Location: Grain Quality and Structure ResearchTitle: Modulation of kernel storage proteins in grain sorghum (Sorghum bicolor (L.) Moench)) Author
|Tilley, Michael - Mike|
Submitted to: Plant Biotechnology Journal
Publication Type: Peer reviewed journal
Publication Acceptance Date: 12/20/2011
Publication Date: 6/1/2012
Citation: Kumar, T., Dweikat, I., Sato, S., Ge, Z., Neresian, N., Chen, H., Elthon, T., Bean, S., Ioerger, B.P., Tilley, M. and Clemente, T. 2012. Modulation of kernel storage proteins in grain sorghum (Sorghum bicolor (L.) Moench). Plant Biotechnology Journal. 10(5):533-544. Interpretive Summary: Grain sorghum (Sorghum bicolor (L.) Moench) ranks fifth among the cereals world-wide with respect to its importance for food and feed applications. However, sorghum is known to have lower protein digestibility than other cereals such as wheat and corn. To address this issue, transgenic sorghum was developed that expressed a hybrid wheat protein along with lines that down regulated the gamma and alpha kafirins. Experimental sorghum lines were found to have altered protein body structure and digestibility. Such lines could have an impact on the utilization of sorghum in feed and bio-fuel applications.
Technical Abstract: Grain sorghum (Sorghum bicolor (L.) Moench) ranks fifth among the cereals world-wide with respect to its importance for food and feed applications. The grain is approximately 13% protein, of which the kafirins comprise over 80% of the protein component of the grain endosperm. The kafirins are categorized into subgroups alpha, beta, and gamma.'The kafirins are co-translationally translocated to the endoplasmic reticulum (ER) where they are assembled into discrete protein bodies that tend to be poorly digestible with low functionality in food and feed applications. As a means to address the the issues surrounding functionality and digestibility in sorghum we employed a biotechnology approach that is designed to alter protein body structure, with the concomitant synthesis of a co-protein in the endosperm fraction of the grain. To this end, we report here on the molecular and phenotypic characterizations of transgenic sorghum events that are down-regulated in gamma- and the 24 kDa alpha-kafirins, and the expression of a Dy 10/Dx 5 hybrid high molecular weight glutenin protein from wheat.