Navigation Links
Sugar pump in plants identified

This release is available in German.

Plants must supply their various tissues with the carbohydrates they produce through photosynthesis in the leaves. However, they do not have a muscular pump like the human heart to help transport this vital fuel. Instead, they use pump proteins in their cell membranes for this purpose. Together with colleagues from the Carnegie Institution for Science in California, Alisdair Fernie from the Max Planck Institute of Molecular Plant Physiology in Potsdam has identified a hitherto unknown protein in the carbohydrate transport chain. The researchers' discovery could help to protect plants against pests and increase harvest yields.

Vascular pathways consisting of interconnected cells act as a system for the transport of carbohydrates in plants. Phloem, the tissue that carries the nutrients, consists of, among other things, the actual conducting cells, which are also known as sieve elements, as well as the surrounding companion and phloem parenchyma cells. Carbohydrates are mainly transported in the phloem in the form of sucrose. The cell membrane of the sieve cells contains pump proteins that actively convey sucrose into the vascular pathways. Up to now it was unclear how the sucrose travelled from the parenchyma cells to the transport pumps, the sieve elements. Thus, information about an important element in the transport chain was missing.

With the participation of the Max Planck Institute of Molecular Physiology, a research group at the Carnegie Institution for Science in Stanford, USA, has now succeeded in identifying this previously unknown sucrose transporter. Different proteins are involved here which belong to the recently identified protein family known as SWEET. The SWEETs arise in the cell membrane of the phloem parenchyma cells. They act as molecular pumps that convey the sucrose out of the parenchyma cells and forward it to a second transport system - identified by the group 20 years ago - which feeds the sucrose into the actual phloem conducting cells.

In their studies, the researchers examined sucrose transport in the thale cress, Arabidopsis thaliana, and in rice plants. In order to track down the function of the SWEET proteins, they switched off the corresponding genes in a series of plants. This enabled them to discover that, when their SWEETs do not work, plants have a considerably higher sucrose content in their leaves. "Because the sugar cannot be transported away, it accumulates in the leaf tissue, and other parts of the plant, like the roots and seeds, do not receive an adequate supply of sucrose," explains Alisdair Fernie from the Potsdam-based Max Planck Institute.

This discovery represents an important development for plant breeding as, in many cases, the parts of plants used by humans, like seeds and tubers, do not form any carbohydrates themselves but are, instead, supplied by the leaves. "We can now regulate these molecular pumps precisely and thereby increase the transport of sucrose to the plant seeds. One day, it may be possible to increase the harvest yield of agricultural crops in this way," explains Wolf Frommer from the Carnegie Institution. Moreover, the SWEETs provide a promising starting point for the protection of plants against pest infestations. Some pests, for example the bacterium Xanthomonas oryzae, which causes leaf streak in rice, misuse these transporters to access the plant's sucrose and feed on it themselves. For this reason, the scientists would now like to clarify the role of these transporters in pest infestation in greater detail.

The researchers suspect, moreover, that the corresponding pump proteins have a similar function in humans and animals. If confirmed, this would constitute a very important discovery for diabetes and obesity research, as the identity of the protein responsible for the transport of carbohydrate from the intestine into the blood and from liver cells is not yet known.


Contact: Alisdair Fernie

Related biology news :

1. 3 p.m. slump? Why a sugar rush may not be the answer
2. Sugar-sweetened beverages may increase cardiovascular risk in women
3. Einstein study indicates brain plays role in regulating blood sugar in humans
4. Sexual selection by sugar molecule helped determine human origins
5. Targeting HIVs sugar coating
6. Novel gene increases yeasts appetite for plant sugars
7. Pocket chemistry: DNA helps glucose meters measure more than sugar
8. Sugar-based chemicals book chapter by NJIT professor takes ACS kudos
9. Sugar helping map new ground against deadly bug
10. Sugarcane cools climate
11. Sugarcane bioethanol: Environmental implications
Post Your Comments:
(Date:4/28/2016)... and BANGALORE, India , April 28, ... Systems, a product subsidiary of Infosys (NYSE: INFY ... announced a global partnership that will provide end ... use mobile banking and payment services.      (Logo: ... key innovation area for financial services, but it also plays ...
(Date:4/15/2016)... CHICAGO , April 15, 2016  A ... companies make more accurate underwriting decisions in a ... offering timely, competitively priced and high-value life insurance ... health screenings. With Force Diagnostics, rapid ... and lifestyle data readings (blood pressure, weight, pulse, ...
(Date:3/31/2016)... , March 31, 2016  Genomics firm Nabsys has ... CEO, Barrett Bready , M.D., who returned to ... the original technical leadership team, including Chief Technology Officer, ... Product Development, Steve Nurnberg and Vice President of Software ... the company. Dr. Bready served as CEO ...
Breaking Biology News(10 mins):
(Date:6/23/2016)... ... June 23, 2016 , ... UAS LifeSciences, one of the ... brand, UP4™ Probiotics, into Target stores nationwide. The company, which has been manufacturing ... to its list of well-respected retailers. This list includes such fine stores as ...
(Date:6/23/2016)... ... June 23, 2016 , ... ... (Yeast and Mold) microbial test has received AOAC Research Institute approval 061601. , ... tests introduced last year,” stated Bob Salter, Vice President of Regulatory and Industrial ...
(Date:6/23/2016)... ... June 23, 2016 , ... STACS DNA Inc., the sample ... the Arkansas State Crime Laboratory, has joined STACS DNA as a Field Application Specialist. ... said Jocelyn Tremblay, President and COO of STACS DNA. “In further expanding our capacity ...
(Date:6/23/2016)... NEW YORK , June 23, 2016 ... the trading session at 4,833.32, down 0.22%; the Dow Jones ... the S&P 500 closed at 2,085.45, down 0.17%. has ... INFI ), Nektar Therapeutics (NASDAQ: NKTR ... BIND Therapeutics Inc. (NASDAQ: BIND ). Learn more ...
Breaking Biology Technology: