Hostname: page-component-78c5997874-v9fdk Total loading time: 0 Render date: 2024-11-05T10:24:50.446Z Has data issue: false hasContentIssue false

Molecular cloning and characterization of an endo-β-mannanase gene expressed in the lettuce endosperm following radicle emergence

Published online by Cambridge University Press:  22 February 2007

Aoxue Wang
Affiliation:
Department of Botany, University of Guelph, Guelph, Ontario, N1G 2W1, Canada
Jieran Li
Affiliation:
Department of Botany, University of Guelph, Guelph, Ontario, N1G 2W1, Canada
J. Derek Bewley*
Affiliation:
Department of Botany, University of Guelph, Guelph, Ontario, N1G 2W1, Canada
*
*Correspondence, Fax: +1 519 767 1991 Email:, [email protected]

Abstract

Endo-β-mannanase (EC 3.2.1.78), an enzyme that mobilizes the endosperm cell walls of the lettuce (Lactuca sativa L.) seed, increases in activity in the micropylar and lateral regions of this tissue following the completion of germination. Its complementary DNA (cDNA) sequence (LsMan1) was determined using the polymerase chain reaction (PCR) with degenerate primers. The 3‘-end of the cDNA sequence was obtained by 3‘-end rapid amplification of cDNA ends (RACE), and the 5‘-end sequence by genome walking and 5‘-end RACE. The predicted amino acid sequence from the cDNA has a high identity with endo-β-mannanases present in other species (e.g. 67% identity with coffee β-1,4-mannan endohydrolase, 62% identity with tomato fruit endo-β-mannanase). Southern blot analysis suggests the presence of several members of an endo-β-mannanase gene family in the lettuce genome. Several isoforms of the enzyme, including three major ones, were detected by isoelectric focusing. Based on Northern blot analysis, accumulation of the endo-β-mannanase mRNA occurred only after lettuce seeds had germinated, and increased thereafter, although enzyme activity persisted after transcription declined.

