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

Asega, Amanda F.; Nascimento, João Roberto Oliveira do; Carvalho, Maria Ângela Machado de

doi:10.1016/j.jplph.2010.09.002

Cited by 23 publications

(11 citation statements)

References 32 publications

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“…Free and combined fructose were measured in the two fractions by a ketose-specific modification of the anthrone reaction (Jermyn, 1956 ), using fructose as standard, while reducing sugars were measured in the fructo-oligosaccharide fraction, using glucose as standard (Somogyi, 1945 ). Carbohydrates in the oligosaccharide fraction were analyzed by HPAEC/PAD, using a 2 × 250 mm CarboPac PA-1 column on an ICS 3000 Dionex System (USA), according to Asega et al ( 2011 ). Proline was extracted from lyophilized samples (500 mg) of rhizophores and leaves with different water contents as measured in tissues along the experiment.…”

Section: Methodsmentioning

confidence: 99%

Structural and metabolic changes in rhizophores of the Cerrado species Chrysolaena obovata (Less.) Dematt. as influenced by drought and re-watering

et al. 2015

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The high fructan contents in underground organs of Cerrado species, high water solubility, and fast metabolism of these compounds highlight their role as carbon storage and as an adaptive feature in plants under drought. In this study, we showed that anatomical structure, in association with soluble compounds and metabolism of inulin-type fructans were modified in rhizophores of Crysolaena obovata submitted to water suppression and recovery after re-watering. Plants were subjected to daily watering (control), suppression of watering for 22 days (water suppression) and suppression of watering followed by re-watering after 10 days (re-watered). Plants were collected at time 0 and after 3, 7, 10, 12, 17, and 22 days of treatment. In addition to changes in fructan metabolism, high proline content was detected in drought stressed plants, contributing to osmoregulation and recovery after water status reestablishment. Under water suppression, total inulin was reduced from approx. 60 to 40%, mainly due to exohydrolase activity. Concurrently, the activity of fructosyltransferases promoted the production of short chain inulin, which could contribute to the increase in osmotic potential. After re-watering, most parameters analyzed were similar to those of control plants, indicating the resumption of regular metabolism, after water absorption. Inulin sphero-crystals accumulated in parenchymatic cells of the cortex, vascular tissues and pith were reduced under drought and accompanied anatomical changes, starting from day 10. At 22 days of drought, the cortical and vascular tissues were collapsed, and inulin sphero-crystals and inulin content were reduced. The localization of inulin sphero-crystals in vascular tissues of C. obovata, as well as the decrease of total inulin and the increase in oligo:polysaccharide ratio in water stressed plants is consistent with the role of fructans in protecting plants against drought.

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Section: Methodsmentioning

confidence: 99%

Structural and metabolic changes in rhizophores of the Cerrado species Chrysolaena obovata (Less.) Dematt. as influenced by drought and re-watering

et al. 2015

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“…On the other hand, 1‐FEH activity is increased by cold and drought, leading to accumulation of low DP fructans and sucrose (Portes et al. 2008; Asega et al. 2011; Garcia et al.…”

Section: Introductionmentioning

confidence: 99%

“…Since mild cold and drought limit growth more than photosynthesis, accumulation of sucrose occurs, which favours the activation of fructosyltransferases (Hare et al 1998;De Roover et al 2000). On the other hand, 1-FEH activity is increased by cold and drought, leading to accumulation of low DP fructans and sucrose (Portes et al 2008;Asega et al 2011;Garcia et al 2011).…”

