Fructans and water suppression on intact and fragmented rhizophores of Vernonia herbacea

Abstract

In order to evaluate the involvement of fructans in drought tolerance

Comparison of the water-soluble carbohydrate composition and fructan structures of Agave tequilana plants of different ages

“…Thus our results are in agreement with this previous behaviour observed. The polymerisation and depolymerisation of fructans is a phenomena observed in most of the fructan accumulating plants and is associated in most of the cases to regulation of water imbalances, adaptation to cold weather or to accumulation of reserve carbohydrate and post utilisation as an energy source for flowering or re-growth (Dias-Tagliacozzo et al, 2004;Monti et al, 2005;Orthen & Wehrmeyer, 2004;Saengthongpinit & Sajjaanantakul, 2005;Shiomi et al, 2005;Tolsma, Read, & Tolhurst, 2007;Vijn & Smeekens, 1999;Wilson et al, 2004). Therefore, probably the behaviour observed of fructans distribution of A. tequilana plants from 2 to 6½ was due to a fructan accumulation process, which is a required step for agave plants before flowering.…”

Effects of elevated CO2 concentration and water deficit on fructan metabolism in Viguiera discolor Baker

“…2007 and references therein). Studies with Vernonia herbacea , one such species, showed that over long periods with low water availability, the rhizophores have high water retention, possibly related to fructan osmoregulation ability, since water retention was accompanied by changes in fructan composition (Dias‐Tagliacozzo et al. 2004), including increases in the ratio fructo‐oligosaccharides to fructo‐polysaccharides and changes in fructan active enzymes (Garcia et al.…”

“…The wide occurrence of Cerrado species with a high fructan content in underground reserve organs reinforces the role of fructans in drought stress tolerance, as these plants undergo periods of water deficit throughout their phenological cycle (Carvalho et al 2007 and references therein). Studies with Vernonia herbacea, one such species, showed that over long periods with low water availability, the rhizophores have high water retention, possibly related to fructan osmoregulation ability, since water retention was accompanied by changes in fructan composition (Dias-Tagliacozzo et al 2004), including increases in the ratio fructo-oligosaccharides to fructo-polysaccharides and changes in fructan active enzymes (Garcia et al 2011).…”

Increased expression of fructan 1-exohydrolase in rhizophores of Vernonia herbacea during sprouting and exposure to low temperature

“…Fructans have also been shown to protect membranes under stress conditions (Hincha et al, 2007). Fructan mobilization occurs when energy supply is needed ( Van den Ende et al, 2001;Asega and Carvalho, 2004) and/or to increase oligosaccharide contents under stress conditions (DiasTagliacozzo et al, 1999;Van Laere and Van den Ende, 2002;Dias-Tagliacozzo et al, 2004). Inulin hydrolysis to free fructose and sucrose occurs by the action of fructan 1-exohydrolase (1-FEH, E.C.…”