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Effect of low water potential on phytochrome-induced germination, endosperm softening and cell-wall mannan degradation in Datura ferox seeds

  • Rodolfo A. Sánchez (a1), Lucila de Miguel (a1), Carlos Lima (a2) and Rosa M. de Lederkremer (a2)

Abstract

Phytochrome-induced softening of the micropylar endosperm of Datura ferox seeds is followed by radicle protrusion and preceded by a significant increase in the extractable activity of β-mannanase and β-mannosidase (6 and 3 times over the far-red light controls, respectively) and a decrease in the mannan content of the micropylar endosperm cell walls. This relationship between phytochrome-induced germination, endosperm softening and mannan degradation was studied in Datura ferox seeds subjected to a range of water potentials during the presence of Pfr. Low water potential inhibited the decrease in mannose-rich cell-wall insoluble polysaccharides, the increase in activity of β-mannosidase and endosperm softening. A good correlation was found between activity of β-mannosidase measured at 45 h after exposure to a red light pulse and germination counted 24 h later when, with different external water potentials, germination varied between 0 and 90%. In contrast, no inhibitory effect of low water potential on in vitro β-mannanase activity was detected. We suggest that the in vivo action of β-mannanase might be limited by accumulation of manno-oligosaccharides caused by inhibition of β-mannosidase. These data are consistent with the concept of a link between mannan mobilization and endosperm softening. Part of the effect of low water potential on Pfr-induced germination may be mediated by inhibition of β-mannosidase activity, with consequences for mannan hydrolysis and endosperm softening.

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*Correspondence Fax: 54–011–4514–8730 Email: sanchez@ifeva.edu.ar

References

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Bewley, J. D. (1997) Seed germination and dormancy. Plant Cell 9, 10551066.
Bewley, J.D. and Black, M. (1982) Physiology and biochemistry of seeds in relation to germination, Vol. 2. Viability, dormancy and environmental control. Berlin, Springer-Verlag.
Bradford, K. J. (1995) Water relations in seed germination. pp 351359. in Kigel, J. and Galili, G., (Eds). Seed development and germination. New York, Marcel Dekker.
Bradford, K.J., Chen, F., Cooley, M.B., Dahal, P., Downie, B., Fukunaga, K.K., Gee, O.H., Gurusinghe, S., Mella, R.A., Nonogaki, H., Wu, C.-T. and Yim, K.-O. (2000) Gene expression prior to radicle emergence in imbibed tomato seeds. pp 231251. Black, M., Bradford, K.J. and Vazquez-Ramos, J., (Eds). Seed biology: advances and applications. Wallingford, UK, CABI Publishing.
Chen, F. and Bradford, K.J. (2000) Expression of an expansin is associated with endosperm weakening during tomato seed germination. Plant Physiology 124, 12651274.
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.
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.
de Miguel, L. and Sánchez, 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.
de Miguel, L., Burgin, M.J., Casal, J.J. and Sánchez, R.A. (2000) Antagonistic action of low-fluence and high-irradiation modes of response of phytochrome on germination and β-mannanase activity in Datura ferox seeds. Journal of Experimental Botany 51, 11271133.
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.
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.
Leviatov, S., Shoseyov, O. and Wolf, S. (1995) Involvement of endomannanase in the control of tomato seed germination under low temperature conditions. Annals of Botany 76, 16.
Mella, R.A., Burgin, M.J., Stanelloni, R.J. and Sánchez, R.A. (2000) Expansin gene expression is regulated by phytochrome during dormancy breakage in Datura ferox seeds.Plant Biology 2000: Abstracts of the annual meeting of the American Society of Plant Physiologists, July 2000, San Diego, CA. CA, Astract 152.
Nomaguchi, M., Nonogaki, H. and Morohashi, Y. (1995) Development of galactomannan-hydrolyzing activity in the micropylar endosperm tip of tomato seed prior to germination. Physiologia Plantarum 94, 105109.
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, 12351245.
Ouellette, B.F.F. and Bewley, J.D. (1986) β-mannoside mannohydrolase and the mobilization of the endosperm cell wall of lettuce seeds. Planta 169, 333338.
Sánchez, R.A. and de Miguel, L. (1997) Phytochrome promotion of mannan-degrading enzyme activities in the micropylar endosperm of Datura ferox seeds requires the presence of the embryo and gibberellin synthesis. Seed Science Research 7, 2733.
Sánchez, R.A., de Miguel, L. and Mercuri, O. (1986) Phytochrome control of cellulase activity in Datura ferox L. seeds and its relationship with germination. Journal of Experimental Botany 37, 15741580.
Sánchez, R.A., Sunnell, L.A., Labavitch, J.M. and Bonner, B.A. (1987) Changes in the micropylar region of the endosperm before radicle protrusion in the seeds of two Datura species. Plant Physiology 83. S-118 (abstract 711).
Sánchez, R.A., Sunnell, L.A., Labavitch, J.M. and Bonner, B.A. (1990) Changes in endosperm cell walls of two Datura species before radicle protrusion. Plant Physiology 93, 8997.
Schopfer, P. and Plachy, C. (1985) Control of seed germination by abscisic acid III. Effect on embryo growth potential (minimum turgor pressure) and growth coefficient (cell wall extensibility) in Brassica napus L. Plant Physiology 77, 676686.
Soriano, A., Sánchez, R.A. and Eilberg, B.A. (1964) Factors and processes in the germination of Datura ferox L. Canadian Journal of Botany 42, 11891203.
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.
Toorop, P.E., Van Aelst, A.C. and Hilhorst, H.W.M. (1998) 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. Seed Science Research 8, 483491.
Watkins, J.T., Cantliffe, D.J., Huber, D.J. and Nell, T.A. (1985) Gibberellic acid stimulated degradation of endosperm in pepper. Journal of the American Society for Horticultural Science 110, 6165.
Welbaum, G.E., Muthui, W.J., Wilson, J.H., Grayson, R.L. and Fell, R.D. (1995) Weakening of muskmelon perisperm envelope tissue during germination. Journal of Experimental Botany 46, 391400.

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Effect of low water potential on phytochrome-induced germination, endosperm softening and cell-wall mannan degradation in Datura ferox seeds

  • Rodolfo A. Sánchez (a1), Lucila de Miguel (a1), Carlos Lima (a2) and Rosa M. de Lederkremer (a2)

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