• Korean Journal of Weed Science
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• v.9 no.1
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• pp.56-68
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• 1989

aA series of experiments were conducted to investigate the effect of plant growth regulator treatments on the growth and lateral root formation in soybean sprouts in order to establish the effective method of producing root-less or short-rooted soybean sprouts with larger diameter in the hypocotyl. Major results can be summarized as follows. 1. Soybean sprouts showed fairly uniform elongation rate from 3 to g days after imbibition with daily increase of 3.8cm. The speed of elongation of hypocotyl was reduced whereas that of root accelerated 7 days after imbibition. Lateral roots began to emerge fairly evenly from 5 to 9 days after imbibition with a daily increase of 4.4. 2. Auxins(IAA, IBA, NAA, 2,4-D) inhibited hypocotyl elongation and formation of lateral roots and increased hypocotyl diameter without influencing root length and hook diameter at higher concentrations. The dry weight of cotyledon was increased significantly as compared to that of hypocotyl and root. Among the tested auxins, 2, 4-D was the most effective. 3. BA and 4PU-30 significantly reduced elongation of hypocotyl and root and resulted in the biggest diameter of hypocotyl when treated at higher concentrations. The lowest effective concentration of BA to prevent the formation of larval gal roots was 12.5ppm. The formation of lateral roots could be completely prevented by BA and 4PU-30 treatment but kinetin, zeatin, zeatin riboside resulted in many lateral roots and increased thickness of soybean sprouts with little influence. Cotyledon deformation was found in soybean sprouts treated by 4PU-30. 4. 2, 4-D was the most effective for increasing the hypocotyl diameter while 4PU-30 was the most effective for reducing no. of lateral roots. 5. It can be concluded that among the plant growth regulators tested, BA was effective in reducing root length and increasing hypocotyl diameter. BA 12.5 ppm or 15 ppm may thus be the more practical for production of soybean sprouts. 6. ABA showed no significant effect of growth parameter, however ABA 25 ppm inhibited only no of lateral roots with little influence on the growth of seedling. 7. Ethephon inhibited the elongation of hypocotyl and root and increased hypocotyl diameter at higher concentrations. 8. The combined effect of cytokinins and ethephon was very similar to result of BA treatment alone. As the ethephon concentration increased, hypocotyl diameter and dry weight of cotyledon tended to increase.

• Journal of Plant Biotechnology
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• v.35 no.3
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• pp.177-183
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• 2008

Ac/Ds mutant lines of this study were transgenic rice plants, each of which harbored the maize transposable element Ds together with a GUS coding sequence under the control of a promoterless(Ds-GUS). We selected the mutants that were GUS expressed lines, because the GUS positive lines will be useful for identifying gene function in rice. One of these mutants was identified knock-out at Oszinc626(NP_001049991) gene, encoding a RING-H2 zinc-finger protein, by Ds insertion. In this mutant, while primary root development is normal, secondary root development from lateral root was very poor and seed development was incomplete compare with normal plant. RING zinc-finger proteins play important roles in the regulation of development in a variety of organisms. In the plant kingdom, a few genes encoding RING zinc-finger proteins have been documented with visible effects on plant growth and development. The consensus of the RING-H2(C3-H2-C3 type) domain for this group of protein is $Cys-X_2-Cys-X_{28}-Cys-X-His-X_2-His-X_2-Cys-X_{14}-Cys-X_2-Cys$. Oszinc626 encodes a predicted protein product of 445 amino acids residues with a molecular mass of 49 kDa, with a RING-zinc-finger motif located at the extreme end of the C-terminus. RT-PCR analysis indicated that the expression of Oszinc626 gene was induced by IAA, cold, dehydration, high-salinity and abscisic acid, but not by 2,4-D, and the transcription of Oszinc626 gene accumulated primarily in rice immature seeds, root meristem and shoots. The gene accumulation patterns were corresponded with GUS expression.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2003.04a
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• pp.61-62
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• 2003

Clonal propagation of high-value forest trees through somatic embryogenesis (SE) has the potential to rapidly capture the benefits of breeding or genetic engineering programs and to improve raw material uniformity and quality. A major barrier to the commercialization of this technology is the low quality of the resulting embryos. Several factors limit commercialization of SE for Corsican pine, including low initiation rates, low culture survival, culture decline causing low or no embryo production, and inability of somatic embryos to fully mature, resulting in low germination and reduced vigour of somatic seedlings. The objective was to develop a Corsican pine maturation medium that would produce cotyledonary embryos capable of germination. Treatments were arranged in a completely randomized design. Data were analyzed by analysis of variance, and significant differences between treatments determined by multiple range test at P=0.05. Corsican pine (Pinus nigra var. maritima) cultures were initiated on modified !P6 medium. Modifications of the same media were used for culture multiplication and maintenance. Embryogenic cultures were maintained on the same medium semi solidified with 2.5 g/l Gelrite. A maturation medium, capable of promoting the development of Corsican pine somatic embryos that can germinate, is a combination of iP6 modified salts, 2% maltose, 13% polyethylene glycol (PEG), 5 mg!l abscisic acid (ABA), and 2.5 g/l Gelrite. After initiation and once enough tissue developed they were grown in liquid medium. Embryogenic cell suspensions were established by adding 0.951.05 g of 10- to 14-day-old semisolid-grown embryogenic tissue to 9 ml of liquid maintenance media in a 250ml Erlenmeyer flask. Cultures were then incubated in the dark at 2022$^{\circ}$C and rotated at 120 rpm. After 2.53 months on maturation medium, somatic embryos were selected that exhibited normal embryo shape. Ten embryos were placed horizontally on 20 ml of either germination medium ($\frac{2}{1}$strength Murashige and Skoog (1962) salts with 2.5 g/l activated charcoal) or same medium with copper sulphate adjusted to 0.25 mg/1 to compensate for copper adsorption by activated carbon. 2% and 4% maltose was substituted by 7.5% and 13% PEG respectively to improve the yield of the embryos. Substitution of' maltose with PEG was clearly beneficial to embryo development. When 2% of the maltose was replaced with 7.5% PEG, many embryos developed to large bullet-shaped embryos. At latter stages of development most embryos callused and stopped development. A few short, barrel-shaped cotyledonary embryos formed that were covered by callus on the sides and base. When 4% of the maltose was removed and substituted with 13% PEG, the embryos developed further, emerging from the callus and increasing yield slightly. Microscopic examination of the cultures showed differing morphologies, varying from mostly single cells or clumps to well-formed somatic embryos that resembled early zygotic embryos only liquid cultures with organized early-stag. A procedure for converting and acclimating germinants to growth in soil and greenhouse conditions is also tested. Seedling conversion and growth were highly related to the quality of the germinant at the time of planting. Germinants with larger shoots, longer, straighter hypocotyls and longer roots performed best. When mature zygotic embryos germinate the root emerges, before or coincident with the shoot. In contrast, somatic embryos germinate in reverse sequence, with the cotyledons greening first, then shoot emergence and then, much later, if at all, the appearance of the root. Somatic seedlings, produced from the maturation medium, showed 100% survival when planted in a field setting. Somatic seedlings showed normal yearly growth relative to standard seedlings from natural seed.