Characterization of the developmental stages of cypress zygotic embryos by two‐dimensional electrophoresis and by cytochemistry

Abstract

Biochemical changes that characterize megagametophyte and zygotic embryo development in the conifer Cupressus sempervirens L. (Cupressaceae) were studied by complementary methods of cytochemistry and two-dimensional electrophoresis (2-DE). These analyses revealed that early in their development megagametophytes and embryos were characterized by the predominant elaboration of starch in association with a low protein content. As their development proceeded, starch content gradually decreased while protein body synthesis progressively intensified, both in the megagametophyte and the embryo. In parallel, an increase in protein level as well as an accumulation of specific polypeptides could be observed in the two tissues. During maturation, protein bodies accumulated to high levels both in megagametophyte and embryo cells, whereas starch could no longer be detected. Protein levels were high in mature seeds and reached 12% and 8% of the megagametophyte and embryo DW, respectively. Some sets of polypeptides accumulated more specifically at this time in both megagametophyte and embryo. Some of these began to first accumulate in the megagametophyte during embryo development before their concentration rose in the embryo at cotyledonary stage. Others displayed a more specific-embryo accumulation pattern.

Protein expression during seed development in Araucaria angustifolia: transient accumulation of class IV chitinases and arabinogalactan proteins

“…In A. angustifolia, despite its recalcitrant nature, seed protein accumulation and protein electrophoretic patterns resembled those reported for orthodox conifer seeds (Hakman 1993, Sallandrouze et al 2002. The initial increase followed by a decrease in polypeptide abundance during seed formation relates to the morphological modifications during embryo development.…”

IAA, ABA, polyamines and free amino acids associated with zygotic embryo development of Ocotea catharinensis

“…There are several studies relating the synthesis and accumulation of storage proteins with different stages during embryogenesis (Stone and Gifford 1997;Chatthai and Misra 1998;Silveira et al 2004a). In general, increased accumulation of protein is observed during embryo development (Sallandrouze et al 2002). The profile of amino acids changes during seed development may reflect the balance between production and utilization, where small changes in the rate of protein synthesis may result in alterations of specific amino acids (Macnicol 1983).…”

“…It can usually be divided into two main steps: (1) an initial morphogenic phase characterized by cell division and the onset of cell differentiation, followed by (2) a maturation phase that involves the accumulation of major storage products and preparation for seed desiccation, dormancy and germination (Mordhorst et al 1997;Sallandrouze et al 2002).…”

Dynamics of biochemical and morphophysiological changes during zygotic embryogenesis in Acca sellowiana (Berg.) Burr.

“…It can usually be divided into two main steps, namely, (1) an initial morphogenetic phase which is characterized by cell division and the onset of cell differentiation, followed by (2) a maturation phase associated with the accumulation of major storage products and preparation for seed desiccation, dormancy and germination (Mordhorst et al 1997;Sallandrouze et al 2002).…”