What is in this article?:
- Research findings could be important in 2,4-D resistant soybeans
- Synthetic form of auxin
• The findings suggest that application techniques which limit 2,4-D entry into soils are important to ensure production with engineered 2,4-D resistant crop plants does not require additional fertilizer and/or water inputs.

Purdue University researchers have discovered a fine-tuning mechanism involved in plant root growth that has them questioning whether a popular herbicide may have unintended consequences, causing some plants to need more water or nutrients.
Angus Murphy, a professor of horticulture, and Wendy Peer, an assistant professor of horticulture, study the movement of auxin, a plant hormone essential for plant development. They showed that ABCB4, a protein responsible for moving auxin into cells, also removes the hormone when too much has accumulated.
"We knew that the protein took auxin up, but found that it switched to removing auxin when a threshold is reached," said Murphy, whose findings appeared in the early online version of The Plant Journal. "It starts transporting the hormones out."
That fine-tuning mechanism is integral to proper development of plant root hairs, which extend from the main plant root and are where most water and minerals enter.
"The root hairs are doing all the heavy lifting for bringing the water into the plant," Peer said. "And ABCB4 maintains the right auxin levels to keep root hairs growing optimally."

