Analysis of Camelina sativa transcriptomes identified specific transcription factors and processes associated with freezing tolerance in a winter biotype

Authors: Anderson, James; NEUBAUER, MCKAYLA - North Dakota State University; Horvath, David; Chao, Wun; BERTI, MARISOL - North Dakota State University

Submitted to: Industrial Crops and Products
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/11/2021
Publication Date: 12/23/2021
Citation: Anderson, J.V., Neubauer, M., Horvath, D.P., Chao, W.S., Berti, M.T. 2021. Analysis of Camelina sativa transcriptomes identified specific transcription factors and processes associated with freezing tolerance in a winter biotype. Industrial Crops and Products. 177. Article 114414. https://doi.org/10.1016/j.indcrop.2021.114414.
DOI: https://doi.org/10.1016/j.indcrop.2021.114414

Interpretive Summary: Camelina is an oilseed crop consisting of both spring- and winter-biotypes. Unlike spring biotypes that generally do not survive long-term freezing conditions, winter biotypes of camelina can survive the harsh winter conditions of the northern Great Plains and are valued as cover crop options. In this study, we compared a spring- and winter-biotype of camelina and identified a small number of genes that are turned on or off in each biotype and are suspected of influencing processes known to impact freezing tolerance. The results of this study highlight important information regarding regulation of cold-induced freezing tolerance at the molecular level, which should provide a starting point for engineering or breeding of climate-resilient crops for sustainable agricultural intensification under a changing climate.

Technical Abstract: Camelina (Camelina sativa L., Crantz) is an oilseed crop consisting of both spring- and winter-biotypes. Winter biotypes of camelina need a low-temperature treatment to acquire freezing tolerance and floral competence. However, spring biotypes do not require a low-temperature treatment to initiate flowering and do not cold acclimate to the same extent as winter biotypes. Exposure of the camelina winter biotype ‘Joelle’ to low temperature (5 C) for 0-, 1-, 2-, 4-, and 6-weeks resulted in freezing survival rates of ~ 0, 0, 20, 36, and 72%, respectively, after being exposed to freezing conditions (-15 C for 4 h). Winter biotype plants that survived the freezing treatment (42 d post-treatment under greenhouse conditions) also flowered; however, time to flowering was dependent on the cold treatment duration. Plants exposed to 5 C for six weeks flowered first followed in order by plants exposed to 4- and 2-weeks cold. To decipher molecular regulation associated with low-temperature acquired freezing tolerance and floral competence in camelina, we analyzed the transcriptomes of a spring- (CO46) and winter- (Joelle) biotype exposed to 0-, 1-, 2-, 4-, 6- and 8-weeks low temperature (5 C). Genes and transcription factors with significant differential abundance (4-fold up or down) between the winter- and spring-biotypes of camelina were used to identify those over-represented among gene ontologies. The results highlighted gene ontologies associated with abiotic and biotic defense responses, oxidative stress responses, cell wall modification and cell expansion, biosynthesis of lipids and very long chain fatty acids, anthocyanins, as well as processes involving photosynthesis, sugar metabolism, transport, and abscisic acid (ABA), auxin, jasmonic acid (JA), and salicylic acid (SA) signaling. Potential regulators of these processes may include cold acclimation responsive transcripts identified in the winter biotype of camelina that are similar to Arabidopsis transcription factors MYB47, MYB75 and MYB90, NF-YA4 and NF-YB2, HAT1, GRF7, CKG, and CBF1 and CBF2.