Photo: Hybrid plants (middle two) grow larger and more vigorously than the parents (left and right).
Scientists are slowly unravelling the complex molecular pathways that regulate growth vigor in plant hybrids, with the goal of eventually developing hybrid crops that can grow faster and more productively, while at the same time doing a better job of resisting stress such as heat, drought and pests. Many crops such as corn are grown as hybrids for better yield and traits.
In a new study out this week in the journal Proceedings of the National Academy of Sciences, researchers from The University of Texas at Austin and Peking University identified two new pathways that influence plant growth in hybrids of Arabidopsis, a weedy plant in the mustard family. One pathway works in the daytime via compounds in the circadian clock, a central regulator for plant growth; the other works at night via compounds called phytochrome interacting factors.
These two pathways work by turning up or down a hybrid plant’s production of ethylene, a hormone which inhibits vegetative growth. Because these pathways exist in all plants including most commercially important crops—such as corn, cotton, lettuce and tomatoes—altering ethylene production in these crops might boost yield too.
This project was a collaboration between four different research groups, headed by the D. J. Sibley Centennial Professor Z. Jeffrey Chen, assistant professor Hong Qiao, and professor Enamul Huq, all three in the Department of Molecular Biosciences at UT Austin; and Xing Wang Deng, professor and Dean of the School of Advanced Agriculture Sciences and School of Life Sciences at Peking University.
Chen said there are several ways the new findings of regulating plant growth vigor might be used to boost crop yields: plant breeders could do genetic tests to identify parent plants for cross breeding that reduce ethylene production; biotech companies could genetically engineer crops with lower ethylene production; or farmers could apply chemicals that inhibit ethylene production in crops growing in the field.
Photo credit: Alberto Salguero Quiles. Image used under a Creative Commons license (CC BY-SA 3.0).