Analysis of Polar and Nonpolar Small Plant Growth Hormones and Quantification by LC/MS.

Plant hormones are small metabolites that regulate all aspects of plant growth and development, including plant defense. The detection and quantification of these hormones are critical to understanding the mechanism of growth regulation in plants. In maize, a wealth of genetic resources has enabled progress on elucidating the genetic mechanisms underlying plant growth. Biochemical studies of growth in maize can provide insight into the physiological mechanisms of growth control by measuring endogenous levels of plant hormones, and this knowledge would be enhanced by the development of a method to analyze several hormones in a single small sample of tissue. We provide here a simple protocol to extract and accurately quantify six classes of plant hormones in a single liquid chromatography/mass spectrometry injection run using maize tissues. Those hormones include abscisic acid (ABA), 1-aminocyclopropane-1-carboxylate (ACC), gibberellic acid (GA), 3-indoleacetic acid (IAA), jasmonic acid (JA), and salicylic acid (SA), as well as an accumulated phytoanticipin of maize, 24-dihydroxy-7-methoxy-1,4-benzoxazin-3-one (DIMBOA), which influences the levels of IAA.