Featured Research

from universities, journals, and other organizations

Learning to live on land: How some early plants overcame an evolutionary hurdle

Date:
September 22, 2010
Source:
American Journal of Botany
Summary:
Diversity of life would be impossible if the ancestors of modern plants had stayed in the water with their green algal cousins. Moving onto dry land required major changes to adapt to this new "hostile" environment, and helped change global climate and atmospheric conditions. By absorbing carbon while making food, and releasing oxygen, early plants shaped ecosystems into a more hospitable environment. New research suggests reasons for incorporating evolutionary/paleontological information into global carbon cycling models.

This is reproductive Sphagnum peat moss, showing dark brown sporophytes that explosively discharge spores, perched on green gametophytes.
Credit: Lee Wilcox, University of Wisconsin, Madison /

The diversity of life that can be seen in environments ranging from the rainforests of the Amazon to the spring blooms of the Mohave Desert is awe-inspiring. But this diversity would not be possible if the ancestors of modern plants had just stayed in the water with their green algal cousins.

Moving onto dry land required major lifestyle changes to adapt to this new "hostile" environment, and in turn helped change global climate and atmospheric conditions to conditions we recognize today. By absorbing carbon while making food, and releasing oxygen, early plants shaped ecosystems into a more hospitable environment, paving the way for animals to make a parallel journey onto land.

New research by Dr. Linda Graham and colleagues at the University of Wisconsin, Madison focuses on this transition and adaptive changes in the uptake of carbon-based compounds, such as sugars. This work, which is published in the September issue of the American Journal of Botany, suggests a basis for incorporating evolutionary/paleontological information into global carbon cycling models.

All plants descended from a group of ancestral green algae, whose modern representatives thrive in aqueous environments. The simplest of modern land plants -- several groups of bryophytes -- are the closest living relatives to the first plants to colonize land. By comparing green algae and bryophytes, Graham and her co-researchers obtained insight into the evolutionary hurdles that plants needed to overcome to transition successfully to life on land, and how early plants' success influenced carbon cycling.

The researchers quantified and compared growth responses to exogenously (externally) supplied sugars in two green algae, Cylindrocystis brebissoni and Mougeotia sp., and one peat moss species, Sphagnum compactum. They found that sugar/carbon uptake in peat moss was not restricted to the products of photosynthesis. Rather, addition of sugars to the growth media increased biomass by almost 40-fold. This ability to utilize sugars not only from photosynthesis but also from the environment is called mixotrophy, not previously thought to play a significant role in the growth of mosses. The two green algae also responded to external sugar, though less so than the peat moss.

Peat mosses "store a large percentage of global soil carbon, thereby helping to stabilize Earth's atmospheric chemistry and climate," stated Graham.

This has far-ranging implications to global carbon cycling because previous work examining the response of mosses to carbon availability assumed that carbon dioxide was the only carbon source available to peat mosses and ancestral plants. The new results indicate that efforts to model global atmospheric and climate changes, both in the present and millions of years ago during the colonization of land, should take mixotrophic behavior of early diverging plants into account.

Graham and her co-researchers have enjoyed a cross-hemispheric partnership, from Wisconsin north to Canada and south to Chile, and look forward to comparing the biology of Northern and Southern hemisphere peat mosses. In particular, they would like to "explore in more depth the role of sugars in the establishment of ecologically important microbial symbioses, particularly nitrogen-fixing cyanobacteria living with peat mosses," explained Graham.


Story Source:

The above story is based on materials provided by American Journal of Botany. Note: Materials may be edited for content and length.


Journal Reference:

  1. L. E. Graham, E. Kim, P. Arancibia-Avila, J. M. Graham, L. W. Wilcox. Evolutionary and ecophysiological significance of sugar utilization by the peat moss Sphagnum compactum (Sphagnaceae) and the common charophycean associates Cylindrocystis brebissonii and Mougeotia sp. (Zygnemataceae). American Journal of Botany, 2010; 97 (9): 1485 DOI: 10.3732/ajb.0900341

Cite This Page:

American Journal of Botany. "Learning to live on land: How some early plants overcame an evolutionary hurdle." ScienceDaily. ScienceDaily, 22 September 2010. <www.sciencedaily.com/releases/2010/09/100915094346.htm>.
American Journal of Botany. (2010, September 22). Learning to live on land: How some early plants overcame an evolutionary hurdle. ScienceDaily. Retrieved October 20, 2014 from www.sciencedaily.com/releases/2010/09/100915094346.htm
American Journal of Botany. "Learning to live on land: How some early plants overcame an evolutionary hurdle." ScienceDaily. www.sciencedaily.com/releases/2010/09/100915094346.htm (accessed October 20, 2014).

Share This



More Plants & Animals News

Monday, October 20, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Hey, Doc! Sewage, Beer and Food Scraps Can Power Chevrolet’s Bi-Fuel Impala

Hey, Doc! Sewage, Beer and Food Scraps Can Power Chevrolet’s Bi-Fuel Impala

3BL Media (Oct. 20, 2014) Hey, Doc! Sewage, Beer and Food Scraps Can Power Chevrolet’s Bi-fuel Impala Video provided by 3BL
Powered by NewsLook.com
Captive Dolphin Gives Birth

Captive Dolphin Gives Birth

Reuters - Light News Video Online (Oct. 20, 2014) SeaWorld in San Diego welcomes a new bottlenose dolphin, the second calf for 13-year-old female, Sadie. Rough Cut. (no reporter narration). Video provided by Reuters
Powered by NewsLook.com
Another Study Suggests Viagra Is Good For The Heart

Another Study Suggests Viagra Is Good For The Heart

Newsy (Oct. 20, 2014) An ingredient in erectile-dysfunction medications such as Viagra could improve heart function. Perhaps not surprising, given Viagra's history. Video provided by Newsy
Powered by NewsLook.com
White Rhino's Death In Kenya Means Just 6 Are Left

White Rhino's Death In Kenya Means Just 6 Are Left

Newsy (Oct. 20, 2014) Suni, a rare northern white rhino at Ol Pejeta Conservancy, died Friday. This, as many media have pointed out, leaves people fearing extinction. 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:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

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