Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

Home > Press > Sensor important to understanding root, seedling development

Marshall Porterfield, at left, and Angus Murphy will be able to better understand how the plant hormone auxin regulates plant root growth and seedling establishment with a biosensor developed at Purdue University. (Purdue Agricultural Communication photo/Tom Campbell)
Marshall Porterfield, at left, and Angus Murphy will be able to better understand how the plant hormone auxin regulates plant root growth and seedling establishment with a biosensor developed at Purdue University. (Purdue Agricultural Communication photo/Tom Campbell)

Abstract:
A biosensor utilizing black platinum and carbon nanotubes developed at Purdue University will help give scientists a better understanding of how the plant hormone auxin regulates root growth and seedling establishment.

Sensor important to understanding root, seedling development

West Lafayette, IN | Posted on August 23rd, 2010

Marshall Porterfield, an associate professor of agricultural and biological engineering and biomedical engineering, created a new sensor to detect the movement of auxin along a plant's root surface in real time without damaging the plants.

The nanomaterials at the sensor's tip react with auxin and create an electrical signal that can be measured to determine the auxin concentration at a single point. The sensor oscillates, taking concentration readings at different points around a plant root. An algorithm then determines whether auxin is being released or taken in by surrounding cells.

"It is the equilibrium and transport dynamics that are important with auxin," said Porterfield, whose findings were published in the early online version of The Plant Journal.

A current focus of auxin research is understanding how this hormone regulates root growth in plants growing on sub-optimal soils. Angus Murphy, a Purdue professor of horticulture and the paper's co-author, said that worldwide pressure on land for food and energy crops drives efforts to better understand how plant roots adapt to marginal soils. Auxin is one of the major hormones involved in that adaptive growth.

"It's the key effector of these processes," Murphy said.

Although sensors using similar nanomaterials have been in use for real-time measurement of auxin levels along a root surface for several years, those earlier sensors required application of external auxin at toxic levels as part of the measurement process. Porterfield and Eric McLamore, a former Purdue postdoctoral researcher, created a new algorithm to decode the information obtained from the sensor. The algorithm processes the sensor information to show whether the hormone is moving into or out of cells. This allows the sensor to be self-referencing, eliminates the need for auxin application, and allows instantaneous and continuous measurements to be made during root growth.

Other current methods based on radioisotope tracers and auxin-responsive fluorescent proteins inserted into the plant can detect changes taking place over hours. Most auxin responses take place on a timescale of minutes.

Murphy said auxin movement is key to how plants adapt to their environments. He said that the effort to develop the sensor with Porterfield originated with the need to improve real-time measurement capability and develop a method that allows comparison with other measurements to better understand how auxin transport and other biological functions are connected.

"Using sensors like this, we can get answers that just aren't possible with existing tools," Murphy said. "Being able to measure the efflux and uptake simultaneously is really essential to a lot of ongoing work."

Murphy and Porterfield were looking for a simple model to use to test the sensor and chose an auxin transport mutant in corn. Wendy Peer, a Purdue assistant professor of horticulture and a paper co-author who studies seedling development and establishment, collaborated with Murphy in a detailed analysis of auxin transport in mutant and control corn roots using traditional methods. The information was then used to validate the sensor's functionality.

Murphy plans to continue testing on other auxin-related mutants. The National Science Foundation and the U. S. Department of Energy funded the research.

ABSTRACT

Non-invasive Quantification of Endogenous Root Auxin Transport Using an Integrated Flux Microsensor Technique

E. S. McLamore, A. Diggs, P. Calvo Marzal, J. Shi, J. J. Blakeslee, W.A. Peer,
A. S. Murphy, and D. M. Porterfield

Indole-3-acetic acid (IAA) is a primary phytohormone that regulates multiple aspects of plant development. Because polar transport of IAA is an essential determinant of organogenesis and dynamic tropic growth, methods to monitor IAA movement in vivo are in demand. A self-referencing electrochemical microsensor was optimized to non-invasively measure endogenous IAA flux near the surface of Zea mays roots without the addition of exogenous IAA. Enhanced sensor surface modification, decoupling of acquired signals, and integrated flux analyses were combined to provide direct, real time quantification of endogenous IAA movement in B73 maize inbred and brachytic2 (br2) auxin transport mutant roots. BR2 is localized in epidermal and hypodermal tissues at the root apex. br2 roots exhibit reduced shootward IAA transport at the root apex in radiotracer experiments and reduced gravitropic growth. IAA flux data indicates that maximal transport occurs in the distal elongation zone of maize roots, and net transport in/out of br2 roots was decreased compared to B73. Integration of short term real time flux data in this zone revealed oscillatory patterns, with B73 exhibiting shorter oscillatory periods and greater amplitude than br2. IAA efflux and influx were inhibited using 1-N-naphthylphthalamic acid (NPA), and 2-naphthoxyacetic acid (NOA), respectively. A simple harmonic oscillation model of these data produced a correlation between modeled and measured values of 0.70 for B73 and 0.69 for br2. These results indicate that this technique is useful for real-time IAA transport monitoring in surface tissues and that this approach can be performed simultaneously with current live imaging techniques.

####

For more information, please click here

Contacts:
Writer: Brian Wallheimer
765-496-2050


Sources: Marshall Porterfield
765-494-1190


Angus Murphy
765-496-7956


Ag Communications: (765) 494-2722;
Keith Robinson,

Copyright © Purdue University

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

News and information

Gold standards for nanoparticles: Understanding how small organic ions stabilize gold nanoparticles may allow for better control March 29th, 2017

Tiny sensor lays groundwork for precision X-rays detection via endoscopy:Nanoscale fiber-integrated X-ray sensor opens new doors for medical imaging and radiotherapy March 29th, 2017

Researchers uncover secret of nanomaterial that makes harvesting sunlight easier March 29th, 2017

Information storage with a nanoscale twist: Discovery of a novel rotational force inside magnetic vortices makes it easier to design ultrahigh capacity disk drives March 28th, 2017

Govt.-Legislation/Regulation/Funding/Policy

A big leap toward tinier lines: Self-assembly technique could lead to long-awaited, simple method for making smaller microchip patterns March 27th, 2017

Laser activated gold pyramids could deliver drugs, DNA into cells without harm: Microstructures create temporary pores in cells March 27th, 2017

Cryo-electron microscopy achieves unprecedented resolution using new computational methods March 25th, 2017

Argon is not the 'dope' for metallic hydrogen March 24th, 2017

Possible Futures

Gold standards for nanoparticles: Understanding how small organic ions stabilize gold nanoparticles may allow for better control March 29th, 2017

Tiny sensor lays groundwork for precision X-rays detection via endoscopy:Nanoscale fiber-integrated X-ray sensor opens new doors for medical imaging and radiotherapy March 29th, 2017

Researchers uncover secret of nanomaterial that makes harvesting sunlight easier March 29th, 2017

Information storage with a nanoscale twist: Discovery of a novel rotational force inside magnetic vortices makes it easier to design ultrahigh capacity disk drives March 28th, 2017

Academic/Education

AIM Photonics Welcomes Coventor as Newest Member: US-Backed Initiative Taps Process Modeling Specialist to Enable Manufacturing of High-Yield, High-Performance Integrated Photonic Designs March 16th, 2017

Nominations Invited for $250,000 Kabiller Prize in Nanoscience: Major international prize recognizes a visionary nanotechnology researcher February 20th, 2017

Oxford Nanoimaging report on how the Nanoimager, a desktop microscope delivering single molecule, super-resolution performance, is being applied at the MRC Centre for Molecular Bacteriology & Infection November 22nd, 2016

The University of Applied Sciences in Upper Austria uses Deben tensile stages as an integral part of their computed tomography research and testing facility October 18th, 2016

Nanotubes/Buckyballs/Fullerenes

Intertronics introduce new nanoparticle deagglomeration technology March 15th, 2017

Boron atoms stretch out, gain new powers: Rice University simulations demonstrate 1-D material's stiffness, electrical versatility January 26th, 2017

New stem cell technique shows promise for bone repair January 25th, 2017

Captured on video: DNA nanotubes build a bridge between 2 molecular posts: Research may lead to new lines of direct communication with cells January 9th, 2017

Sensors

Tiny sensor lays groundwork for precision X-rays detection via endoscopy:Nanoscale fiber-integrated X-ray sensor opens new doors for medical imaging and radiotherapy March 29th, 2017

“Cysteine Rose” Wins 2016 Thermo Fisher Scientific Electron Microscopy Image Contest: Thermo Fisher honors Andrea Jacassi of the Italian Institute of Technology for image of cysteine crystals using focused ion beam techniques March 27th, 2017

UC researchers use gold coating to control luminescence of nanowires: University of Cincinnati physicists manipulate nanowire semiconductors in pursuit of making electronics smaller, faster and cheaper March 17th, 2017

Optical fingerprint can reveal pollutants in the air: Researchers at Chalmers University of Technology have proposed a new, sophisticated method of detecting molecules with sensors based on ultra-thin nanomaterials March 15th, 2017

Announcements

Gold standards for nanoparticles: Understanding how small organic ions stabilize gold nanoparticles may allow for better control March 29th, 2017

Tiny sensor lays groundwork for precision X-rays detection via endoscopy:Nanoscale fiber-integrated X-ray sensor opens new doors for medical imaging and radiotherapy March 29th, 2017

Researchers uncover secret of nanomaterial that makes harvesting sunlight easier March 29th, 2017

Information storage with a nanoscale twist: Discovery of a novel rotational force inside magnetic vortices makes it easier to design ultrahigh capacity disk drives March 28th, 2017

Food/Agriculture/Supplements

Meta-lenses bring benchtop performance to small, hand-held spectrometer: Game-changing nanostructure-based lenses allow smaller devices, increased functionality February 9th, 2017

PCATDES Starts Field Testing of Photocatalytic Reactors in South East Asia December 28th, 2016

News from Quorum: The Agricultural Research Service of the USDA uses a Quorum Cryo-SEM preparation system for the study of mites, ticks and other soft bodied organisms November 22nd, 2016

Water, water -- the two types of liquid water: Understanding water's behavior could help with Alzheimer's research November 11th, 2016

NanoNews-Digest
The latest news from around the world, FREE



  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project