The Cerrado biome covers a large area of central Brazil, containing a mosaic of physiognomies determined by soil fertility, seasonal rainfall, and fire. The ground layer vegetation presents a high eudicot diversity and a high proportion of belowground phytomass, represented mainly by a diversity of underground organs storing carbohydrates. Fructans and other soluble carbohydrates are claimed to be more than reserves, conferring protection against abiotic stresses due to osmoregulation properties and rapid turnover. Inulin- and levan-type fructans are prominent and found respectively in the underground organs of Asteraceae and Amaranthaceae, abundant families in the herbaceous Cerrado flora. Poaceae, mainly Panicoideae, is also abundant and accumulates glucose, sucrose, and malto-oligosaccharides, but not fructans, in contrast with temperate grasses. Here, we review evidence that fructans in the herbaceous flora of the Cerrado play a significant role in tolerance to drought and fire, promoting the rapid recovery of the ground-layer vegetation after environmental disturbances.

South America has a great diversity in some tribes of the Iridaceae family. Most of the Iridaceae are geophytes, with underground organs bearing buds and reserve compounds, which favor their occurrence in seasonal environments, such as the Cerrado. Non-structural carbohydrates (NSC) are the main reserves in geophytes, essential to support phenological events, and protect plants against abiotic stresses. NSC may also reflect taxonomic relationships among plant groups. The objective of this study was to determine the contents and composition of NSC in underground organs of five Iridaceae species from the Cerrado (Cipura paludosa, Cipura xanthomelas, Trimezia cathartica, Trimezia juncifolia and Sisyrinchium vaginatum), representing the tribes Tigridieae, Trimezieae and Sisyrinchieae. Soluble carbohydrates and total fructose in oligo and polysaccharide fractions, and the starch contents were determined, and sugar composition was analyzed by HPAEC-PAD. The species from the tribes Trimezieae and Tigridieae showed similar NSC profiles, with considerable accumulation of starch and glucose, fructose, sucrose and maltose. Additionally, T. juncifolia also presented raffinose and 1-kestose. In contrast, S. vaginatum of the Sisyrinchieae has very low starch content and a distinct carbohydrate profile, predominating soluble carbohydrates, possibly of the raffinose family