Location: Forage and Range ResearchTitle: Transcript responses to drought in Kentucky bluegrass (Poa pratensis L.) germplasm varying in their tolerance to drought stress
Submitted to: Environmental and Experimental Botany
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/25/2021
Publication Date: 6/30/2021
Citation: Bushman, B.S., Robbins, M.D., Thorsted, K., Robins, J.G., Warnke, S.E., Martin, R.C., Harris-Shultz, K.R. 2021. Transcript responses to drought in Kentucky bluegrass (Poa pratensis L.) germplasm varying in their tolerance to drought stress. Environmental and Experimental Botany. 190. Article 104571. https://doi.org/10.1016/j.envexpbot.2021.104571.
Interpretive Summary: For the cool-season turfgrass Kentucky bluegrass, improving germplasm for drought tolerance is an increasingly important priority. In this papaer we characterized gene expression responses to drought in several Kentucky bluegrass germplasm sources that differed in their ability to tolerate drought stress. We found that gene transcripts that made chaperone proteins, whose job it is to protect protein folding and transport, played a large role in drought response and drought tolerance. Two of those, RAB15 and HVA1, would be ideal target for further selection and optimization for Kentucky bluegrass drought tolerance.
Technical Abstract: For the cool-season turfgrass Kentucky bluegrass, improving germplasm for drought tolerance is an increasingly important priority. Although genetic mechanisms behind drought tolerance have been characterized for model and agronomic plant species, the critical genes, gene families, and transcript isoforms important in Kentucky bluegrass are unclear. Using an RNAseq across three germplasm sources that differ in their drought responses, we have identified transcript isoforms related to a shared response of all three germplasm sources to drought stress and a tolerance response where the more drought-tolerant germplasm sources exhibited higher transcript differences compared to the drought-susceptible cultivar Midnight. Annotation and transcript profile groupings both identified chaperone gene families with protein folding and protective functions, such as heat shock proteins, DNAj, and late embryogenesis abundant genes. Transcript isoforms within these gene families were tolerance related and known to respond to absissic acid. Two dehydrin genes, RAB15 and HVA1, were further induced in more drought-tolerant germplasm and show promise as candidate genes for selection.