|FUCHS, SAM - Washington State University|
Submitted to: Heliyon
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/6/2017
Publication Date: 9/6/2017
Citation: Landry, E.J., Fuchs, S.J., Bradley, V.L., Johnson, R.C. 2017. The effect of cold acclimation on the low molecular weight carbohydrate composition of safflower. Heliyon. 3(2017)e00402. https://doi.org/10.1016/j.heliyon.2017.e00402.
Interpretive Summary: Safflower is one of the most important temperate oil crops in the world. Both winter and spring types are grown in many countries but testing and selection in North America of winter type safflower is limited. Utilizing the National Plant Germplasm System, winter safflower lines were selected and three were released with adequate winterhardiness for southeastern Washington growing conditions. In order to further characterize why these winter-type safflower lines are substantially more winterhardy than spring-type materials, we sought to understand the metabolic adaptations the safflower seedling undergoes during cold acclimation. This report highlights the response of low molecular weight carbohydrates (fructose, glucose, sucrose, raffinose, stachyose, and verbascose) within leaf, stem, and root tissue of safflower seedlings grown for four weeks at 4°C as compared to growth for two weeks at 20°C. The increase in concentration of fructose and glucose of leaf tissue best distinguishes winter from spring-types. Further characterization will be necessary to separate winter-type lines with varying levels of winterhardiness.
Technical Abstract: Understanding the effect of cold acclimation on and identification of the low molecular weight carbohydrates that support the development of freezing tolerant safflower seedlings will aid in breeding winter-hardy cultivars for temperate cropping systems. Three field selected lines of winter safflower (WSRC01: PI 651878; WSRC02: PI 651879; WSRC03: PI 651880) were cold acclimated for four weeks at 4°C and compared to seedlings grown for two weeks at 20°C. The commercial spring-type cultivar, Olé, served as a non-hardy check. Leaf, stem, and root fructose, glucose, sucrose, raffinose, and stachyose concentrations all increased to variable extents across the PI accessions. In comparison with Olé these accessions tended to be more responsive to cold acclimation by increasing the concentrations of these metabolites. Verbascose was only recovered within leaf tissue and PI 651880 was the only entry to show a substantial alteration in concentration due to cold acclimation. Based on these data, a specific low molecular weight carbohydrate is not responsive or responsible for the accumulation of freezing tolerance, but a concert of metabolites and their responsiveness may help explain the observed differences in development, freezing tolerance, and ultimately, winterhardiness among safflower germplasm.