Photoperiod Effects on Growth Rate of In vitro Cultured Soybean Embryos

Abstract

The growth rate of excised soybean (Glycine max [L.] Merrill) embryos grown in liquid culture increased linearly as photoperiod was increased from 0 to 20 h at an irradiance of 9 W m-2 measured between wavelengths of 700-850 nm from clear incandescent lamps. When irradiance levels were varied between 0.1 and 1.7 W m-2, the maximum growth rates of embryos occurred at ca. 0.5 W m-2 at both 10- and 16-h photoperiods. When the light source was changed from clear incandescent lamps, with a red (600-700 nm) to far-red (700-770 nm) ratio of ca. 1.07, to a BCJ incandescent lamp (Corning Glass dark red, transparent envelope and a red to far-red ratio of ca. 0.19), the growth rate of embryos slowed. These results are consistent with a high irradiance response for growth of soybean embryos.

Transfer cell induction in cotyledons ofVicia faba L.

“…The media composition and culture conditions of our protocol differ only slightly from those of Barratt and Pullen (1984) and Dekhuijzen et al (1988). The temperature regime adopted (27-28 ~ supports optimal growth (Dekhuijzen et al 1988); the use of sucrose as the sole sugar source is consistent with previous protocols for Vicia (Barratt 1984(Barratt , 1986Dekhuijzen et al 1988), pea (Wang et al 1987), and soybean (Raper et al 1984), and the sucrose concentration used is in the mid-range of those reportedly used for Vicia (100mM; 1-5 mM, Barratt 1984Barratt , 1986200 mM, Dekhuijzen et al 1988). This protocol does differ from others in the use of betaine as an osmoticum.…”

“…1 A). The influence of light on cotyledon growth rate has been assessed previously with conflicting results (positive effect: Thompson et al 1977, Raper et al 1984no effect: Dyer et al 1987, Dekhuijzen et al 1988. The issue was therefore revisited by culturing cotyledons with their abaxial surface in contact with the medium either under low light (fluorescent lights, PAR, 16 ,umol/m 2-s; 16-h photoperiod; cf.…”

“…The issue was therefore revisited by culturing cotyledons with their abaxial surface in contact with the medium either under low light (fluorescent lights, PAR, 16 ,umol/m 2-s; 16-h photoperiod; cf. Raper et al 1984) or in the dark. Cotyledon RGR (Fig.…”

“…Finally, the cells potentially receptive to induction form the cotyledon epidermis, thus are directly accessible to inductive agents provided in a bathing medium. Successful protocols for growing cotyledons of grain legumes in liquid medium with or without continuous shaking have been reported (e.g., soybean, Raper et al 1984, Egli 1990pea, Stafford andDavies 1979, Wang et al 1987; broad bean, Barratt andPullen 1984, Dekhuijzen et al 1988). However, to study induction and suppression of transfer cell development in cotyledons, a protocol using an agar-based growth medium was required to allow a specified cotyledon surface to be exposed to the medium.…”

Soybean seed proteome rebalancing

“…Ex vivo zygotic embryo and somatic embryo cultures are often used as proxies for seed maturation; however, there are significant differences in metabolic behavior of embryos that form in vivo and in vitro (see Thompson et al, 1977; Obendorf et al, 1983, 1984; Raper et al, 1984; Finer, 1988; Hayati et al, 1996; Santarem et al, 1997; Chanprame et al, 1998; Pipolo et al, 2004; Iyer et al, 2008; Nishizawa and Ishimoto, 2009; Allen and Young, 2013). RNA expression profiling showed that somatic embryos produce a relatively standard set of seed-specific transcripts (Thibaud-Nissen et al, 2003).…”