A bifunctional beta-xylosidase/alpha-L-arabinosidase, exo-enzyme that acts synergistically with endohydrolases. Releases xylose and arabinose from cell walls. Does not cleave xylan from oat spelts although xylan from oat spelts was degraded to xylose when this enzyme was used in combination with xylanase. Also releases xylose and arabinose from aryl glycosides, xylo-oligosaccharides, arabinan from sugar beet and arabino-oligosaccharides, arabinan from sugar beet and arabinoxylan from wheat. Hydrolysis of (1->4)-beta-D-xylans, to remove successive D-xylose residues from the non-reducing termini. Hydrolysis of terminal non-reducing alpha-L-arabinofuranoside residues in alpha-L-arabinosides. Proteolytically cleaved in roots to form a 65 kDa protein. Belongs to the glycoside hydrolase 3 family.