Article

The role of enzyme amylase in two germinating seed morphs of Halopyrum mucronatum (L.) Stapf. in saline and non-saline environment

Acta Physiologiae Plantarum (Impact Factor: 1.31). 01/2011; 33(4):1185-1197. DOI:10.1007/s11738-010-0646-z

ABSTRACT The role of enzyme amylase in two germinating seed morphs, i.e. black and brown, of Halopyrum mucronatum in saline and non-saline environment was examined. Both seed morphs of this halophytic grass have variations in their moisture
content, total lipid, protein, sugar, phenol and tannin contents. Black seed exhibited higher activity compared to brown in
saline medium. Sugar mobilization in both seed morphs was also affected due to the difference in amylase activity. However,
exogenous application of GA3 in saline medium enhanced the amylase activity and sugar mobilization. Phenolic contents were similar except for vanillic
acid which was found only in brown seeds while catechol was present only in black seeds. Phenols extracted from both seed
morphs were applied to determine their effects on amylase activity. Phenolic extracts obtained from brown seeds showed higher
degree of inhibition of amylase activity. Results are discussed in relation to seed coat phenols, leaching, amylase activity
and sugar mobilization.

KeywordsAmylase–Phenols–Seed types–Leaching–Germination–Response

0 0
 · 
0 Bookmarks
 · 
192 Views
  • [show abstract] [hide abstract]
    ABSTRACT: The early morphological and physiological events occurring during maize (Zea mays cv. Nongda 108) seed imbibition and germination were studied. Water uptake of seeds exhibited a triphasic pattern with a marked increase during the initial phase of imbibition, and then a slow increase, followed by a second substantial increase. Imbibition time for 10 and 50% of seed germination was about 26 and 46 h at 30°C, respectively. The relative conductivity of maize seeds dramatically decreased during the initial phase of imbibition, followed by a substantial increase. Respiratory rate of seeds gradually increased with imbibition. Length of root cap cells decreased during the initial phase and then increased; those of meristematic zone cells increased during the initial phase and then decreased; and those of elongation zone cells and of the whole elongation zone of the radicle gradually increased during germination. The contents of soluble sugars and starch in embryos gradually decreased as the activities of α- and β-amylase strikingly increased with imbibition. In the meantime, protein contents of embryos gradually decreased and free amino acid content increased. The activities of aminopeptidase and endopeptidase increased until 12 h of imbibition and then decreased. It is concluded that germination of maize seeds is mainly completed by extension of cells in the elongation zone of the radicle, and that mobilization of stored reserves in the embryo during the initial phase of imbibition is also an early event during seed germination.
    Agricultural Sciences in China - AGRIC SCI CHINA. 01/2008; 7(8):950-957.
  • Source
    [show abstract] [hide abstract]
    ABSTRACT: J. Inst. Brew. 114(1), 27–33, 2008 Ten different barley cultivars and their corresponding malts were used to obtain different fractions. Phenolics extracted belonged to free, soluble esters and insoluble-bound fractions. Total phe-nolic content (TPC) of the free fraction, as measured according to the Folin-Ciocalteu method, ranged from 37.7 to 167.2 mg gallic acid equiv/kg of dried material (GAE/kg dw) for barley and between 34.1 and 72.3 mg GAE/kg dw for malt. The bound phenolic content ranged from 210.3 to 320.5 and between 81.1 and 234.9 mg GAE/kg dw for barley and malt, respectively. The contribution of bound phenolics to the TPC was significantly higher than that of free and esterified fractions. Catechin and ferulic acid, quantified by high performance liquid chromatog-raphy with diode array detector (HPLC-DAD), were the most abundant phenolics in the free and bound fractions, respectively. The p-coumaric acid content was lower in hulless genotypes, as compared to hulled genotypes, showing that it is mainly con-centrated in the hull. The antioxidant activities of the phenolic fractions were investigated using the radical scavenging assay (DPPH) and ferricyanide reducing power. The bound phenolics demonstrated a significantly higher antioxidant capacity com-pared to the free and esterified phenolics. During the malting process, a significant decrease of the bound phenolics was ob-served with a corresponding increase of the esterified fraction.
    01/2008; 114.
  • [show abstract] [hide abstract]
    ABSTRACT: The antiradical activity of dry beans was evaluated in order to assess the validity of this test and to correlate the results with those achieved with the Folin-Ciocalteu method and with a rapid spectrophotometric method for the analysis of total flavonoids. Four landraces (12 samples) of common beans (Phaseolus vulgaris L.), collected in two regions of Italy (Tuscany and Basilicata) in three different years, were analyzed. The EC50 values ranged from 39 to 2810 mg sample/mg 1,1-diphenyl-2-picrylhydrazil radical. The phenolic content of each sample was expressed as gallic acid equivalents; it changed from 1.17 to 4.40 mg/g. The flavonoid content, expressed as mg of (+)-catechin per g of dry seeds, ranged from 0.24 to 1.43 mg/g. The qualiquantitative composition of polyphenols has been also elucidated by means of high-performance liquid chromatography (HPLC)-diode array detection and HPLC/MS. These investigations showed that rapid tests can contribute to assessing the quality of functional food.
    Journal of Agricultural and Food Chemistry 05/2005; 53(8):3053-6. · 2.91 Impact Factor

Full-text (4 Sources)

View
64 Downloads
Available from
May 13, 2013