Navigation Links
Core mechanism for root growth identified
Date:8/25/2014

During plant growth, dividing cells in meristems must coordinate transitions from division to expansion and differentiation. Three distinct developmental zones are generated: the meristem, where the cell division takes place, and elongation and differentiation zones. At the same time, plants can rapidly adjust their direction of growth to adapt to environmental conditions.

In Arabidopsis roots, many aspects of zonation are controlled by the plant hormone auxin and auxin-induced PLETHORA transcription factors. Both show a graded distribution with a maximum near the root tip. In addition, auxin is also pivotal for tropic responses of the roots.

Ari Pekka Mhnen with his group in the Institute of Biotechnology, University of Helsinki, Finland, and Dutch colleagues has now found out with the help of experimentation and mathematical modelling how the two factors together regulate root growth.

"Cell division in the meristem is maintained by PLETHORA transcription factors. These proteins are solely transcribed in the stem cells, in a narrow region within the meristematic cells located in the tip of the root. So PLETHORA proteins are most abundant in the stem cells," Ari Pekka Mhnen says.

Outside the stem cells the amount of PLETHORA protein in the cells halves each time the cells divide. In the end there is so little PLETHORA left in the cells that they cannot stay in the dividing mode. This is when the cells start to elongate and differentiate.

Auxin is the factor taking care of many aspects of root growth. If there is enough PLETHORA in the root cells, auxin affects the rate of root cell division. If there is little or no PLETHORA in the cells, auxin regulates cell differentiation and elongation. In addition to this direct, rapid regulation, auxin also regulates cell division, expansion and differentiation indirectly and slowly by promoting PLETHORA transcription. This dual action of auxin keeps the structure and growth of the root very stable.

When PLETHORA levels gradually diminish starting from the root tip upwards, the cell division, elongation and differentiation zones are created. And this inner organisation stays even if the growth direction of the root changes.

"The gravity and other environmental factors can change the auxin content of the cells, and quite rapidly. This all affects the growth direction of the root. And of course it is important for the plant to maintain the organization while directing their roots there where water and nutrients most likely are to be found."


'/>"/>

Contact: Ari Pekka Mähönen
aripekka.mahonen@helsinki.fi
University of Helsinki
Source:Eurekalert  

Related biology news :

1. UMN and NYBC research finds potential MERS transmission mechanism between bats and humans
2. Scientists discover biochemical mechanisms contributing to fibromuscular dysplasia
3. Scientists discover new, noncommittal mechanism of drug resistance
4. Molecular mechanisms underlying the prevention of autoim-munity by Roquin revealed
5. Novel type of bird pollination mechanism discovered in South America
6. New technology reveals insights into mechanisms underlying amyloid diseases
7. Mechanism that prevents lethal bacteria from causing invasive disease is revealed
8. New from Garland Science -- now available: Cell Signaling: Principles and Mechanisms
9. The colon has a safety mechanism that restricts tumor formation
10. Researchers develop genetic control mechanism for major livestock pest
11. LSTM researchers identify the complex mechanisms controlling changes in snake venom
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Core mechanism for root growth identified
(Date:4/5/2017)... , April 4, 2017 KEY FINDINGS ... to expand at a CAGR of 25.76% during the ... is the primary factor for the growth of the ... https://www.reportbuyer.com/product/4807905/ MARKET INSIGHTS The global stem ... technology, application, and geography. The stem cell market of ...
(Date:3/30/2017)... 30, 2017  On April 6-7, 2017, Sequencing.com will ... hackathon at Microsoft,s headquarters in ... focus on developing health and wellness apps that provide ... the Genome is the first hackathon for personal ... largest companies in the genomics, tech and health industries ...
(Date:3/29/2017)... 29, 2017  higi, the health IT company that ... North America , today announced a Series B ... of EveryMove. The new investment and acquisition accelerates higi,s ... to transform population health activities through the collection and ... higi collects and secures data today on behalf ...
Breaking Biology News(10 mins):
(Date:6/19/2017)... ... June 19, 2017 , ... ... activities supporting EDETEK’s products including training, implementation, support, and client process and SOP ... role. He has previously held leadership roles for service providers and top-tier pharmaceuticals, ...
(Date:6/16/2017)... ... 16, 2017 , ... Cognition Corporation , a software ... sessions of its “From the Helm” Webinar Series. , The next two ... for design control exercises. Led by David Cronin, Cognition’s CEO, the half-hour public ...
(Date:6/15/2017)... ... June 15, 2017 , ... Cybrexa Therapeutics, a start-up ... of financing in the amount of $6 million. An investment vehicle affiliated with ... round. , The Series B funding will enable Cybrexa to complete the build-out ...
(Date:6/15/2017)... ... June 15, 2017 , ... ... new guide on how to assemble a lab workstation. The guide outlines the ... include Adam’s Nimbus or Eclipse balance, AVT anti-vibration table, OIML/ASTM certified weights, and ...
Breaking Biology Technology: