Site of Origin and Extent of Activity of Amylases in Maize Germination

Dure, Leon S.

doi:10.1104/pp.35.6.925

Cited by 98 publications

(33 citation statements)

References 16 publications

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“…The specifi c activity of α-amylases was determined using starch as a substrate (Muentz, 1977). The activity of β-amylases was assayed following Bernfeld (1951) and Dure (1960). Pyrocatechol (0.01 M in 0.1 M phosphate buffer, pH 6.0) was used for measuring the activity of PPO (Van Lelyveld and Pretorius, 1973), whereas hydrogen peroxide (0.2 M) was used for measuring the activity of POX (Batish et al, 2006).…”

Section: Assays Of Enzyme Activitiesmentioning

confidence: 99%

Cell Phone Radiations Affect Early Growth of Vigna radiata (Mung Bean) through Biochemical Alterations

Sharma

Singh

Batish

et al. 2010

Zeitschrift Für Naturforschung C

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The indiscriminate use of wireless technologies, particularly of cell phones, has increased the health risks among living organisms including plants. We investigated the impact of cell phone electromagentic fi eld (EMF) radiations (power density, 8.55 μW cm -2 ) on germination, early growth, proteins and carbohydrate contents, and activities of some enzymes in Vigna radiata. Cell phone EMF radiations signifi cantly reduced the seedling length and dry weight of V. radiata after exposure for 0.5, 1, 2, and 4 h. Furthermore, the contents of proteins and carbohydrates were reduced in EMF-exposed plants. However, the activities of proteases, α-amylases, β-amylases, polyphenol oxidases, and peroxidases were enhanced in EMF-exposed radicles indicating their role in providing protection against EMF-induced stress. The study concludes that cell phone EMFs impair early growth of V. radiata seedlings by inducing biochemical changes.

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Section: Assays Of Enzyme Activitiesmentioning

confidence: 99%

Cell Phone Radiations Affect Early Growth of Vigna radiata (Mung Bean) through Biochemical Alterations

Sharma

Singh

Batish

et al. 2010

Zeitschrift Für Naturforschung C

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“…It is well established that in barley caryopsis both the scutellum and the aleurone layer are involved in the production and mediation of hydrolytic enzymes during germination (4,5,9,10,16,20,25).…”

Section: Introductionmentioning

confidence: 99%

“…A variety of experimental techniques have been utilised in attempts to elucidate the relative contributions of both tissues: dissection followed by incubation in the presence of either plant hormones (7,18,19) or an ,endospermlike~ substrate (10); inflicting lesions to the one tissue and thereafter measuring the contribution of the other (2); simple histochemical observation of thin sections (5,16,20,25).…”

Section: Introductionmentioning

confidence: 99%

On the relative role of the scutellum and aleurone in the production of hydrolases during germination of barley

Gibbons

1981

Carlsberg Res. Commun.

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The relative roles of the scutellum and the aleurone layer in the production and mediation of both germination-specific a-amylase and cell wall breakdown hydrolases has been examined in vivo following treatment of barley seeds with the plant hormones gibberellic acid and abscisic acid. To facilitate entry of these exogenous hormones, a technique is presented where multiple incisions b~nicks~0 are made in the outer layers of the seed prior to germination. Treatment of seeds with gibberellic acid and abscisic acid effected major changes on the pattern of hydrolase transport. The nature of the changes were such that it is concluded that the scutellum alone is capable of producing and mediating up to 50To of germination specific hydrolases in a commercial European malting barley, germinating at the conventional European malting temperature of 15 ~

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“…In 1960, Dure (6) reported that in germinating maize seeds, the site of a-amylase (EC 3.2.1.1) biosynthesis was restricted to the scutellum, whereas /3-amylase (EC 3.2.1.2) was localized in the endosperm. The crucial role of embryonic tissues (including the scutellum) in the digestion of starch of germinating cereal seeds has been proposed by several investigators.…”

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confidence: 99%

Enzymic Mechanisms of Starch Breakdown in Germinating Rice Seeds

Okamoto¹,

Akazawa²

1979

Plant Physiol.

109

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The time sequence analysis of the starch digestion pattern of the thin sectioned germinating rice (Oryza satva L.) seed specimens using the starch film method showed that at the initial stage amylase activity was almost exclusively localized in the epithelium septum between the scutelium and endosperm. Starch breakdown in the endosperm tissues began afterward; amylase activity in the aleurone layers was detectable only after 2 days. Polyacrylamide gel electrofocusing (pH 4 to 6) revealed nearly the same zymogram patterns between endosperm and scutellum extracts, although additional amylase bands appeared in the endosperm extracts at later gennination stages (4 to 6 days). These are presumably attributable to the newly synthesized enzyme molecules in the aleurone cells.Germination of starchy cereal seeds is of classical interest in plant biological research. Despite extensive investigations in a variety of disciplines (e.g. anatomical, physiological, biochemical, and enzymic), the precise nature of starch breakdown is not entirely clear. Although there is a good possibility that each specific cereal seed has its characteristic machinery for hydrolyzing reserve materials, so far no unified mechanism has been presented in different kinds of cereal seeds relating to the enzymic hydrolysis of reserve starch.Based on histological observations of germinating barley seeds, Brown and Morris (3) reported in 1890 that the site of synthesis of diastatic enzyme is in the epithelium of the scutellum; since then this unique feature of the epithelium has received much attention by several investigators (17,23). In 1960, Dure (6) reported that in germinating maize seeds, the site of a-amylase (EC 3.2.1.1) biosynthesis was restricted to the scutellum, whereas /3-amylase (EC 3.2.1.2) was localized in the endosperm. The crucial role of embryonic tissues (including the scutellum) in the digestion of starch of germinating cereal seeds has been proposed by several investigators. Briggs (2) reported that in malt, the aamylase activity located in the embryo occupied about 7% of the total activity of the seed, and that 6.5% of the endospermic aamylase was of embryonic origin. The (9,14,19,20). The important role of aleurone layers in the enzymic starch digestion revealed by such studies appears to be consistent with the classical report of Linderstr0m-Lang and Engel (13), dealing with the ultramicroscopic examination of amylase localization in malt. The over-all picture is not necessarily consistent with the above described pattern of starch digestion initiating at the embryonic tissues, studied by previous workers. In work reported in this communication, we attempted to reexamine, employing a starch film technique, the initial site of amylase formation in germinating rice seeds. MATERIALS AND METHODSGrowth of Plants and Preparation of Crude Enzyme. Rice seeds (Oryza sativa L. cv. Kimmaze) germinated in a dark chamber at 30 C were harvested at the appropriate stage (15), scutellum and endosperm tissues dissected from the see...

show abstract

Site of Origin and Extent of Activity of Amylases in Maize Germination

Cited by 98 publications

References 16 publications

Cell Phone Radiations Affect Early Growth of Vigna radiata (Mung Bean) through Biochemical Alterations

Cell Phone Radiations Affect Early Growth of Vigna radiata (Mung Bean) through Biochemical Alterations

On the relative role of the scutellum and aleurone in the production of hydrolases during germination of barley

Enzymic Mechanisms of Starch Breakdown in Germinating Rice Seeds

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