Section: Introductionmentioning

confidence: 99%

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

et al. 2012

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Elevated [CO2 ] is suggested to mitigate the negative effects of water stress in plants; however responses vary among species. Fructans are recognised as protective compounds against drought and other stresses, as well as having a role as reserve carbohydrates. We analysed the combined effects of elevated [CO2 ] and water deficit on fructan metabolism in the Cerrado species Viguiera discolor Baker. Plants were cultivated for 18 days in open-top chambers (OTC) under ambient (∼380 ppm), and high (∼760 ppm) [CO2 ]. In each OTC, plants were submitted to three treatments: (i) daily watering (control), (ii) withholding water (WS) for 18 days and (iii) re-watering (RW) on day 11. Analyses were performed at time 0 and days 5, 8, 11, 15 and 18. High [CO2 ] increased photosynthesis in control plants and increased water use efficiency in WS plants. The decline in soil water content was more distinct in WS 760 (WS under 760 ppm), although the leaf and tuberous root water status was similar to WS 380 plants (WS under 380 ppm). Regarding fructan active enzymes, 1-SST activity decreased in WS plants in both CO2 concentrations, a result consistent with the decline in photosynthesis and, consequently, in substrate availability. Under WS and both [CO2 ] treatments, 1-FFT and 1-FEH seemed to act in combination to generate osmotically active compounds and thus overcome water deficit. The proportion of hexoses to sucrose, 1-kestose and nystose (SKN) was higher in WS plants. In WS 760, this increase was higher than in WS 380, and was not accompanied by decreases in SKN at the beginning of the treatment, as observed in WS 380 plants. These results suggest that the higher [CO2 ] in the atmosphere contributed to maintain, for a longer period, the pool of hexoses and of low DP fructans, favouring the maintenance of the water status and plant survival under drought.

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“…Higher free fructose peaks suggest intense 1-FEH activity or side 1-FFT activity transferring free fructose to water (Ende et al 1996;Roover et al 1999). Generally, 1-FEH has low activity, but it can be stimulated by defoliation, sprouting, flowering and environmental factors such as cold (Roover et al 1999;Vergauwen et al 2000;Asega & Carvalho 2004;Asega et al 2011). The field-grown plants in uncontrolled environmental conditions studied here were thus subjected to a set of factors and phenological demands that resulted in the obtained fructan profiles.…”

Section: Soluble Carbohydratesmentioning

confidence: 99%

Fructan dynamics in the underground organs of Chresta exsucca (Asteraceae), a dry season flowering species

2017

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Climatic seasonality has an infl uence on the phenology of native Cerrado plants. Herbs and subshrubs tend to fl ower in the rainy season, although some species of these habits fl ower in the dry season. Reserve carbohydrates, stored in the underground organs, are used to support phases of high energy-demand, but also may protect plants from damage during periods of environmental limitation. In this study we evaluated variation in fructan levels in the underground organs of fi eld-grown plants of Chresta exsucca among diff erent phenological phases. Chresta exsucca fl owers in the dry season and possesses a diff use underground system, which stores inulin-type fructans. Resprouting was continual during the sampling period. Oligosaccharide content was always higher than polysaccharide content, except during senescence, the only phase with an oligosaccharide: polysaccharide ratio < 1. Fructan accumulation occurred during vegetative growth until fl owering. Fructan mobilization was prominent during resprouting until the beginning of vegetative growth. Fructans stored in the underground organs of C. exsucca serve to fulfi ll the energetic demands of development and maintenance of this complex structure. In this way, fructans are essential to the persistence of this species in the environment of the Cerrado by ensuring reproduction in harsh conditions, such as drought.

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

Cited by 23 publications

References 32 publications

Structural and metabolic changes in rhizophores of the Cerrado species Chrysolaena obovata (Less.) Dematt. as influenced by drought and re-watering

Structural and metabolic changes in rhizophores of the Cerrado species Chrysolaena obovata (Less.) Dematt. as influenced by drought and re-watering

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

Fructan dynamics in the underground organs of Chresta exsucca (Asteraceae), a dry season flowering species

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

Cited by 23 publications

References 32 publications

Structural and metabolic changes in rhizophores of the Cerrado species Chrysolaena obovata (Less.) Dematt. as influenced by drought and re-watering

Structural and metabolic changes in rhizophores of the Cerrado species Chrysolaena obovata (Less.) Dematt. as influenced by drought and re-watering

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

Fructan dynamics in the underground organs of Chresta exsucca (Asteraceae), a dry season flowering species

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