Regulation of the Onset of Dormancy in Tubers of Begonia evansiana

Abstract

The concept of dormancy as a condition of repressed genetic information was first proposed by Tuan and Bonner (7). from experiments which showed an increased template activity of chromatin isolated from potato tutbers upon emergence from dormancy. The repressioni concept has since received general acceptance (1). It were supplied with the various inhibitors in the solution used to moisten the filter paper. After the 20 days of dormancy induction, the tubers were rinsed and placed on paper moistened with water.The effectiveness of the dormancy inducing treatments is illustrated in Fig. 1, showing the progress

Effects of Oxygen and Respiratory Inhibitors on Induction and Release of Dormancy in Aerial Tubers of Begonia evansiana

“…The treated tubers were washed several times with water just before and 5 days after the start of the photo-sprouting test. The percentage of sprouting at 60 days after the beginning of the inhibitor treatment is shown in Table II. All the chemicals tested, though less effective than the inhibitors of RNA and protein biosyntheses (8), actually promoted photo-sprouting irrespective of light conditions during the pretreatments. The present results support the view that 02 promotes dormancy development by facilitating the oxidative phosphorylation.…”

“…An earlier paper has suggested the participation in dormancy induction of a specific protein, the synthesis of which is dependent on actinomycin D-insensitive mRNA (8). The necessity of 02 in inducing bud dormancy in Begonia tubers (Fig.…”

“…If the isolated immature tubers are exposed to red light or moderately low temperatures, however, they advance to the thermo-sprouting state (7). Dormancy-inducing effects of these treatments are negated by the application of inhibitors of biosyntheses of nucleic acids and proteins, which suggests that the DNA-RNA-mediated biosynthesis of proteins is an important event in the development of dormancy in the Begonia tuber (8). On the other hand, some workers have recently reported that some respiratory inhibitors as well as the inhibitors of nucleic acid and protein biosyntheses stimulate seed germination (2,3,9).…”

Protein Synthesis in Dormant and Non‐Dormant Cocklebur Seed Segments

“…On the other hand, seed germination in dicotyledonous plants occurs when the sum of growth potentials of both the axial and cotyledonary tissues overcomes the bloek imposed by the seed eoat (Esashi and Leopold 1968). Protein synthesis has been assumed to be required for the initiation of axial cell elongation (Brooker et al 1977), suggesting that seed dormaney may be maintained by interference of protein synthesis.…”

“…Protein synthesis has been assumed to be required for the initiation of axial cell elongation (Brooker et al 1977), suggesting that seed dormaney may be maintained by interference of protein synthesis. Nevertheless, it has been reported that seed germination can occur in the presence of inhibitors of protein synthesis (see Mayer and Shain 1974), and that the inhibitors can induce the sprouting of tuberous buds in some herbaceous plants by interfering with their dormaney development (Esashi and Leopold 1969, Okagami 1978, Tanno and Okagami 1978. These results may imply the involvement of some kind of protein biosynthesis in the maintenanee of dormaney.…”