Researchers from Washington University in St. Louis led by Richard Vierstra
describe the effects of autophagy on the metabolism of maize plants using a
uniquely comprehensive set of modern "
technologies. Autophagy is a process that helps break down damaged or
unwanted pieces of a cell so that the building blocks can be used again. In
plants, autophagy is often associated with aging, or a response to nutrient
Maize, or corn, is an important crop that is sensitive to nitrogen
deprivation. According to Vierstra, the George and Charmaine Mallinckrodt
Professor of Biology in Arts & Sciences, one of the largest costs to growing
maize in terms of energy, expenditures and farmers time is providing
adequate nitrogen to fertilize the soil.
The group learned that maize plants lacking a key gene for autophagy are
profoundly different at a molecular level - even if they're getting enough
nutrients and appear to develop normally. Using state-of-the-art tools, the
group compared and analyzed the transcriptome, proteome, metabolome, and
ionome of maize seedlings grown with or without the autophagy-related gene
ATG12, and fertilized with or without nitrogen. This allowed the team to
identify cellular processes affected by autophagy. Once considered
undiscriminating, autophagy is now considered to be highly selective, as
only certain parts of the cell are specifically recognized and reused.