Ion exchange chromatography of water extracts was used to classify
the fructans in leaves of 40 temperate dicots
and 110 temperate grass species. Of the 150 species studied, only Poa
ampla (Merrill) contained a single β-2,6
linked fructan series. All other species grown at 10/5°C day/night
temperatures (16 h day) contained some β-1,2
linked oligofructans, even when the major fructan series was β-2,6 linked.
Leaves of P. ampla plants grown at
15/10°C day/night temperatures contained some β-1,2 linked
fructans and raffinose in addition to the dominant
β-2,6 series, but did not contain significant amounts of 1-kestose or
bifurcose (1&6-kestotetraose). Leaves of Poa
arctica R.Br. and Poa bulbosa L. contained significant amounts
of raffinose and various β-1,2 linked oligomers but
no 1-kestose. In vivo synthesis of 6-kestose in leaves of P. ampla
grown at 10/5°C proceeds in the absence of
significant amounts of either 1-kestose or bifurcose. Thus P. ampla
probably has a specific 6-SST (6-sucrose-sucrosefructosyl transferase) and
might provide a ready source of β-2,6 linked grass fructan.