Navigation Links
Convergent evolution in lignin biosynthesis: Tools for re-engineering biomass composition
Date:4/6/2010

Lignin is the double-edged sword of biofuels: if you are making cellulosic ethanol, you want less lignin because it blocks the breakdown of cellulose. If you are using pyrolytic methods, you want more lignin because lignin contains more energy than cellulose. Whether you wish to maximize or minimize lignin content, an understanding of lignin synthesis is essential and has proved elusive. Lignin is a key adaptation to life on land, as it strengthens plant cell walls thereby helping land plants stand upright and reinforcing the cell walls of the specialized water-conducting tubes that are another key adaptation to growth in terrestrial environments.

The lignin polymer is made up of a complex arrangement of subunits and its subunit composition differs among different species. For example, ferns and conifers have lignin composed mainly of p-hydroxyphenyl (H) and guaiacyl (G) lignin units. Flowering plants have H and G subunits, plus syringyl (S) subunits derived from sinapyl alcohol. Interestingly, S lignin is also found in some lycophytes, including the spikemoss Selaginella (photo). In research published this week in The Plant Cell, a team of researchers led by Clint Chapple of Purdue University showed that lignin synthesis proceeds along a different path in Selaginella. Their work centers on the characterization of the enzyme ferulate 5-hydroxylase (F5H); in flowering plants, this enzyme produces S lignin units from G lignin precursors. By comparing the Selaginella enzyme (Sm F5H) to the F5H from the model flowering plant Arabidopsis thaliana (At F5H), the authors found that Sm F5H could both catalyze the same reaction as At F5H and could also catalyze an additional reaction, acting on precursors of H lignin to form precursors to G and S lignin, and thereby bypassing four steps in angiosperm lignin synthesis. Indeed, transgenic expression of Sm F5H can restore normal lignin deposition to Arabidopsis plants with mutations in other enzymes of lignin biosynthesis. Interestingly, some combinations of transgenic Sm F5H and Arabidopsis lignin mutations produce lignin compositions likely not seen in nature, indicating that manipulation of this pathway can be used to engineer lignin composition. Moreover, since different lignin subunit compositions produce different lignin structural properties, this engineering may affect biomass characteristics such as digestibility. Author Clinton Chapple notes "It is exciting to realize that the study of plants so distantly related to crops can provide us with new tools to engineer plants that are of benefit to humans."

This research also provides interesting insights on convergent evolution, the process whereby different evolutionary lineages arrive at similar adaptations, such as the independent evolution of wings for flight in bats and birds. Selaginella is part of one of the oldest divisions of vascular plants, resulting from an ancient split between the lycophytes and euphyllophytes (which include all modern seed plants). Similar to bat wings and bird wings, the synthesis of S lignin appears to have arisen independently in flowering plants and in lycophytes. Thus, this research provides both an interesting window on convergent evolution in plants and a potentially useful tool for engineering lignin synthesis.


'/>"/>

Contact: Jennifer Mach
jmach@aspb.org
773-368-8021
American Society of Plant Biologists
Source:Eurekalert  

Related biology news :

1. NAS announces visual culture and evolution online symposium
2. Queens University professors chemistry discovery may revolutionize cooking oil production
3. Understanding Climates Influence on Human Evolution -- March 31 public event
4. Major report reveals the environmental and social impact of the livestock revolution
5. Students perceptions of Earths age influence acceptance of human evolution, says U of Minn. study
6. Stickleback genomes shining bright light on evolution
7. Scientists reveal driving force behind evolution
8. Intelligent people have unnatural preferences and values that are novel in human evolution
9. Michigan State uses NSF grant to study evolution in action
10. Evolutionary game of rock-paper-scissors may lead to new species
11. Cameras of the future: heart researchers create revolutionary photographic technique
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Convergent evolution in lignin biosynthesis: Tools for re-engineering biomass composition
(Date:3/29/2017)... CHICAGO , March 29, 2017  higi, the ... ecosystem in North America , today ... Partners and the acquisition of EveryMove. The new investment ... extensive set of tools to transform population health activities ... and lifestyle data. higi collects and secures ...
(Date:3/24/2017)... -- The Controller General of Immigration from Maldives Mr. ... have received the prestigious international IAIR Award for the most innovative high ... ... Maldives Immigration Controller ... (small picture on the right) have received the IAIR award for the ...
(Date:3/23/2017)... , Mar. 23, 2017 Research and Markets ... Market Analysis & Trends - Industry Forecast to 2025" report ... ... at a CAGR of around 8.8% over the next decade to ... report analyzes the market estimates and forecasts for all the given ...
Breaking Biology News(10 mins):
(Date:5/26/2017)... Linda, Ca (PRWEB) , ... May 25, 2017 ... ... to truly understanding the full process behind each occurrence. Live cell imaging using ... In this webinar, the use of automated fluorescence microscopy methods will be discussed, ...
(Date:5/24/2017)... Washington, and WASHINGTON, DC, USA (PRWEB) , ... May 23, 2017 ... ... driver of the economy as well as an enabler of life-saving medical and other ... for optics and photonics . They joined others in the scientific community today in ...
(Date:5/23/2017)... ... May 23, 2017 , ... ... unlimited source of human cardiovascular cells for research and the development of ... it possible to generate large numbers of cardiomyocytes (hPSC-CMs). Due to varying ...
(Date:5/23/2017)... , ... May 23, 2017 , ... ... advanced technology applications, has announced a facility expansion to accommodate its rapid growth. ... feet of new workspace and renovation of the existing areas. The expansion includes, ...
Breaking Biology Technology: