Nanotechnology Now

Our NanoNews Digest Sponsors





Heifer International

Wikipedia Affiliate Button


android tablet pc

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

Iran to Hold 3rd Int'l Engineering Materials, Metallurgy Conference October 25th, 2014

Haydale Secures Exclusive Development and Supply Agreement with Tantec A/S: New reactors to be built and commissioned by Tantec A/S represent another step forward towards the commercialisation of graphene October 24th, 2014

QuantumWise guides the semiconductor industry towards the atomic scale October 24th, 2014

SUNY Polytechnic Institute Invites the Public to Attend its Popular Statewide 'NANOvember' Series of Outreach and Educational Events October 23rd, 2014

Govt.-Legislation/Regulation/Funding/Policy

Novel Rocket Design Flight Tested: New Rocket Propellant and Motor Design Offers High Performance and Safety October 23rd, 2014

Strengthening thin-film bonds with ultrafast data collection October 23rd, 2014

Brookhaven Lab Launches Computational Science Initiative:Leveraging computational science expertise and investments across the Laboratory to tackle "big data" challenges October 22nd, 2014

Bipolar Disorder Discovery at the Nano Level: Tiny structures found in brain synapses help scientists better understand disorder October 22nd, 2014

Possible Futures

Imaging electric charge propagating along microbial nanowires October 20th, 2014

Superconducting circuits, simplified: New circuit design could unlock the power of experimental superconducting computer chips October 18th, 2014

Nanocoatings Market By Product Is Expected To Reach USD 8.17 Billion By 2020: Grand View Research, Inc. October 15th, 2014

Perpetuus Carbon Group Receives Independent Verification of its Production Capacity for Graphenes at 140 Tonnes per Annum: Perpetuus Becomes the First Manufacturer in the Sector to Allow Third Party Audit October 7th, 2014

Academic/Education

SUNY Polytechnic Institute Invites the Public to Attend its Popular Statewide 'NANOvember' Series of Outreach and Educational Events October 23rd, 2014

First Canada Excellence Research Chair gets $10 million from the federal government for oilsands research at the University of Calgary: Federal government announces prestigious research chair to study improving oil production efficiency October 19th, 2014

Raytheon, UMass Lowell open on-campus research institute: Industry leaderís researchers to collaborate with faculty, students to move key technologies forward through first-of-its-kind partnership October 11th, 2014

SUNY Colleges of Nanoscale Science and Engineering and National Institute for Occupational Safety and Health Announce Expanded Partnership October 2nd, 2014

Nanotubes/Buckyballs

Materials for the next generation of electronics and photovoltaics: MacArthur Fellow develops new uses for carbon nanotubes October 21st, 2014

Special UO microscope captures defects in nanotubes: University of Oregon chemists provide a detailed view of traps that disrupt energy flow, possibly pointing toward improved charge-carrying devices October 21st, 2014

Imaging electric charge propagating along microbial nanowires October 20th, 2014

Beyond LEDs: Brighter, new energy-saving flat panel lights based on carbon nanotubes - Planar light source using a phosphor screen with highly crystalline single-walled carbon nanotubes (SWCNTs) as field emitters demonstrates its potential for energy-efficient lighting device October 14th, 2014

Sensors

MEMS & Sensors Technology Showcase: Finalists Announced for MEMS Executive Congress US 2014 October 23rd, 2014

Journal Nanotechnology Progress International (JONPI), 2014, Volume 5, Issue 1, pp 1-24 October 22nd, 2014

Imaging electric charge propagating along microbial nanowires October 20th, 2014

Graphenea opens US branch October 16th, 2014

Announcements

Iran to Hold 3rd Int'l Engineering Materials, Metallurgy Conference October 25th, 2014

Haydale Secures Exclusive Development and Supply Agreement with Tantec A/S: New reactors to be built and commissioned by Tantec A/S represent another step forward towards the commercialisation of graphene October 24th, 2014

QuantumWise guides the semiconductor industry towards the atomic scale October 24th, 2014

Strengthening thin-film bonds with ultrafast data collection October 23rd, 2014

Food/Agriculture/Supplements

Smallest world record has 'endless possibilities' for bio-nanotechnology October 8th, 2014

Simple Detection of Toxic Compounds in Dairy Products October 6th, 2014

Iranian Scientists Separate Zinc Ion at Low Concentrations September 20th, 2014

Nanoscience makes your wine better September 17th, 2014

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







© Copyright 1999-2014 7th Wave, Inc. All Rights Reserved PRIVACY POLICY :: CONTACT US :: STATS :: SITE MAP :: ADVERTISE