Navigation Links
Can cacti 'escape' underground in high temperatures?

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 (, 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
American Journal of Botany

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:
Related Image:
Can cacti 'escape' underground in high temperatures?
(Date:6/22/2016)... On Monday, the Department of Homeland Security ... solutions for the Biometric Exit Program. The Request for ... (CBP), explains that CBP intends to add biometrics to ... United States , in order to deter visa ... Logo - ...
(Date:6/9/2016)... , June 9, 2016  Perkotek an innovation leader in attendance control systems ... seamlessly log work hours, for employers to make sure the right employees are actually ... ... ... ...
(Date:6/2/2016)... 2, 2016   The Weather Company , an IBM ... an industry-first capability in which consumers will be able to ... ask questions via voice or text and receive relevant information ... Marketers have long sought an advertising solution that ... be personal, relevant and valuable; and can scale across millions ...
Breaking Biology News(10 mins):
(Date:6/24/2016)... 24, 2016 Epic Sciences unveiled a ... susceptible to PARP inhibitors by targeting homologous recombination ... The new test has already been incorporated into ... cancer types. Over 230 clinical trials ... pathways, including PARP, ATM, ATR, DNA-PK and WEE-1. ...
(Date:6/23/2016)... ... June 23, 2016 , ... ... to announce the launch of their brand, UP4™ Probiotics, into Target stores nationwide. ... years, is proud to add Target to its list of well-respected retailers. This ...
(Date:6/23/2016)... , June 23, 2016 Houston ... with the Cy-Fair Sports Association to serve as ... the agreement, Houston Methodist Willowbrook will provide sponsorship ... and connectivity with association coaches, volunteers, athletes and ... with the Cy-Fair Sports Association and to bring ...
(Date:6/23/2016)... --  EpiBiome , a precision microbiome engineering company, today ... from Silicon Valley Bank (SVB). The financing will allow ... drug development efforts, as well as purchase additional lab ... been an incredible strategic partner to us – one ... provide," said Dr. Aeron Tynes Hammack , EpiBiome,s ...
Breaking Biology Technology: