Hostname: page-component-586b7cd67f-r5fsc Total loading time: 0 Render date: 2024-11-24T16:38:15.606Z Has data issue: false hasContentIssue false

Endosperm cap weakening and endo-β-mannanase activity during priming of tomato (Lycopersicon esculentum cv. Moneymaker) seeds are initiated upon crossing a threshold water potential

Published online by Cambridge University Press:  19 September 2008

Peter E. Toorop*
Affiliation:
Laboratory of Plant Physiology, Wageningen Agricultural University, Arboretumlaan 4, NL-6703 BD Wageningen, Netherlands
Adriaan C. van Aelst
Affiliation:
Laboratory of Plant Cytology and Morphology, Wageningen Agricultural University, Arboretumlaan 4, NL-6703 BD Wageningen, Netherlands
Henk W. M. Hilhorst
Affiliation:
Laboratory of Plant Physiology, Wageningen Agricultural University, Arboretumlaan 4, NL-6703 BD Wageningen, Netherlands
*
* Tel: +31 317 484230 Fax: +31 317 484740[email protected]

Abstract

The relationship between endosperm cap weakening and endo-β-mannanase activity during priming and the time to germination after priming was studied in tomato (Lycopersicon esculentum) seeds. During priming of seeds in −0.4 MPa PEG, the mechanical restraint of the endosperm cap decreased while the endo-β-mannanase activity in the endosperm cap increased. There was no decrease in required puncture force and no increase in endo-β-mannanase activity in seeds during priming in −1.0 MPa PEG. Two classes of seeds could be distinguished during priming in −0.7 MPa PEG: one with decreased required puncture force and one without. A strong correlation was found between the lowering of the mechanical restraint and endo-β-mannanase activity. It was concluded that individual seeds have to cross a threshold water potential in order to develop enzyme activity and lower their mechanical restraint. A decrease in required puncture force and increase in endo-β-mannanase activity correlated with ice crystal-induced porosity in the endosperm cap cell walls in scanning micrographs. It was presumed that ice crystal-induced porosity reflects cell-wall hydrolysis. Germination time after priming correlated positively with required puncture force during priming, depending on the osmotic potential. Seeds in −1.0 MPa PEG improved their time to germination, without a decrease in the required puncture force. Therefore it was concluded that lowering of the endosperm restraint during priming positively affects the time to germination of primed seeds but is not a prerequisite for rapid germination.

Type
Physiology & Biochemistry
Copyright
Copyright © Cambridge University Press 1998

