Fructan metabolising enzymes in rhizophores of Vernonia herbacea upon excision of aerial organs

Asega, Amanda F.; Carvalho, Maria Ângela Machado de

doi:10.1016/j.plaphy.2004.02.005

Cited by 46 publications

(51 citation statements)

References 31 publications

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“…It was also reported that a degrading activity of 1 kestose which showed patterns closely reflecting 1 FEH activity, was independent of temperatures under which onion bulbs were kept during six months. Similar variation of 1 FEH activity in rhizophores of Vermonia herbacea was noted by Asega and Carvalho, 37) although this plant is biologically different from onion. Thus, the general pat- tern of enzyme activities during the post harvest life of bulbs was characterized by a peak where hydrolyzing activities are about three fold higher, as shown in Fig.…”

Section: )supporting

confidence: 78%

“…However, it is well established that the duration of dormancy varies among growing years and among cultivars, and depends on atmospheric and environmental conditions. 26,37,45,46) Thus, during storage of onion bulbs, as other plant tissues, FOS are hydrolyzed to low DP FOS, then disaccharides, and finally to monosaccharides. This hydrolysis usually takes place early in the first weeks following harvesting with little further change during the first few weeks of dormancy.…”

Section: Catabolism Fos In Onion Bulb Tissuesmentioning

confidence: 99%

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The Metabolism of the Fructooligosaccharides in Onion Bulbs: A Comprehensive Review

2005

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In the past two decades, there has been vast expansion in the research of fructooligosaccharides (FOS), including their chemistry, biochemistry and enzymology in higher plants. However, in spite of these considerable advances in fructan science, many other aspects of the mechanisms of fructan metabolism have not been fully understood. The bulbing and yield of dry onion cultivars vary, but they depend on the contents of the high dry matter and non-structural carbohydrates (fructooligosaccharides) which contribute to keepability. The knowledge of the mechanisms of the synthesis and the degradation of the FOS occurring during growth and storage are of great interest. Important progress has been made in the research area of onion FOS, and in addition to their role as accessible reserve carbohydrates in bulbs during sprouting, FOS participate in many physiological processes of production, protection and preservation of the bulbs. This review aims to contribute to a better understanding of the metabolism of FOS in onion bulbs, based on recent investigations. The activities of the main enzymes involved in the synthesis and the hydrolysis of the FOS during the pre-harvest (growth) and post-harvest (storage) life of the bulbs are reviewed, although present knowledge is too limited to explain clearly the mechanisms triggering the enzymes activities or the mechanisms by which FOS contribute to quality and long keepability of the bulbs.

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Section: )supporting

confidence: 78%

Section: Catabolism Fos In Onion Bulb Tissuesmentioning

confidence: 99%

The Metabolism of the Fructooligosaccharides in Onion Bulbs: A Comprehensive Review

2005

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“…In fact, an increase in FEH activity was demonstrated in V. herbacea by Asega and Carvalho (2004) during the growth of induced new shoots. In September we also observed an increase in reducing sugars (figure 5), probably representing the free fructose released during fructan mobilization.…”

Section: Discussionmentioning

confidence: 96%

“…The crude extract from rhizophores was submitted to ethanol precipitation and fructo-oligosaccharide (considered here as molecules with DP ≤ 20) and fructopolysaccharide fractions were separated by centrifugation (Asega and Carvalho, 2004). Free and combined fructose were measured in the two fractions and in the crude extracts from stems and leaves by a ketose-specific modification of the anthrone reaction (Jermyn, 1956), using inulin from Helianthus tuberosus as standard.…”

Section: Extraction and Analysis Of Soluble Carbohydratesmentioning

confidence: 99%

Growth, photosynthate partitioning and fructan accumulation in plants of Vernonia herbacea (Vell.) Rusby under two nitrogen levels

Cuzzuol

Carvalho

Zaidan

2005

Braz. J. Plant Physiol.

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The effect of two nitrogen concentrations on fructan accumulation and plant growth was analysed in plants of Vernonia herbacea during a year period. Plants of this species accumulate inulin-type fructans in the underground reserve organs (rhizophores). The plants were cultivated in glasshouse conditions and received weekly nutrient solutions containing 1.3 mmol.L -1 NO 3 -(Nlimited) or 10.7 mmol.L -1 NO 3 -(N-sufficient). Plants treated with N-sufficient solution presented an increase in total growth with higher biomass, more but smaller leaves resulting in higher total leaf area, higher net assimilation rate, specific leaf mass and higher biomass allocation to aerial organs. In addition, these plants presented higher contents of reducing sugars and lower fructan contents. In contrast, N-limited plants showed reduced total growth with lower biomass, higher biomass allocation to underground organs and higher fructan contents. Therefore, although N-limited plants presented a higher fructan concentration, the amount of fructan produced per plant was similar in both N treatments. Key words: Asteraceae, cerrado, fructans, underground reserve organs.Crescimento, partição de fotossintatos e acúmulo de frutanos em plantas de Vernonia herbacea (Vell.) Rusby tratadas com dois níveis de nitrogênio. O efeito de duas concentrações de nitrogênio sobre o acúmulo de frutanos e seu crescimento foi analisado durante um ano em plantas de Vernonia herbacea. As plantas foram cultivadas em casa de vegetação e receberam semanalmente solução nutritiva contendo 1,3 mmol.L -1 NO 3 -(N-limitado) ou 10,7 mmol.L -1 NO 3 -(N-suficiente). As plantas tratadas com a solução N-suficiente apresentaram maior crescimento, com maior biomassa, número maior de folhas, porém com menor área, resultando em área foliar total mais elevada, taxa de assimilação líquida e massa foliar específica mais altas, maior alocação de biomassa para os órgãos aéreos. Além disso, revelaram teores mais altos de açúcares redutores e mais baixos de frutanos. Já as plantas que receberam solução N-limitada apresentaram menor crescimento com menor biomassa, maior alocação de biomassa para os órgãos subterrâneos e maior conteúdo de frutanos. Portanto, embora as plantas sob Nlimitado tenham apresentado maior concentração de frutanos, sua produção por planta foi semelhante nos dois tratamentos de nitrogênio. Palavras-chave: Asteraceae, cerrado, frutanos, órgãos subterrâneos de reserva.

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“…Fructans have been found in thickened underground systems of Vernonia and of other Asteraceae species from the Brazilian Cerrado (Figueiredo-Ribeiro et al, 1986;Tertuliano and Figueiredo-Ribeiro, 1993;Asega and Carvalho, 2004). These carbohydrates are generally found in plants from temperate regions and then it states that fructans are related to drought tolerance (Vijn and Smeekens, 1999) and low temperature (Hendry, 1987;Vijn and Smeekens, 1999).…”

Section: Discussionmentioning

confidence: 99%

Anatomy of the underground system in Vernonia grandiflora Less. and V. brevifolia Less. (Asteraceae)

Hayashi

Appezzato‐da‐Glória

2007

Braz. arch. biol. technol.

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Fructan metabolising enzymes in rhizophores of Vernonia herbacea upon excision of aerial organs

Cited by 46 publications

References 31 publications

The Metabolism of the Fructooligosaccharides in Onion Bulbs: A Comprehensive Review

The Metabolism of the Fructooligosaccharides in Onion Bulbs: A Comprehensive Review

Growth, photosynthate partitioning and fructan accumulation in plants of Vernonia herbacea (Vell.) Rusby under two nitrogen levels

Anatomy of the underground system in Vernonia grandiflora Less. and V. brevifolia Less. (Asteraceae)

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