WEST LAFAYETTE, Ind. - 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.
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 infor
|Contact: Brian Wallheimer|