Hostname: page-component-cd9895bd7-fscjk Total loading time: 0 Render date: 2024-12-18T10:57:44.062Z Has data issue: false hasContentIssue false
  • English
  • Français

Localization of α-amylase and its inhibitor in germinating wheat seed

Published online by Cambridge University Press:  19 September 2008

K. Kanzaki ,
C. Kawabata  and
Kaz. Noda
K. Kanzaki
Affiliation:
Research Center, Nisshin Flour Milling Co. Ltd., Saitama, 354Japan
C. Kawabata
Affiliation:
Kihara Institute for Biological Research, Yokohama City University, Yokohama, 232Japan
Kaz. Noda*
Affiliation:
Kihara Institute for Biological Research, Yokohama City University, Yokohama, 232Japan
*
* Correspondence
Get access Rights & Permissions [Opens in a new window]

Abstract

Wheat (Triticum aestivum L) seeds contain a proteinaceous α-amylase inhibitor. We estimated the amount of the inhibitor that can bind to α-amylase rather than the total amount of the inhibitor, using an ELISA method. During 48 h of imbibition, the amount of the inhibitor did not change, while α-amylase activity increased rapidly. These results suggest that α-amylase synthesized de novo does not bind to the inhibitor. To examine further the interaction between α-amylase and its inhibitor, we localized immunohistochemically both α-amylase and the inhibitor in germinating seeds. In the embryo, we observed α-amylase only in the scutellar epithelial cells at 24 h after the start of imbibition, and later in the scutellar parenchyma cells. The inhibitor, on the other hand, was present between the scutellar parenchyma cells of the embryo at 0 h and 24 h after the start of imbibition, and disappeared later. α-amylase is separated from the inhibitor in the embryo. In the endosperm, we detected α-amylase in the aleurone cells at 24 h after the start of imbibition and later in the starchy endosperm. The inhibitor was present in the aleurone cells and starchy endosperm of the dry seed. During imbibition, the inhibitor in the starchy endosperm disappeared from the area to which α-amylase was secreted. It appears that α-amylase in the starchy endosperm also does not interact with the inhibitor. The aleurone cells are the only place that α-amylase can come into contact with the inhibitor. But, early secretion of α-amylase from the aleurone cells after imbibition started, and rapid disappearance of the inhibitor in the aleurone cells suggest that the α-amylase inhibitor does not work as an effective inhibitor of the endogenous α-amylase synthesized following germination.

Keywords

Triticum aestivum L.(wheat)seedα-amylaseα-amylase inhibitor
Type
Research Papers
Information
Seed Science Research , Volume 3 , Issue 4 , December 1993 , pp. 287 - 292
Copyright
Copyright © Cambridge University Press 1993

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Barns, W.C. and Blakeney, A B (1974) Determination of cereal alpha amylase using a commercially available dyelabelled substrate Starke 26, 193–197CrossRefGoogle Scholar
Gibbons, G.C. (1980) Immunohistochemical determination of the transport pathways of α-amylase in germinating barley seeds Cereal Research Communications 8, 87–96Google Scholar
Hartl, P M., Tan-Wilson, A.L and Wilson, K A. (1986) Proteolysis of Kunitz soybean trypsin inhibitor during germination Phytochemistry 25, 23–26CrossRefGoogle Scholar
Henson, C A. and Stone, J.M. (1988) Variation in α-amylase and α-amylase inhibitor activities in barley malts Journal of Cereal Science 8, 39–46CrossRefGoogle Scholar
Hill, R.D., MacGregor, A.W., Weselake, R.J. and Daussant, J. (1987) A review of some properties of an endogenous inhibitor of cereal alpha-amylase pp. 474–482 in Mares, D J (Ed.) 4th International Symposium on Pre-harvest Sprouting in Cereals. Boulder, Colorado, USA, Westview PressGoogle Scholar
Lecommandeur, D., Lauriere, C. and Daussant, J. (1987) Alpha-amylase inibitor in barley seeds: localization and quantification. Plant Physiology and Biochemistry (Paris) 25, 711–715Google Scholar
Maeda, K. (1986) The complete amino acid sequence of the endogenous α-amylase inhibitor in wheat Biochimica et Biophysica Acta 871, 250–256CrossRefGoogle Scholar
Munck, L., Mundy, J. and Vaag, P. (1985) Characterization of enzyme inhibitors in barley and their tentative role in malting and brewing American Society of Brewing Chemists Journal 43, 35–38CrossRefGoogle Scholar
Mundy, J., Hejgaard, J. and Sevendsen, I. (1984) Characterization of a bifunctional wheat inhibitor of endogenous alpha-amylase/subtilisin FEBS Letters 167, 210–214CrossRefGoogle Scholar
Okamoto, K., Kitano, H. and Akazawa, T. (1980) Biosynthesis and excretion of hydrolases in germinating cereal seeds Plant Cell Physiology 21, 201–204Google Scholar
Robertson, M. and Hill, R.D. (1989) Accumulation of an endogenous alpha-amylase inhibitor in barley during grain development Journal of Cereal Science 9, 237–246CrossRefGoogle Scholar
Silvanovich, M.P. and Hill, R.D. (1976) Affinity chromato-graphy of cereal α-amylase Analytical Biochemistry 73, 430–433CrossRefGoogle Scholar
Somogyi, M. (1960) Modification of two methods for the assay of amylase Clinical Chemistry 6, 23–35CrossRefGoogle ScholarPubMed
Weselake, R.J., MacGregor, A W and Hill, R D (1983) An endogenous alpha-amylase inhibitor in barley kernels Plant Physiology 72, 809–812CrossRefGoogle ScholarPubMed
Weselake, R.J., McGregor, A W and Hill, R D (1985) Endogenous alpha-amylase inhibitor in various cereals Cereal Chemistry 62, 120–123Google Scholar