Soluble Sugar and Starch Extraction and Quantification from Maize (Zea mays) Leaves

An easy-to-perform protocol for isolating and quantifying soluble sugars (sucrose, glucose, and fructose) and starch from maize (Zea mays) leaf tissue is described. The method has been optimized to extract non-structural carbohydrates (NSC) from frozen, finely ground tissue in a methanol:chloroform:water solution. Three rounds of tissue extraction for 30 min each at 50°C provide quantitative recovery of soluble sugars. The use of alternative extraction solvents is discussed, as well as the advantages and disadvantages of these solvents. Additionally, we provide two support protocols. The first quantifies the isolated NSC via commercially available enzymatic kits that couple the amount of each specific sugar to the production of NADPH, which is detected using equipment readily available to most laboratories. The second describes the preparation of a purification column to remove strongly charged or hydrophobic molecules from the extracted sugar solution, which is required prior to quantification with high-pressure liquid chromatography or high-performance anion-exchange chromatography. The protocols are robust and easily adapted for use in measuring NSC extracted from other plant species or tissues, making them ideal for new users. © 2016 by John Wiley & Sons, Inc.