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

Alvarado, A.D., Bradford, K.J. and Hewitt, J.D. (1987) Osmotic priming of tomato seeds: effects on germination, field emergence, seedling growth, and fruit yield. Journal of the American Society for Horticultural Science 112, 427432.CrossRefGoogle Scholar
Bewley, J.D. and Black, M. (1994) Seeds. Physiology of development and germination. (2nd edition) New York, Plenum Press.CrossRefGoogle Scholar
Bino, R.J., de Vries, J.N., Kraak, H.L. and van Pijlen, J.G. (1992) Flow cytometric determination of nuclear replication stages in tomato seeds during priming and germination. Annals of Botany 69, 231236.CrossRefGoogle Scholar
Bradford, K.J. (1995) Water relations in seed germination. pp 351396in, Kigel, J., Galili, G. (Eds) Seed development and germination. New York, Marcel Dekker Inc.Google Scholar
Bradford, K.J. and Haigh, A.M. (1994) Relationship between accumulated hydrothermal time during seed priming and subsequent seed germination rates. Seed Science Research 4, 6369.CrossRefGoogle Scholar
Bray, C.M., Davison, P.A., Ashraf, M. and Taylor, R.M. (1989) Biochemical changes during osmopriming of leek seeds. Annals of Botany 63, 185193.CrossRefGoogle Scholar
Cantliffe, D.J., Fischer, J.M. and Nell, T.A. (1984) Mechanism of seed priming in circumventing thermodormancy in lettuce. Plant Physiology 75, 290294.CrossRefGoogle ScholarPubMed
Coolbear, P. and Grierson, D. (1979) Studies on the changes in the major nucleic acid components of tomato seeds (Lycopersicon esculentum Mill.) resulting from osmotic presowing treatment. Journal of Experimental Botany 30, 11531162.CrossRefGoogle Scholar
Dahal, P. and Bradford, K.J. (1990) Effects of priming and endosperm integrity on seed germination rates of tomato genotypes. II. Germination at reduced water potential. Journal of Experimental Botany 41, 14411453.CrossRefGoogle Scholar
Dahal, P., Nevins, D.J. and Bradford, K.J. (1997) Relationship of endo-β-mannanase activity and cell wall hydrolysis in tomato endosperm to germination rates. Plant Physiology 113, 12431252.CrossRefGoogle Scholar
Davison, P.A., Taylor, R.M. and Bray, C.M. (1991) Changes in ribosomal RNA integrity in leek (Allium porrum L.) seeds during osmopriming and drying-back treatments. Seed Science Research 1, 3744.CrossRefGoogle Scholar
De Castro, R.D., Zheng, X.Y., Bergervoet, J.H.W., de Vos, C.H.R. and Bino, R.J. (1995) β-Tubulin accumulation and DNA replication in imbibing tomato seeds. Plant Physiology 109, 499504.CrossRefGoogle ScholarPubMed
De Miguel, L. and Sanchez, R.A. (1992) Phytochrome-induced germination, endosperm softening and embryo growth potential in Datura ferox seeds: sensitivity to low water potential and time to escape to FR reversal. Journal of Experimental Botany 43, 969974.CrossRefGoogle Scholar
Downie, B., Hilhorst, H.W.M. and Bewley, J.D. (1994) A new assay for quantifying endo-D-mannanase activity using Congo Red dye. Phytochemistry 36, 829835.CrossRefGoogle Scholar
Groot, S.P.C. and Karssen, C.M. (1987) Gibberellins regulate seed germination in tomato by endosperm weakening: a study with gibberellin-deficient mutants. Planta 171, 525531.CrossRefGoogle ScholarPubMed
Groot, S.P.C., Kieliszewska-Rokicka, B., Vermeer, E. and Karssen, C.M. (1988) Gibberellin-induced hydrolysis of endosperm cell walls in gibberellin-deficient tomato seeds prior to radicle protrusion. Planta 174, 500504.CrossRefGoogle ScholarPubMed
Haigh, A.M. and Barlow, E.W.R. (1987) Water relations of tomato seed germination. Australian Journal of Plant Physiology 14, 485492.Google Scholar
Haigh, A.M., Barlow, E.W.R., Milthorpe, F.L. and Sinclair, P.J. (1986) Field emergence of tomato, carrot, and onion seeds primed in an aerated salt solution. Journal of the American Society for Horticultural Science 111, 660665.CrossRefGoogle Scholar
Hilhorst, H.W.M. (1995) A critical update on seed dormancy. I. Primary dormancy. Seed Science Research 5, 6173.CrossRefGoogle Scholar
Hilhorst, H.W.M. and Downie, B. (1996) Primary dormancy in tomato (Lycopersicon esculentum cv. Moneymaker): studies with the sitiens mutant. Journal of Experimental Botany 47, 8997.CrossRefGoogle Scholar
Jeffree, C.E. and Read, N.D. (1991) Ambient- and low-temperature scanning electron microscopy. pp 313413 in Hall, J.L., Hawes, C. (Eds) Electron microscopy of plant cells. London, Academic Press.CrossRefGoogle Scholar
Karssen, C.M., Haigh, A., van der Toorn, P. and Weges, R. (1989) Physiological mechanisms involved in seed priming. pp 269280 in, Taylorson, R.B. (Ed.) Recent advances in the development and germination of seeds. New York, Plenum Press.CrossRefGoogle Scholar
Lanteri, S., Saracco, F., Kraak, H.L. and Bino, R.J. (1994) The effects of priming on nuclear replication activity and germination of pepper (Capsicum annuum) and tomato (Lycopersicon esculentum) seeds. Seed Science Research 4, 8187.CrossRefGoogle Scholar
Leubner-Metzger, G., Fründt, C. and Meins, F. Jr. (1996) Effects of gibberellins, darkness and osmotica on endosperm rupture and class I β-1,3-glucanase induction in tobacco seed germination. Planta 199, 282288.CrossRefGoogle Scholar
Mauromicale, G. and Cavallaro, V. (1995) Effects of seed osmopriming on germination of tomato at different water potential. Seed Science and Technology 23, 393403.Google Scholar
Meilgaard, M., Civille, G.V. and Carr, B.T. (1987) Sensory evaluation techniques. Boca Raton, CRC Press Inc.Google Scholar
Michel, B.E. and Kaufmann, M.R. (1973) The osmotic potential of polyethylene glycol 6000. Plant Physiology 51, 914916.CrossRefGoogle ScholarPubMed
Ni, B.-R. and Bradford, K.J. (1992) Quantitative models characterising seed germination responses to abscisic acid and osmoticum. Plant Physiology 98, 10571068.CrossRefGoogle ScholarPubMed
Nonogaki, H., Matsushima, H. and Morohashi, Y. (1992) Galactomannan hydrolyzing activity develops during priming in the micropylar endosperm tip of tomato seeds. Physiologia Plantarum 85, 167172.CrossRefGoogle Scholar
Still, D.W. and Bradford, K.J. (1997) Endo-β-mannanase activity from individual tomato endosperm caps and radicle tips in relation to germination rates. Plant Physiology 113, 2129.CrossRefGoogle ScholarPubMed
Still, D.W., Dahal, P. and Bradford, K.J. (1997) A single-seed assay for endo-β-mannanase activity from tomato endosperm and radicle tissues. Plant Physiology 113, 1320.CrossRefGoogle ScholarPubMed
Toorop, P.E., Bewley, J.D. and Hilhorst, H.W.M. (1996) Endo-β-mannanase isoforms are present in the endosperm and embryo of tomato seeds, but are not essentially linked to the completion of germination. Planta 200, 153158.CrossRefGoogle Scholar