Candidate genes and molecular markers associated with heat tolerance in colonial Bentgrass

• Published in: PloS one 2017-02, Vol.12 (2), p.e0171183-e0171183
• Main Authors: Jespersen, David, Belanger, Faith C, Huang, Bingru
• Format: Article
• Language: English
• Subjects: Agrostis; Agrostis - genetics; Agrostis - metabolism; Agrostis capillaris; Agrostis stolonifera; Analysis; Antioxidants; Bentgrasses; Biodegradation; Biology and Life Sciences; Catalase; Chlorophyll; Chlorophyll content; Crop diseases; Cultivars; Cysteine proteinase; Ecology and Environmental Sciences; Electrolyte leakage; Energy metabolism; Flowers & plants; Gene expression; Genes; Genes, Plant; Genetic aspects; Genetic diversity; Genetic Markers; Genetic Variation; Genomics; Genotypes; Glutathione; Glutathione transferase; Glyceraldehyde-3-phosphate dehydrogenase; Grasses; Growth chambers; Heat; Heat shock proteins; Heat stress; Heat tolerance; Heat-Shock Proteins - genetics; Heat-Shock Proteins - metabolism; Heat-Shock Response; High temperature; Hsp70 protein; Marker-assisted selection; Markers; Metabolic pathways; Metabolism; Normalized difference vegetative index; Pathology; Phenotype; Phosphates; Physical Sciences; Physiology; Plant biology; Plant heat tolerance; Plant Proteins - genetics; Plant Proteins - metabolism; Plants (botany); Population; Proteins; Reactive oxygen species; Research and Analysis Methods; Senescence; Soil sciences; Temperature tolerance; Turf; Turfgrasses; Vegetation index
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0171183

Elevated temperature is a major abiotic stress limiting the growth of cool-season grasses during the summer months. The objectives of this study were to determine the genetic variation in the expression patterns of selected genes involved in several major metabolic pathways regulating heat tolerance for two genotypes contrasting in heat tolerance to confirm their status as potential candidate genes, and to identify PCR-based markers associated with candidate genes related to heat tolerance in a colonial (Agrostis capillaris L.) x creeping bentgrass (Agrostis stolonifera L.) hybrid backcross population. Plants were subjected to heat stress in controlled-environmental growth chambers for phenotypic evaluation and determination of genetic variation in candidate gene expression. Molecular markers were developed for genes involved in protein degradation (cysteine protease), antioxidant defense (catalase and glutathione-S-transferase), energy metabolism (glyceraldehyde-3-phosphate dehydrogenase), cell expansion (expansin), and stress protection (heat shock proteins HSP26, HSP70, and HSP101). Kruskal-Wallis analysis, a commonly used non-parametric test used to compare population individuals with or without the gene marker, found the physiological traits of chlorophyll content, electrolyte leakage, normalized difference vegetative index, and turf quality were associated with all candidate gene markers with the exception of HSP101. Differential gene expression was frequently found for the tested candidate genes. The development of candidate gene markers for important heat tolerance genes may allow for the development of new cultivars with increased abiotic stress tolerance using marker-assisted selection.