1,721,116 research outputs found
Aspects of 8-[14C]Benzylaminopurine Metabolism in Phaseolus vulgaris
No full textPhaseolus vulgaris L. plants were supplied through the root with [8-14C]benzylaminopurine ([14C]BA). Collections of root, apex, and leaves were made 8 and 48 hours after labeling; ethanolic extracts of tissues were purified and subjected to thin layer chromatography on silica gel and/or cellulose powder.From [14C]BA at least two different metabolites originate, the BA riboside and ribotide. The balance among [14C]BA, the riboside, and the ribotide changed in time. The [14C]BA riboside was detected as the only labeled compound in the xylem sap collected from the stem. The biological function of BA riboside and ribotide is discussed
Levels of extractable abscisic acid in the mesocarp and seed of persisiting and abscising peach fruit
No full textDeveloping fruits of peach cv. Andross were classified as to abscission potential on the basis of fruit growth rate during stage I. Levels of inhibitors were parallel in mesocarp and seed. Extracts from fruits with a high abscission potential contained significantly lower levels of an ABA-like inhibitor than did those with low or intermediate potential. Thus ABA content appeared to be positively correlated with the rate of fruit growth and increased in concentration as the fruit approached maturity
Studies on water relations of grapevine (Vitis vinifera)
No full textOn stressed and non-stressed 3-year-old grapevines grown in 100 1 containers leaf water potential (LWP) and diffusion resistance (LR) were measured during July and August 1978.
In non limiting soil water condition a linear correlation was found between LWP and the atmosphere water potential (AWP) at any time of the day, except at 10–11 am and 4–5 pm, when the plants were in a very unsteady status. At 7–8 am and 2–3 pm the regression lines were steeper than at the other times of the day. Explanations for that are given.
In non limiting water condition LWP was also related with transpirational fluxes (TF), decreasing linearly with increasing fluxes. The stressed plants did not show any of these relationships. The stressed grapevines usually showed lower LWP even at early morning hours. With relatively high AWP the stressed vines maintained sometime LWP similar to that of non stressed plants, doubling LR and reducing dramatically TF, limiting therefore the gas exchanges. After irrigation the stressed plants recovered fairly rapidly. In fact after 90 min LWP was similar to that of non-stressed plants but LR was much higher suggesting a slow metabolic recovering.
In July and August 1979 LWP and LR measurements were made on fruiting grapevines (FG) and on defruited plants (DG). FG showed a higher TF, because of a lower LR, but maintained LWP similar to that of DG, suggesting the importance of the fruit in the plant water balance either determining a more efficient water transport or acting as a capacitance
The use of microarray μpeach 1.0 to investigate the transition from pre-climacteric to climacteric phase in peach fruit
No full textThe transition from preclimacteric to climacteric phase is a critical step during fruit development and ripening. An holistic approach to study this transition has been undertaken using the first peach microarray (μpeach 1.0) containing 4800 oligos corresponding to an equal number of genes expressed at preclimacteric and climacteric stages. Microarray hybridization indicated that 260 and 98 genes are up- and down-regulated, respectively. According to the TAIR Gene Ontology, genes have been classified into three main ontologies named cellular localization, molecular function and biological process. Considering the cellular localization the most significant up-and down-regulated gene products belong to cell wall and chloroplast. As far as cell wall is concerned major up-regulated genes encode pectinesterases and expansins, while down-regulation regards genes involved in cell wall growth and lignification. Among genes localized at chloroplast level a dramatic up-regulation of those controlling isoprenoids biosynthesis has been observed. Considering ontologies concerning molecular functions and biological process, a dramatic up-regulation has been detected for genes encoding transcription factors and enzymes involved in ethylene biosynthesis and action. Among transcription factors members of the APETALA and AUX/IAA families are the most represented, while within the family of ethylene receptors a peach new member has been described
Il controllo genetico-molecolare della maturazione e della qualità dei frutti
No full textIl completamento di progetti di sequenziamento dei genomi delle diverse specie frutticole consentirà di ampliare notevolmente le conoscenze sui processi di maturazione e sui meccanismi fisiologici e molecolari più rilevanti per la definizione della qualità dei frutti. Ciò permetterà di mettere a punto strumenti molecolari utilizzabili in programmi di miglioramento genetico assistito e di razionalizzare le tecnologie di produzione e di conservazione dei prodotti ortofrutticoli
Levels of extractable para-coumaric acid in the exomesocarp and seed of persisting and abscising peach fruit
No full textBesides ABA, another inhibitor, para-coumaric acid (PCA), was isolated in peach fruit (Prunus persica Batsch cultivar 'Andross'). The nature of this inhibitor was established by combined gas chromatography-mass spectrometry. Its level was determined spectrophotometrically and confirmed by wheat coleoptile and cress seed assay on mesocarp and seed of fruits classified as to abscission potential on the basis of their growth rate during Stage I. Levels of inhibitors were parallel in exo-mesocarp and seed. Extracts from fruit with high abscission potential contained a significantly higher amount of free PCA than did those with low or intermediate potential. The bound PCA was higher in fruit with high or intermediate abscission potential and its level seems related to the pit hardening, since the highest concentrations were found during Stage II of fruit development. © 1982
Chemical thinning: ethylene and pre treatment fruit size influence enlargement, auxin transport, and apparent sink strength of French prune and 'Andross' peach
No full textEthephon applied to peach (Prunus persica L. cv. Andross) and French prune (Prunus domestica L. cv. Agen) at fruit developmental stages sensitive to ethylene-induced abscission reduced peach enlargement and the 14C-IAA transport capacities of excised peach pedicel segments. Sensitivity to (2-chloroethyl)phosphonic acid (ethephon) was inversely related to peach size prior to treatment. Triiodobenzoic acid (TIBA) increased abscission of control and ethephon-treated prunes.
Accumulation of label by fruit tissues of ethylene pretreated prune explants following xylem transport of 14C-sugar was reduced despite the absence of competing sinks and continued availability of sugar. These results provide evidence of a direct effect of ethylene on fruit tissues
Brevi trattamenti in postraccolta con ULO e 1-MCP per il mantenimento della qualità delle pesche
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