Polyamine Titer in the Embryonic Axis and Cotyledons of Glycine max (L.) during Seed Growth and Maturation

Abstract

Active polyamine metabolism occurs in Glycine max (L.) seeds during development. Most (:97%) of putrescine (Put), spermidine (Spd), spermine (Spm), and cadaverine (Cad) are present as free forms in the growing embryo. In the cotyledon or embryonic axis, Put gene(s) and/or formation ofa-amylase in isolated barley aleurone layers (8).To examine possible roles of polyamines in seed development, we have chosen soybeans for two major reasons. First, mature soybean seed apparently contain a high level of Cad (15), particularly in the embryonic axis (16). Our preliminary results indicate that the content of Cad in the embryonic axes of soybean seeds is unusually high (0.1% of the axis dry weight) as compared to other crop seeds (7). Thus, it would be important to know at what developmental stage ofthe embryos Cad is synthesized and accumulated, and ofwhat possible physiological significance Cad synthesis and accumulation is to the embryonic development and seed viability. Second, unlike many plant species, regeneration of soybean plants from cell or tissue culture via somatic embryogenesis appears to be difficult at present. Study of the role of polyamines in the development and growth of soybean embryos, particularly the embryonic axes, may provide new insights into problems related to somatic embryogenesis of soybeans in culture. Accordingly, we have examined polyamines and their titers in the embryonic axes and cotyledons of both field-and greenhouse-grown soybeans during seed development. Experiments have also been conducted to alter the seed growth pattern during cell expansion to study the relations ofpolyamine level to seed maturation and seed viability. MATERIAILS AND METHODSBiological Material. Soybean (Glycine max L. Merr.) cv Miles and Williams were planted in late May of 1981May of , 1982May of , and 1983 at the Agricultural Experimental Farm of the University of Kentucky in Lexington, Kentucky. The seeds were sown in a field where soybeans had been grown in previous years and conventional management practices were followed. In early August of each year, pods containing embryos of the appropriate size were selected (tagged or marked) by looking through young pods against sunlight. Seed

Changes in polyamines content associated with zygotic embryogenesis in the Brazilian pine, Araucaria angustifolia (Bert.) O. Ktze.

“…The Put/Spd+Spm ratio has been correlated with the synthesis of macromolecules (Lin et al 1984). In Araucaria angustifolia the proportion between the Put levels and the other PAs was higher during the initial phases of seed development, corresponding to the cellular multiplication and elongation (stages 1 to 3), with a reduction in the final stages, corresponding to stabilization of the dry matter content (figure 3).…”

Spermidine metabolism in parasitic protozoa - a comparison to the situation in prokaryotes, viruses, plants and fungi

“…Spermidine and cadaverine were both found to increase in seeds of Pisum sativum during germination (Lin et al 1984). The effect on root formation and growth has been reported.…”

Cadaverine

“…13 However, in legumes the biosynthesis is proposed to be ontogenic and suggested to be higher only during growth period of embryonic axes than that of the developing and mature cotyledon of G.max. 82 The downregulation of Cad in mature seed embryo due to defoliation and shading is also proposed. 82 The reduction of ldc gene expression in rice with different developmental stages ( Fig.…”

“…82 The downregulation of Cad in mature seed embryo due to defoliation and shading is also proposed. 82 The reduction of ldc gene expression in rice with different developmental stages ( Fig. 3) using gene investigator software is predicted (www.geneinvestigator.com).…”

“…139 The downregulation of LDC is also known. 82 The Cad differential distribution in specific tissue during developmental stages of plants also indicates titer regulation under ontogenic development. Gamarnik and Frydman, 87 found considerably high Cad in embryonic axes than cotyledons of G.max.…”