Featured Research

from universities, journals, and other organizations

New control pathways in synthesis of plant chemical defences

Date:
December 17, 2013
Source:
Universidad de Barcelona
Summary:
A scientific study reveals a new mechanism to control saponin biosynthesis. Saponins are essential in the adaptation of many plants to the environment and have high biomedical and industrial interest.

The new research is focused on the plant Medicago truncatula, a legume used as a model in physiological and molecular studies.
Credit: Karel Spruyt, VIB).

A scientific study reveals a new mechanism to control saponin biosynthesis. Saponins are essential in the adaptation of many plants to the environment and have high biomedical and industrial interest. The article was recently published in the journal Nature. Professor Narciso Campos, from the Faculty of Biology of the University of Barcelona, participates in the international study led by the expert Alain Goossens from the Flanders Institute for Biotechnology (VIB, Belgium).

Secondary metabolites: defense and adaptation to the environment

The study analyses the synthesis of saponins, a group of secondary metabolites found in many plants. Saponins defend plants against environmental aggressions (pathogens, herbivores, etc.), by altering membrane permeability, and have importance in pharmaceutical and industrial sectors as antimicrobial, anticancer and haemolytic agents.

Saponins derive from the isoprenoid (terpenoid) biosynthetic pathway, a metabolic route in which the HMGR (3-hydroxy-3-methylglutaryl-CoA reductase) enzyme plays key role. As Professor Narciso Campos mentions, "HMGR was identified four decades ago in mammals, and a few years later in plants and fungi. In the case of humans, it has a key regulatory role in the synthesis of cholesterol, the imbalance of which causes severe abnormalities, such as atherosclerosis. In the case of plants and fungi, the enzyme plays also a crucial role in sterol biosynthesis. Because its biomedical interest, isoprenoid biosynthesis is the subject with the highest number of Nobel Prizes."

A molecular brake in saponin biosynthesis

The new research is focused on the plant Medicago truncatula, a legume used as a model in physiological and molecular studies. When plants detect an external challenge, massive accumulation of saponins is triggered by the phytohormone methyl jasmonate. More precisely, this biochemical signal induces different isoforms of the enzyme HMGR and, subsequently, the synthesis of the defensive saponins. As proposed in the published work, there is brake for this metabolic cascade which was unknown to date: E3 ubiquitin ligase; it negatively regulates HMGR activity and, consequently, saponin synthesis.

"Ubiquitin ligase is a subunit of the protein degradation system ubiquitin-proteasome system. which recognises the molecular target to be degraded. In protein biology, degradative processes are as important as biosynthetic ones. In fact, many human diseases are due to the accumulation of proteins which have not been conveniently degraded," points out Narciso Campos, member of the Research Group Plant Molecular Genetics of UB and the Centre for Research in Agricultural Genomics (CRAG).

A highly complex pathway in plants

Unlike other organisms, plants have a highly complex isoprenoid biosynthetic pathway. To date, around 35,000 isoprenoid compounds, most from plants, have been described. The identified compounds, which are only a part of those present in nature, have an extraordinary biotechnological and industrial potential. Isoprenoids are essential for many plant functions (respiration, photosynthesis, development, cell organization, etc.) and for the plant interaction with the environment (defense, insect attraction, etc.). "Each group of plants has its particular set of isoprenoids," explains Narciso Campos.

Progress in the elucidation of isoprenoid biosynthetic pathway, in plants, opens new paths in the research of cholesterol metabolism. Yeast, mammal and plant HMGR have a bipartite structure formed by the catalytic domain and a membrane domain inserted in the endoplasmic reticulum. Several studies have shown that the expression of the HMGR membrane domain leads to massive accumulation of endoplasmic reticulum membranes. Narciso Campos points out that this has been maintained through evolution and could be related to the control of sterol biosynthesis.


Story Source:

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


Journal Reference:

  1. Jacob Pollier, Tessa Moses, Miguel González-Guzmán, Nathan De Geyter, Saskia Lippens, Robin Vanden Bossche, Peter Marhavý, Anna Kremer, Kris Morreel, Christopher J. Guérin, Aldo Tava, Wieslaw Oleszek, Johan M. Thevelein, Narciso Campos, Sofie Goormachtig, Alain Goossens. The protein quality control system manages plant defence compound synthesis. Nature, 2013; 504 (7478): 148 DOI: 10.1038/nature12685

Cite This Page:

Universidad de Barcelona. "New control pathways in synthesis of plant chemical defences." ScienceDaily. ScienceDaily, 17 December 2013. <www.sciencedaily.com/releases/2013/12/131217085223.htm>.
Universidad de Barcelona. (2013, December 17). New control pathways in synthesis of plant chemical defences. ScienceDaily. Retrieved October 23, 2014 from www.sciencedaily.com/releases/2013/12/131217085223.htm
Universidad de Barcelona. "New control pathways in synthesis of plant chemical defences." ScienceDaily. www.sciencedaily.com/releases/2013/12/131217085223.htm (accessed October 23, 2014).

Share This



More Plants & Animals News

Thursday, October 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Working Mother DIY: Pumpkin Pom-Pom

Working Mother DIY: Pumpkin Pom-Pom

Working Mother (Oct. 22, 2014) — How to make a pumpkin pom-pom. Video provided by Working Mother
Powered by NewsLook.com
San Diego Zoo's White Rhinos Provide Hope for the Critically Endangered Species

San Diego Zoo's White Rhinos Provide Hope for the Critically Endangered Species

Reuters - Light News Video Online (Oct. 22, 2014) — The pair of rare white northern rhinos bring hope for their species as only six remain in the world. Elly Park reports. Video provided by Reuters
Powered by NewsLook.com
Raw: Bear Cub Strolls Through Oregon Drug Store

Raw: Bear Cub Strolls Through Oregon Drug Store

AP (Oct. 22, 2014) — Shoppers at an Oregon drug store were surprised by a bear cub scurrying down the aisles this past weekend. (Oct. 22) Video provided by AP
Powered by NewsLook.com
Family Pleads for Pet Pig to Stay at Home

Family Pleads for Pet Pig to Stay at Home

AP (Oct. 22, 2014) — The Johnson family lost their battle with the Chesterfield County, Virginia Planning Commission to allow Tucker, their pet pig, to stay in their home, but refuse to let the board keep Tucker away. (Oct. 22) Video provided by AP
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