A new and reliable way to detect frost tolerance in Pooideae plants

Abstract

The morphological markers of plant-stress tolerance are often evaluated as having essential limitations: a continuous reaction to the environmental fluctuations and their excessive influence on each other. To avoid these limitations, the authors propose a new strategy for searching for markers, based on the identification of macro-traits related with adaptive growth bifurcation. The later manifests itself in roots as a sharp decline of meristem cell production at ~ 4 °C. It has been detected that under the hardening regime, the length of root growth zone of stress-tolerant Festuca pratensis is significantly shorter than that of less stress-tolerant Lolium multiflorum and Festulolium braunii. Using a quantitative approach, it was determined that this decrease in cell production results in the sharp decrease of growing cells number and also strongly reduces the growth zone length. Besides this, during the hardening regime, the length dynamics of F. pratensis root hairs was significantly higher than that of other species. This effect is caused by meristem bifurcation, which determines the rare release of cells from the growth zone, thus, the previous root hairs increase significantly. The proposed bifurcation-related markers seem to withstand these limitations and could be applied in plant breeding and the ecological evaluation of plants.