Fructan composition in adventitious tuberous roots of <i>Viguiera discolor</i> Baker (Asteraceae) as influenced by daylength

Isejima, Eliza Mitiko; Figueiredo-Rrieiro, R. C. L.; Zaidan, Lilian Beatriz Penteado

doi:10.1111/j.1469-8137.1991.tb01018.x

Cited by 31 publications

(29 citation statements)

References 22 publications

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“…Inulin is associated with the secondary xylem and, in minor amounts, with the medullary parenchyma of Viguiera discolor (Isejima & Figueiredo-Ribeiro 1991). In Microseris lanceolata (Incoll et al 1989) and Helianthus tuberosus (Soja et al 1989), inulin is associated with the secondary phloem.…”

Section: Discussionmentioning

confidence: 99%

Meristematic endodermis and secretory structures in adventitious roots of Richterago Kuntze (Mutisieae-Asteraceae)

Melo-de-Pinna¹,

Menezes²

2003

Rev. bras. Bot.

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-(Meristematic endodermis and secretory structures in adventitious roots of Richterago Kuntze (MutisieaeAsteraceae)). The meristematic endodermis in adventitious roots of Richterago species originates in one of the fundamental meristem cells, which undergo sucessive anticlinal and periclinal divisions to build the inner cortex. The meristematic endodermis or proendodermis remains as a meristematic layer until its differentiation into endodermis, with Casparian strip. When sieve elements differentiate, endodermic secretory canals of esquizogenous origin are present at the region adjacent to primary phloem. Articulated laticifers, with cells perforated at both terminal and transversal walls, also occur during initial phases of secondary development. Presence of inulin as reserve carbohydrate in the inner cortex and vascular tissue may be related to abiotic factors, as an adaptive strategy of these species.Key words -Asteraceae, laticifers, meristematic endodermis, Richterago, secretory canals RESUMO -(Endoderme meristemática e estruturas secretoras em raízes adventícias de Richterago Kuntze (MutisieaeAsteraceae)). Nas raízes adventícias de espécies de Richterago, a endoderme meristemática origina-se a partir de uma das células do meristema fundamental, que irá sofrer sucessivas divisões anticlinais e periclinais para formar o córtex interno, permanecendo como uma camada meristemática até sua diferenciação em endoderme com as estrias de Caspary. Quando os elementos crivados já se encontram diferenciados, canais secretores endodérmicos, de origem esquizógena, podem ser visualizados nas regiões adjacentes ao floema primário. Laticíferos articulados ocorrem na fase inicial do desenvolvimento secundário, cujas células apresentam pontoações nas paredes terminais e transversais. A presença de inulina no córtex interno e no cilindro vascular, como carboidrato de reserva, pode estar relacionada com fatores abióticos, sendo uma estratégia adaptativa das espécies.

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Section: Discussionmentioning

confidence: 99%

Meristematic endodermis and secretory structures in adventitious roots of Richterago Kuntze (Mutisieae-Asteraceae)

Melo-de-Pinna¹,

Menezes²

2003

Rev. bras. Bot.

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“…The mean molecular mass of the polymer can reach 28 kDa at the end of the growing period, being five-fold higher than inulin generally found in other Asteraceae species (Isejima et al 1991). Although the proportions of oligoand polyfructans in the tuberous roots of V. discolor changed during periods of re-growth and flowering, the total content of fructans in the underground organs remained relatively high and constant, suggesting that the activity of 1-FEH might be inhibited in those organs 1.…”

Section: Introductionmentioning

confidence: 95%

Fructan degradation and hydrolytic activity in tuberous roots of Viguiera discolor Baker (Asteraceae), a herbaceous species from the cerrado

et al. 2003

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-(Fructan degradation and hydrolytic activity in tuberous roots of Viguiera discolor Baker (Asteraceae), a herbaceous species from the cerrado). Fructans of the inulin type are the major reserve carbohydrates in tuberous roots of Viguiera discolor, a perennial herb native to the cerrado. Changes in molecular mass of the polymer, followed by releasing free fructose suggested that hydrolysis could be related to the sprouting of the buds after the dormant period, when aerial parts of the plant are naturally absent. Excision of aerial parts resulted in the increase of fructan 1-exohydrolase (1-FEH) activity in tuberous roots after sprouting. 1-FEH was partially purified from this material by binding to ConA-Sepharose and the highest activity was detected at pH 5.4 and between 20 and 40 °C. Values of K m for V. discolor inulin could not be determined since no saturation was observed up to 10%. The study of the kinetics of the 1-FEH activity showed that it does not follow MichaelisMenten and apparently presents allosteric behaviour, as data fits in the Hill equation. The 1-FEH from V. discolor is a glycoprotein, more active on low molecular mass fructans than on high molecular mass inulin from the same species.Key words -Asteraceae, cerrado, fructan 1-exohydrolase, inulin RESUMO -(Degradação de frutanos e atividade hidrolítica em raízes tuberosas de Viguiera discolor Baker, uma espécie herbácea de Asteraceae do cerrado). Frutano do tipo inulina é o principal carboidrato de reserva das raízes tuberosas de Viguiera discolor, uma espécie herbácea nativa do cerrado. Variações na massa molecular do polímero, acompanhadas de altas proporções de frutose livre sugeriram que a hidrólise do mesmo poderia estar associada à brotação das plantas, após o período de dormência, quando toda a parte aérea é naturalmente eliminada. Após indução experimental de brotação e estímulo da atividade hidrolítica, por eliminação da parte aérea, o extrato enzimático foi parcialmente purificado por adsorção em Sepharose ConA, sendo a maior atividade detectada em pH 5,4 e entre 20 e 40 °C. Não foi possível determinar os valores de K m para a inulina, uma vez que até a concentração de 10% não houve a saturação do substrato. O estudo da cinética da atividade de frutano 1-exohidrolase mostrou que a mesma não corresponde à cinética de Michaelis-Menten, apresentando um comportamento aparentemente alostérico, uma vez que os dados se enquadram na equação de Hill. A 1-FEH de V. discolor é uma glicoproteína, mais ativa sobre oligofrutanos do que sobre inulina de alta massa molecular, como a encontrada em outras Asteráceas, e principalmente na própria espécie.Palavras-chave -Asteraceae, cerrado, frutano 1-hexohidrolase, inulina

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“…According to Barta (1995), these are the most suitable inulin sources for utilization at industrial scale, as they have high productivity estimated in 4.5, 2.5 and 0.9 ton/ha, repectively. Roots of some plants of the Compositae and Asteraceae families, native in the Brazilian savannas, contain up to 86% of fructans, representing inulin source and are potentially interesting for industrial use (Isesima et al, 1991).…”

Section: Introductionmentioning

confidence: 99%

Purification and characterization of β-Fructosidase with inulinase activity from Aspergillus niger - 245

Cruz

Belote

Dorta

et al. 1998

Braz. arch. biol. technol.

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Fructan composition in adventitious tuberous roots of Viguiera discolor Baker (Asteraceae) as influenced by daylength

Cited by 31 publications

References 22 publications

Meristematic endodermis and secretory structures in adventitious roots of Richterago Kuntze (Mutisieae-Asteraceae)

Meristematic endodermis and secretory structures in adventitious roots of Richterago Kuntze (Mutisieae-Asteraceae)

Fructan degradation and hydrolytic activity in tuberous roots of Viguiera discolor Baker (Asteraceae), a herbaceous species from the cerrado

Purification and characterization of β-Fructosidase with inulinase activity from Aspergillus niger - 245

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