| α-galactosidase (α-gal, EC 3.2.1.22) is a kind of exoglycosidase that can specifically catalyze the hydrolysis
of α- galactoside bonds. It has the ability to hydrolyze the α-1, 6-galactoside bonds involved in galacto-oligosaccharides
such as melibiose, raffinose, and stachyose, galactomannans, galactolipids and glycoproteins. It has widely been found in
animals, plants and microorganisms (archaea, bacteria, fungi) and etc. As its catalytic specificity , α-Gal has been widely
used in such fields as food, feed, agriculture, medicine and light industry, and it is considered as one of the most promising
enzyme preparations. α-Gal from different species and families exhibit great differences in sequence homology, advanced
catalytic structure, catalytic active site, enzyme-substrate binding mechanism, and thermal stability etc., which greatly limits the development and application of α-Gal. Compared with studies on α-Gal in microorganisms, studies on α-Gal in plants are
still relatively limited. In plants, α-Gal is widely involved in important physiological processes such as leaf development and
senescence, seed development and germination, fruit softening and ripening and stress response. However, the physiological and
molecular mechanisms of α-Gal involved in these processes mentioned above have still been unclear. Therefore, based on the
previous researches and reports on α-Gal, the origin, distribution, classification, catalytic property and applications, GH protein
family evolution of α-Gal and its biological functions on the biosynthesis, transport, unloading and catabolism of RFO, seed
development, dehydration tolerance and germination, response to high and/or low temperature, salt and other abiotic stresses,
and cell wall remodeling in plants are mainly reviewed in this paper. |
