Cold stress response genes

March 17, 2025

By Shaun Bushman and Matt Robbins, USDA-ARS
 

New and improved turfgrass varieties can withstand winter damage better than the old ‘stand-by’s’. One of the projects the WinterTurf research group is working on is to find genes that contribute to this winter hardiness (Figure 1). With some recent genome assemblies in perennial ryegrass and creeping bentgrass, we can sort through the thousands of genes to find those that may help with winter hardiness.

A snow-covered lawn with snowy bushes in the foreground.
Figure 1. Between freezing and snow mold, turfgrasses have their work cutout for them each spring.

One great example is the search in the perennial ryegrass genome for a family of genes originally found during seed development called “Late Embryogenesis Abundant” or LEA genes. Some of these are critical to protect cells under cold stress, like the “cold regulated (COR)” LEA family members. Many of these LEA genes have been found in wheat and its relatives already, and searches in other plants are gaining interest. We recently finished sequencing the perennial ryegrass genome to find all the LEA/COR genes, and there are four of interest. Three of them are sitting right next to each other on chromosome 3 and a fourth is on chromosome 5 (Figure 2).

Phylogenetic tree with four branches of related genes. From top to bottom: Lpman.Chr5G5289, Lpman.Chr3G9208, Lpman.Chr3G9216, Lpman.Chr3G9219.
Figure 2. Four LEA genes that may improve cold hardiness. The three on chromosome 3 (Chr3) are closely related, near each other on the chromosome, and are induced when water deficits occur during freezing or drought situations.

Now we can select for versions of those genes that contribute to winter-hardiness to improve the survival and quality of these turfgrasses.