Am. Tronsmo et al., CARBOHYDRATE CONTENT AND GLYCOSIDASE ACTIVITIES FOLLOWING COLD HARDENING IN 2 GRASS SPECIES, Physiologia Plantarum, 88(4), 1993, pp. 689-695
The freezing resistance of the grass species Phleum pratense L. (timot
hy) and Phalaris arundinacea L. increases significantly after cold har
dening. The content and composition of soluble carbohydrates were dete
rmined in the plants after short day treatment, cold hardening and deh
ardening. The amounts of mono-, di- and trisaccharides were reduced du
ring the short day treatment, increased during cold hardening and decr
eased again during dehardening. The total amounts of soluble carbohydr
ates (mono-, di-, tri- and polysaccharides) were the same in hardened
and dehardened plants, indicating that during hardening soluble polysa
ccharides (fructose polymers, fructans) were converted to mono- and ol
igosaccharides. Sucrose increased most after hardening conditions and,
in P. arundinacea, a significant increase in 1-F-fructosylsucrose (is
okestose) was also observed. Invertase (8-fructofuranosidase, EC 3.2.1
.26) activity increased following cold hardening and decreased followi
ng dehardening, while the alpha-galactosidase (EC 3.2.1.22) activity s
eemed to increase after dehardening. The glycosidases are probably inv
olved in the mobilisation of polysaccharides during cold hardening.