DisplayTitle

Aryl-Glycosidase Activities in Germinating Maize

¹Institute of Chemistry, Slovak Academy of Sciences, Bratislava, Slovak Republic. ²Fermentation Biotechnology Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service, USDA, Peoria, IL 61604. Names are necessary to report factually on available data; however, the USDA neither guarantees nor warrants the standard of the product, and the use of the name by the USDA implies no approval of the product to the exclusion of others that may also be suitable. ³Current address: Wyatt Technology Corp., Santa Barbara, CA 93117. ⁴Corresponding author. Phone: 309-681-6377. Fax: 309-681-6427. E-mail: leathetd@ncaur.usda.gov. ⁵Office of International Programs, Agricultural Research Service, USDA, Beltsville, MD 20705.

Soluble protein extracts of germinating maize seedlings exhibited a limited ability to hydrolyze purified xylans, and specific assays were unable to confirm the presence of endo-β-1,4-xylanase activity. However, extracts contained a variety of aryl-glycosidase activities, including β-glucosidase, β-xylosidase, and α-L-arabinofuranosidase. These activities peaked in three- to four-day seedlings and were particularly concentrated in shoot and root tissues. Maximal levels of β-glucosidase were two orders of magnitude greater than those of β-xylosidase or α-L-arabinofuranosidase. Isoelectric focusing gels revealed multiple forms of these enzymes. The principal β-glucosidase and α-L-arabinofuranosidase protein species were clustered at pI 4.8–4.9 and pI 5.8–6.0, respectively. β-Xylosidase activity appeared to be associated with both of these enzymes, and no evidence was obtained for a distinct β-xylosidase.