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In situ expression of two storage protein genes in relation to histo-differentiation at mid-embryogenesis in Medicago truncatula and Pisum sativum seeds

Abirached-Darmency, M., Abdel-gawwad, M. R., Conejero, G., Verdeil, J. L., Thompson, R.
Journal of experimental botany 2005 v.56 no.418 pp. 2019-2028
Medicago truncatula, Pisum sativum, peas, field crops, forage crops, gene expression, seed development, embryogenesis, embryo (plant), histology, cell differentiation, messenger RNA, nucleic acid hybridization, genes, storage proteins
The seed consists of several layers of specialized cell-types that divide and differentiate following a highly regulated programme in time and space. A cytological approach was undertaken in order to study the histo-differentiation at mid-embryogenesis in Medicago truncatula as a model legume, and in Pisum sativum using serial sections of embedded immature seed. Little published information is available about seed development in Medicago species. The observations from this study revealed a number of distinctive features of Medicago seed development and differentiation. Transfer cells, involved in nutrient transfer to the embryo, were clearly identified in the thin-walled parenchyma of the innermost integument. Histological Schiff-naphthol enabled carbohydrate accumulation to be followed in the different seed compartments, and revealed the storage protein bodies. Non-radioactive mRNA in situ hybridization, was carried out using mRNA probes from two highly expressed genes encoding the major vicilin and legumin A storage protein types. The timing of mRNA expression was related to that of the corresponding proteins already identified.