Type
Research Article
Copyright
Copyright © Cambridge University Press 2004

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

Bewley, J.D. (1997) Breaking down the walls – a role for endo-β-mannanase in release from seed dormancy? Trends in Plant Science 2, 464469CrossRefGoogle Scholar
Bewley, J.D. and Halmer, P. (1980) Embryo–endosperm interactions in the hydrolysis of lettuce seed reserves. Israel Journal of Botany 29, 118132Google Scholar
Bewley, J.D., Leung, D.W.M. and Ouellette, F.B. (1983) The cooperative role of endo-β-mannanase, β-mannosidase and α-galactosidase in the mobilization of endosperm cell wall hemicelluloses of germinated lettuce seed. pp. 137152in Nozzolillo, C.;, Lea, P.J.;, Loewus, F.; (Eds) Mobilization of reserves in germination. New York, Plenum.CrossRefGoogle Scholar
Bewley, J.D., Burton, R.A., Morohashi, Y. and Fincher, G.B. (1997) Molecular cloning of a cDNA encoding a (1→4)-β-mannan endohydrolase from the seeds of germinated tomato (Lycopersicon esculentum). Planta 203, 454459CrossRefGoogle Scholar
Bourgault, R. and Bewley, J.D. (2002a) Gel diffusion assays for endo-β-mannanase and pectin methylesterase can underestimate enzyme activity due to proteolytic degradation: A remedy. Analytical Biochemistry 300, 8793CrossRefGoogle ScholarPubMed
Bourgault, R. and Bewley, J.D. (2002b) Variation in its C-terminal amino acids determines whether endo-β-mannanase is active or inactive in ripening tomato fruits of different cultivars. Plant Physiology 130, 12541262CrossRefGoogle ScholarPubMed
Cantliffe, D.J., Nascimento, W.M., Sung, Y. and Huber, D.J. (2000) Lettuce endosperm weakening: a role for endo-β-mannanase in seed germination at high temperature. pp. 277285in Black, M.;, Bradford, K.J.;, Vazquez-Ramos, J. (Eds) Seed biology: Advances and applications. Wallingford, CABI Publishing.Google Scholar
Dirk, L.M.A., Griffen, A.M., Downie, B. and Bewley, J.D. (1995) Multiple isozymes of endo-β-mannanase in dry and imbibed seeds. Phytochemistry 40, 10451056CrossRefGoogle Scholar
Dulson, J. and Bewley, J.D. (1989) Mannanase from Lactuca sativa: metabolic requirements for production and partial purification. Phytochemistry 28, 363369CrossRefGoogle Scholar
Halmer, P. (1989) De novo synthesis of mannanase by the endosperm of Lactuca sativa. Phytochemistry 28, 371378CrossRefGoogle Scholar
Halmer, P. and Bewley, J.D. (1979) Mannanase production by the lettuce endosperm – control by the embryo. Planta 144, 333340CrossRefGoogle ScholarPubMed
Halmer, P., Bewley, J.D. and Thorpe, T.A. (1975) Enzyme to break down lettuce endosperm cell wall during gibberellin- and light-induced germination. Nature 258, 716718CrossRefGoogle Scholar
Halmer, P., Bewley, J.D. and Thorpe, T.A. (1976) An enzyme to degrade lettuce endosperm cell walls. Appearance of a mannanase following phytochrome- and gibberellin-induced germination. Planta 130, 189196CrossRefGoogle ScholarPubMed
Halmer, P., Bewley, J.D. and Thorpe, T.A. (1978) Degradation of the endosperm cell walls of Lactuca sativa L. cv. Grand Rapids. Timing of mobilization of soluble sugars, lipid and phytate. Planta 139, 18CrossRefGoogle Scholar
Ikuma, H. and Thimann, K.V. (1963) The role of the seed coats in germination of photosensitive lettuce seeds. Plant and Cell Physiology 4, 169185Google Scholar
Jones, R.L. (1974) The structure of the lettuce endosperm. Planta 121, 133146CrossRefGoogle ScholarPubMed
Leung, D.W.M., Reid, J.S.G. and Bewley, J.D. (1979) Degradation of the endosperm cell walls of Lactuca sativa, cv. Grand Rapids in relation to the mobilization of proteins and the production of hydrolytic enzymes in the axis, cotyledons and endosperm. Planta 136, 335341CrossRefGoogle Scholar
Marraccini, P., Rogers, W.J., Allard, C., Andre, M-L., Caillet, V., Lacoste, N., Lausanne, F. and Michaux, S. (2001) Molecular and biochemical characterization of endo-β-mannanases from germinating coffee (Coffea arabica) grains. Planta 213, 296308CrossRefGoogle ScholarPubMed
Mo, B. and Bewley, J.D. (2002) β-Mannosidase (EC 3.2.1.25) activity during and following germination of tomato (Lycopersicon esculentum Mill.) seeds. Purification, cloning and characterization. Planta 215, 141152CrossRefGoogle ScholarPubMed
Nascimento, W.M., Cantliffe, D.J. and Huber, D.J. (2001) Endo-β-mannanase activity and seed germination of thermosensitive and thermotolerant lettuce genotypes in response to seed priming. Seed Science Research 11, 255264Google Scholar
Nijsse, J., Erbe, E., Brantjes, N.B.M., Schel, J.H.N. and Wergin, W.P. (1998) Low-temperature scanning electron microscopic observations on endosperm in imbibed and germinated lettuce seeds. Canadian Journal of Botany 76, 509516CrossRefGoogle Scholar
Nonogaki, H. and Morohashi, Y. (1996) An endo-β-mannanase develops exclusively in the micropylar endosperm of tomato seeds prior to radicle emergence. Plant Physiology 110, 555559CrossRefGoogle ScholarPubMed
Nonogaki, H. and Morohashi, Y. (1999) Temporal and spatial pattern of the development of endo-β-mannanase activity in germinating and germinated lettuce seeds. Journal of Experimental Botany 50, 13071313Google Scholar
Nonogaki, H., Gee, O.H. and Bradford, K.J. (2000) A germination-specific endo-β-mannanase gene is expressed in the micropylar endosperm cap of tomato seeds. Plant Physiology 123, 12351246CrossRefGoogle ScholarPubMed
Reid, J.S.G. and Meier, H. (1973) Enzyme activities and galactomannan mobilization in germinating seeds of fenugreek (Trigonella foenum-graecum L. Leguminosae). Secretion of α-galactosidase and β-mannosidase by the aleurone layer. Planta 112, 301308CrossRefGoogle Scholar
Sambrook, J., Fritsch, E.F. and Maniatis, T. (1989) Molecular cloning: A laboratory manual (2nd edition). Cold Spring Harbor, New York, Cold Spring Harbor Laboratory Press.Google Scholar
Wan, C.-Y. and Wilkins, T.A. (1994) A modified hot borate method significantly enhances the yields of high quality RNA from cotton (Gossypium hirsutum L.). Analytical Biochemistry 233, 712CrossRefGoogle Scholar