Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Core mechanism for root growth identified

25.08.2014

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.

Root Growth

Cell division in the root meristem is maintained by PLETHORA transcription factors solely transcribed in the stem cells. 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 and start to elongate and differentiate.

Credit: Ari Pekka Mähönen group, Institute of Biotechnology

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 Mähönen 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 Mähönen 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."

Ari Pekka Mähönen | Eurek Alert!
Further information:
http://www.helsinki.fi

Further reports about: Core Helsinki elongation gravity identified mechanism nutrients proteins root structure

More articles from Life Sciences:

nachricht Zebrafish's near 360 degree UV-vision knocks stripes off Google Street View
22.06.2018 | University of Sussex

nachricht New cellular pathway helps explain how inflammation leads to artery disease
22.06.2018 | Cedars-Sinai Medical Center

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Temperature-controlled fiber-optic light source with liquid core

In a recent publication in the renowned journal Optica, scientists of Leibniz-Institute of Photonic Technology (Leibniz IPHT) in Jena showed that they can accurately control the optical properties of liquid-core fiber lasers and therefore their spectral band width by temperature and pressure tuning.

Already last year, the researchers provided experimental proof of a new dynamic of hybrid solitons– temporally and spectrally stationary light waves resulting...

Im Focus: Overdosing on Calcium

Nano crystals impact stem cell fate during bone formation

Scientists from the University of Freiburg and the University of Basel identified a master regulator for bone regeneration. Prasad Shastri, Professor of...

Im Focus: AchemAsia 2019 will take place in Shanghai

Moving into its fourth decade, AchemAsia is setting out for new horizons: The International Expo and Innovation Forum for Sustainable Chemical Production will take place from 21-23 May 2019 in Shanghai, China. With an updated event profile, the eleventh edition focusses on topics that are especially relevant for the Chinese process industry, putting a strong emphasis on sustainability and innovation.

Founded in 1989 as a spin-off of ACHEMA to cater to the needs of China’s then developing industry, AchemAsia has since grown into a platform where the latest...

Im Focus: First real-time test of Li-Fi utilization for the industrial Internet of Things

The BMBF-funded OWICELLS project was successfully completed with a final presentation at the BMW plant in Munich. The presentation demonstrated a Li-Fi communication with a mobile robot, while the robot carried out usual production processes (welding, moving and testing parts) in a 5x5m² production cell. The robust, optical wireless transmission is based on spatial diversity; in other words, data is sent and received simultaneously by several LEDs and several photodiodes. The system can transmit data at more than 100 Mbit/s and five milliseconds latency.

Modern production technologies in the automobile industry must become more flexible in order to fulfil individual customer requirements.

Im Focus: Sharp images with flexible fibers

An international team of scientists has discovered a new way to transfer image information through multimodal fibers with almost no distortion - even if the fiber is bent. The results of the study, to which scientist from the Leibniz-Institute of Photonic Technology Jena (Leibniz IPHT) contributed, were published on 6thJune in the highly-cited journal Physical Review Letters.

Endoscopes allow doctors to see into a patient’s body like through a keyhole. Typically, the images are transmitted via a bundle of several hundreds of optical...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Munich conference on asteroid detection, tracking and defense

13.06.2018 | Event News

2nd International Baltic Earth Conference in Denmark: “The Baltic Sea region in Transition”

08.06.2018 | Event News

ISEKI_Food 2018: Conference with Holistic View of Food Production

05.06.2018 | Event News

 
Latest News

Graphene assembled film shows higher thermal conductivity than graphite film

22.06.2018 | Materials Sciences

Fast rising bedrock below West Antarctica reveals an extremely fluid Earth mantle

22.06.2018 | Earth Sciences

Zebrafish's near 360 degree UV-vision knocks stripes off Google Street View

22.06.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>