By Blake Jackson
Researchers at Penn State have identified a group of naturally occurring corn traits that could help breeders develop more drought-tolerant hybrids.
The study, published in Crop Science, found that certain corn plants possess longer metaxylem vessel elements—tube-like structures within the plant’s xylem tissue—that improve water movement from the roots to the leaves.
The research team discovered that these longer vessel elements are linked to rapidly growing, deeper root systems that allow plants to access moisture deeper in the soil.
Together, these characteristics create what researchers describe as the “stretch phenotype,” a combination of traits associated with stronger water transport, improved water uptake, and better crop performance during drought.
“Drought is a primary limitation for crop production and is projected to worsen due to climate change,” said study senior author Jonathan Lynch, distinguished professor of plant nutrition in the Penn State College of Agricultural Sciences.
“Understanding and managing crop drought tolerance is an urgent priority for global agriculture. This study shows that corn plants with longer xylem vessel elements move water more efficiently, grow deeper roots, access deeper soil moisture and produce better yields during drought.”
The team evaluated hundreds of genetically diverse corn plants and found significant differences in xylem vessel length.
Plants with longer vessel elements also had lower perforation plate height, reducing resistance to water flow and creating a more efficient transport system.
“Think of it like this — short pipes with many barriers result in slower flow and conversely, long, smooth pipes conduct faster flow,” Lynch explained. “The perforation plates are like tiny partitions between xylem cells. Smaller/lower barriers mean less resistance to water flow. So, longer xylem vessel elements create a more efficient water-transport system.”
Researchers confirmed their findings through greenhouse experiments, field trials in Pennsylvania and Chile, and computer simulations. Genetic analysis also identified DNA markers linked to the stretch phenotype, suggesting these beneficial traits are inherited.
“The seed companies are always interested in traits that can be used to breed better crops, and certainly drought is the biggest risk to crop production anywhere on Earth, including in rich countries like the U.S.,” Lynch said.
“Farmers do not usually irrigate corn, so they’re depending on the climate, which is quite variable. For example, this year significant parts of the U.S. corn belt have been pretty dry. So, anything we can do to improve corn’s ability to withstand drought would be important. The findings from this research identify a potential avenue to breed more drought-tolerant crops.”
Photo Credit: getty-images-alinamd
Categories: Pennsylvania, Crops, Corn, Weather