Purification and properties of β‐xylosidase isozymes from cucumber seeds

Mujer, Cesar V.; Miller, Alexander

doi:10.1111/j.1399-3054.1991.tb02919.x

Cited by 7 publications

(6 citation statements)

References 27 publications

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“…In plants, b-xylosidase activity has been reported in the culture medium of sycamore cells (Tezuka et al 1993). A thermostable b-xylosidase has been isolated from sugarcane (Chinen et al 1982) and two isoenzymes of b-xylosidase have been purified from immature seeds of cucumber (Mujer and Miller 1991). b-Xylosidase activity and expression of the b-xylosidase gene were also reported during strawberry fruit ripening (Martı´nez et al 2004).…”

Section: Discussionmentioning

confidence: 97%

Expression of β-galactosidase and β-xylosidase genes during microspore and pollen development

Hrubá

Honys

Twell

et al. 2004

Planta

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Tobacco (Nicotiana tabacum L.) microspores at the time of mitosis are characterized by the abundant occurrence of 92- and 98-kDa glycoproteins (GP92 and GP98). GP92 is a soluble protein while GP98 is bound to the insoluble microspore fraction. Both glycoproteins were isolated by affinity chromatography and SDS-PAGE and analysed by MS. Peptide sequences were determined by mu-HPLC/nano-ESI-MS/MS (electrospray ionization tandem MS). GP92 displayed homology to beta-galactosidase (EC 3.2.1.23) and GP98 to beta-xylosidase (EC 3.2.1.37) from Arabidopsis thaliana (L.) Heynh. The activities of the two enzymes in microspore and pollen extracts of tobacco exhibited similar developmental changes to the occurrence of GP92 and GP98, with a maximum around microspore mitosis. These two glycoproteins are the first identified enzymes characteristic of mitotic microspores. Arabidopsis transcriptomic data for five beta-galactosidase and three beta-xylosidase genes abundantly expressed in pollen were verified by reverse transcription-PCR of RNA from different stages of Arabidopsis pollen development and from various parts of the sporophyte. The results showed abundant expression of two genes (At5g20710, At1g31740) homologous to tobacco GP92 in microspores and early pollen, and of three genes (At5g56870, At2g16730 and At4g35010) in maturing pollen. Analysis of beta-xylosidases showed abundant expression of a late pollen-specific gene At3g62710 and low expression of an early gene At5g10560. It is suggested that the early beta-galactosidase and beta-xylosidase genes may participate in cell wall loosening associated with pollen expansion after microspore mitosis and that the products of the late genes may play a role in cell expansion during pollen germination.

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Section: Discussionmentioning

confidence: 97%

Expression of β-galactosidase and β-xylosidase genes during microspore and pollen development

Hrubá

Honys

Twell

et al. 2004

Planta

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“…The main examples are listed in Table 1. Enzyme activity in vitro: Mujer & Miller (1991); Bouranis & Niavis (1992); Goujon et al Iannetta & Fry (1999); Sulová & Farkas (1999); Campbell & Braam (1999); Steele & Fry (1999; Steele et al The present article does not discuss in detail the evidence that these enzymes are located in the PCW, but this point is well established in many cases and has been reviewed (Fry, 1995). Also, the present article focuses on enzymes that appear likely to act on structural wall components rather than on low-M r solutes (e.g.…”

Section: Enzyme-catalysed Reactionsmentioning

confidence: 99%

Primary cell wall metabolism: tracking the careers of wall polymers in living plant cells

2004

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Contents Primary cell walls: composition, deposition and roles000 Reactions that have been proposed to occur in primary cell walls000 Tracking the careers of wall components in vivo: evidence for action of enzymes in the walls of living plant cells000 Evidence for the occurrence of nonenzymic polymer scission in vivo?000 Conclusion000 Summary Numerous examples have been presented of enzyme activities, assayed in vitro, that appear relevant to the synthesis of structural polysaccharides, and to their assembly and subsequent degradation in the primary cell walls (PCWs) of higher plants. The accumulation of the corresponding mRNAs, and of the (immunologically recognized) proteins, has often also (or instead) been reported. However, the presence of these mRNAs, antigens and enzymic activities has rarely been shown to correspond to enzyme action in the living plant cell. In some cases, apparent enzymic action is observed in vivo for which no enzyme activity can be detected in in‐vitro assays; the converse also occurs. Methods are reviewed by which reactions involving structural wall polysaccharides can be tracked in vivo. Special attention is given to xyloglucan endotransglucosylase (XET), one of the two enzymic activities exhibited in vitro by xyloglucan endotransglucosylase/hydrolase (XTH) proteins, because of its probable importance in the construction and restructuring of the PCW's major hemicellulose. Attention is also given to the possibility that some reactions observed in the PCW in vivo are not directly enzymic, possibly involving the action of hydroxyl radicals. It is concluded that some proposed wall enzymes, for example XTHs, do act in vivo, but that for other enzymes this is not proven.

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“…The glycosidase activities observed suggested that several enzymes likely to hydrolyse sugar linkages in cell wall polysaccharides were present in these extracts. All of the p ‐nitrophenyl glycosidase activities detected here have previously been found in cucumbers (Mujer & Miller, 1991; Meurer & Gierschner, 1992), but no estimate of the amount of activity present was reported. All p ‐nitrophenyl glycosidases detected in fresh cucumbers have also been found in ‘Bartlett’ pears (El‐Rayah‐Ahmed & Labavitch, 1980) and grapes (Takayanagi et al.…”

Section: Resultsmentioning

confidence: 69%

“…, 1989), endo‐xylanase (Mujer et al. , 1991), β‐xylosidase (Mujer & Miller, 1991), and an endo‐1,4‐β‐glucanase (Omran et al. , 1991).…”

Section: Introductionmentioning

confidence: 99%

Evaluation of enzymatic and non‐enzymatic softening in low salt cucumber fermentations

Maruvada

McFeeters

2009

Int J of Food Sci Tech

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Retention of a firm, crisp fruit texture is a major consideration for pickled vegetables including pickles made from fermented cucumbers. It is known that cucumbers soften rapidly when fermented at low salt concentrations (<0.5 M) without added calcium. This study has shown that there is non-enzymatic softening in low salt fermentations because cucumbers soften even when heated sufficiently to inactivate pectinesterase and several glycosidases that can hydrolyse glycosidic linkages that are present in cell wall polysaccharides. Though pectinesterase activity declines and these glycosidases lose activity within the first week of fermentation there is generally greater loss of cucumber tissue firmness when enzymes are not inactivated by heat. While heating cucumbers prior to fermentation reduces softening during subsequent storage, a heat treatment after 2 weeks of fermentation does not reduce softening. This result suggested that the enzymatic reactions responsible for softening occur early in the fermentation process even though the softening does not become evident until later in the storage period. Despite the evidence of an enzymatic component of tissue softening in low salt cucumbers, softening could not be associated with specific enzymes.

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Purification and properties of β‐xylosidase isozymes from cucumber seeds

Cited by 7 publications

References 27 publications

Expression of β-galactosidase and β-xylosidase genes during microspore and pollen development

Expression of β-galactosidase and β-xylosidase genes during microspore and pollen development

Primary cell wall metabolism: tracking the careers of wall polymers in living plant cells

Evaluation of enzymatic and non‐enzymatic softening in low salt cucumber fermentations

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