced design and manufacturing event will take place June ...
(Date:4/11/2017)... NXT-ID, Inc. (NASDAQ:   NXTD ) ("NXT-ID" or ... independent Directors Mr. Robin D. Richards and Mr. ... the company,s corporate governance and expertise. ... Gino Pereira , Chief Executive Officer said," ... and benefiting from their considerable expertise as we move forward ...
(Date:4/4/2017)... --  EyeLock LLC , a leader of iris-based identity ... and Trademark Office (USPTO) has issued U.S. Patent No. ... iris image with a face image acquired in sequence ... th issued patent. "The issuance ... multi-modal biometric capabilities that have recently come to market ...
Breaking Biology News(10 mins):
(Date:10/12/2017)... ... October 12, 2017 , ... DuPont Pioneer ... that they have entered into a multiyear collaboration to identify and characterize novel ... additional tools for gene editing across all applications. , Under the terms of ...
(Date:10/12/2017)... ... 12, 2017 , ... BioMedGPS announces expanded coverage of SmartTRAK ... module, US Hemostats & Sealants. , SmartTRAK’s US Market for Hemostats and Sealants ... sealants and biologic sealants used in surgical applications. BioMedGPS estimates the market will ...
(Date:10/12/2017)... Diego, CA (PRWEB) , ... ... ... (https://www.onramp.bio/ ) has launched Rosalind™, the first-ever genomics analysis platform specifically ... all bioinformatics complexity. Named in honor of pioneering researcher Rosalind Franklin, who ...
(Date:10/11/2017)... ... October 11, 2017 , ... The ... endogenous context, enabling overexpression experiments and avoiding the use of exogenous expression plasmids. ... is transformative for performing systematic gain-of-function studies. , This complement to loss-of-function ...
Breaking Biology Technology: