Quantification of L-Citrulline and other physiologic amino acids in watermelon and selected cucurbits

Authors: Fish, Wayne; Bruton, Benny

Submitted to: Cucurbitacea
Publication Type: Proceedings
Publication Acceptance Date: 5/12/2010
Publication Date: 11/14/2010
Citation: Fish, W.W., Bruton, B.D. 2010. Quantification of L-Citrulline and other physiologic amino acids in watermelon and selected cucurbits. In: Cucurbitaceae 2010 Proceedings, November 14-18, 2010, Charleston, South Carolina. p. 152-154.

Interpretive Summary: A quantitative method was developed for measuring free amino acids, including citrulline, in cucurbit tissues. The method can be used by research scientists and plant breeders to evaluate the effects of - and the interplay between growing conditions and a plant's genetic potential for expression of specific amino acids in it fruit.

Technical Abstract: High performance liquid chromatography of dabsyl derivatives of amino acids was employed for quantification of physiologic amino acids in cucurbits. This method is particularly useful because the dabsyl derivatives of glutamine and citrulline are sufficiently separated to allow quantification of each. Water extraction of ground frozen-thawed tissues effected complete recovery of the physiologic amino acids as demonstrated by spiking experiments and tissue combination experiments. Physiologic amino levels were determined for cantaloupe, cucumber, straight-necked yellow squash, Botswana wild watermelon, and domestic watermelon. Comparison of L-citrulline levels in watermelon from different years, different cropping regions, or different stages of fruit maturity demonstrated that each of these parameters exert a marked influence on the citrulline content in a watermelon.