Micro-enzymatic evaluation of oat (Avena sativa L.) beta-glucan for high-throughput phenotyping

Authors: NEWELL, MARK - Iowa State University; KIM, HYUN JUNG - Jeju National University; ASORO, FRANCO - Iowa State University; Moran Lauter, Adrienne; WHITE, PAMELA - Iowa State University; Scott, Marvin; Jannink, Jean-Luc

Submitted to: Cereal Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/19/2013
Publication Date: 4/1/2014
Citation: Newell, M.A., Kim, H., Asoro, F.G., Moran Lauter, A., White, P.J., Scott, M.P., Jannink, J. 2014. Micro-enzymatic evaluation of oat (Avena sativa L.) beta-glucan for high-throughput phenotyping. Cereal Chemistry. 91:183–188.

Interpretive Summary: Oats contain beta glucans that are widely recognized for their health benefits, including reducing serum cholesterol concentrations. Including oats in foods has been shown to reduce heart disease, one of the most important health issues in the United States. Increasing the beta glucan content of oats would increase these health benefits. This can be done by breeding, but such efforts have been limited by the ability to measure beta glucan content rapidly and inexpensively. We have developed a method for measuring beta glucan content that reduces costs by 90% and requires 5% of the time required by other methods, while still producing results that are similar to a standard method. This work will enable plant breeders to increase the beta glucan content of oats more rapidly and with less cost and effort, resulting in oat varieties with increased health benefits for consumers.

Technical Abstract: Oat, a grass species grown predominantly in temperate short-season regions, has received significant attention for its positive and consistent health benefits when consumed as a whole grain food. These positive health benefits can be attributed to mixed-linkage (1-3, 1-4)-ß-D-glucan (referred to as ß-glucan), a soluble dietary fiber found in cereal endosperm cell walls. As a result of its positive impact on human health, ß-glucan content has become a major focus of oat breeding operations. Unfortunately, the standard enzymatic method of measurement for oat ß-glucan is costly and does not provide the high-throughput capability needed for plant breeding where thousands of samples are measured over a short period of time. The objective of this research was to test a micro-enzymatic approach for high-throughput phenotyping of oat ß-glucan. Fifty North American elite lines were chosen to span the range of possible values encountered in elite oat. Evaluation for both the micro-enzymatic and standard streamlined methods for correlation, repeatability, error, and bias was conducted. Pearson and Spearman correlations ranged from 0.81 to 0.86 between the two methods. Repeatability was greater for the micro-enzymatic than for the standard streamlined approach and error was similar. Although the micro-enzymatic method did contain bias as compared to the results for the standard streamlined method, this did not substantially decrease its ability to determine ß-glucan content. In addition to a substantial decrease in cost, the micro-enzymatic approach took as little as 5% of the time as compared to the streamlined method. Therefore, the micro-enzymatic method for ß-glucan evaluation is an alternative method that can enhance high-throughput phenotyping in oat breeding operations