Biochemical Changes Associated with Zygotic Pine Embryo Development

Abstract

Periodically from prefertilization to near maturation, pine (Pinus resinosa Ait. and Pinus strobus L.) ovules were analyzed for several biochemical constituents, and the results were expressed on a fresh weight basis. Lipid accumulated in parallel with the growth of the developing seeds.Soluble protein also accumulated but only in the initial stages of development. ATP content peaked approximately two weeks after fertilization, followed about oneweek later by the energy charge; these peaks were associated with maximal growth stages of the developing embryos. Likewise, peaks of glutathione (GSH) and ascorbic acid (AA), two water soluble reductants, preceded or coincided with the ATP maximum. At late stages of seed development, dissection of the more mature ovules into embryos and gametophytes for analysis revealed that most of the ATP, GSH, and AA was associated with the embryonic tissue.On the other hand, this segregation showed that virtually no proanthocyanidin was located in the developing embryos proper, although they contained other reductants, some of which were probably phenolics. Also, general staining with reagents for phenolics and thiols indicated that the former occurred primarily in -2the developing seed coat, whereas GSH was in the embryo per se.These findings are consistent with roles for ATP, GSH, and AA in the growth and development of zygotic pine embryos; however, it would appear that lipid and protein are being stored for subsequent germination events and that much of the phenolic component is segregated from the developing embryo.

Development and Characterization of in Vitro Embryogenic Systems in Conifers

“…Thus, it appears that proplastids are indicative of early stages of embryonic development, whether in vivo or in vitro. These findings provide evidence in support of our previous biochemical studies (9,33,34) that many aspects of somatic embryogenesis mimic or correspond to in vivo embryogenesis (21).…”

Climate influences on growth and reproduction of Pinus banksiana (Pinaceae) at the limit of the species distribution in eastern North America

“…In Pinus contorta, second-year cones represent 17-45% of the dry mass of the annual shoot (Dick, Leaky, and Jarvis, 1990). Seed mass also increases significantly following fertilization (Singh, 1978), as lipids (Johnson et al, 1987;Tautorus, Fowke, and Dunstan, 1991), protein (Donokaya, Ϫ0.33 0.11 a P: total precipitation from June to August; T: mean temperature between June and August; ring: mean ring index; subscript i: year of cone initiation; subscript p: year of pollination; subscript m: year of seed maturation; subscript mϩ1: year following seed maturation. P values (in parentheses) given for correlations significant at P Յ 0.1; correlations significant at P Ͻ 0.05 shown in boldface.…”

Storage protein gene expression in zygotic and somatic embryos of interior spruce

“…(Bewley and Black 1985, Cyr et al 1991, Flinn et al 1989, and are excellent biochemical markers of zygotic and somatic embryogenesis. However, there are few reports concerning biochemical development in conifer zygotic embryos (see for example Janick et al 1991, Johnson et al 1987) and only recently, during the course of this present study have other labs reported identification and characterization of conifer storage proteins (Gif ford 1988, Gif ford and Tolley 1989, Misra and Green 1990. Clearly, we need to understand the biochemical processes that occur during conifer zygotic embryogenesis before we can evaluate conifer somatic embryos.…”