• Proceedings of the Plant Resources Society of Korea Conference
• /
• 2003.04a
• /
• pp.124-124
• /
• 2003

In order to study gene expression in a reproductive organ, we constructed a cDNA library of immature flower buds in Korean ginseng and generated expressed sequence tags (ESTs) of 3,360 clones randomly selected. The ESTs could be clustered into 1,844 non-redundant groups. Similarity search of the non-redundant ESTs against public non-redundant databases of both protein and DNA indicated that 1,254 groups show similarity to genes of known function. These ESTs clones were divided into sixteen categories depending upon gene function. The most abundant transcripts were unknown protein (72), chlorophyll a/b-binding protein (48), and stylar glycoprotein. There are no useful informations of gene expression during the development of flower bud in Korean ginseng. These results could help to understand the development of flower bud in Korean ginseng.

• Proceedings of the Korean Society of Plant Biotechnology Conference
• /
• 2005.11a
• /
• pp.27-39
• /
• 2005

a-Ketol linolenic acid [KODA, 9,10-ketol-octadecadienoic acid, or 9-hydroxy-10 -oxo-12(Z), 15(Z)-octadecadienoic acid] was found as a stress-induced factor in Lemna paucicostata. KODA reacts with catecholamines to generate many products that strongly induce flowering in L. paucicostata, although KODA itself was inactive. KODA contains an asymmetric carbon at the 9-position in the molecule; the 9-hydroxyl group is predominantly 9R, with an enantiomeric excess of 40% (70% 9R and 30% 9S). We analyzed two major products of the reaction between KODA and norepinephrine, named FN1 and FN2. FN1 was identified as a tricyclic a-ketol fatty acid, 9(R)-11-{(2'R,8’R,10'S,11'S)-2',8'-dihydroxy-7'-oxo-11'-[(Z)-2-pentenyl]-9'-oxa-4'-azatricyclo[6.3.1.01.5]dodec-5'en-10'-yl}-9-hydroxy-10-oxoundecanoic acid. FN2 was the C-9 epimer of FN1. FN1 was derived from 9R-type KODA and FN2 from 9S-type. FN1 showed strong flower-inducing activity, but FN2 was inactive. Pharbitis nil (violet) is a typical short-day plant; flowering can be induced by exposing a seedling cultivated under continuous light to a single 16-h dark period. We analyzed endogenous KODA levels and showed that they were closely related to flower induction: KODA sharply increased in the later part of a 16-h dark period, on the other hand, it failed to increase in the night-break experiment. In addition to it, KODA increased transiently in immature flower buds in all the plants we examined, including P. nil. No such increase of KODA was seen in foliar buds of P. nil. When KODA was sprayed on seedlings of Pharbitis, flower induction was promoted only by the (R)-form of KODA. We also found that KODA enhances flowering in garden plants such as carnations and impatienses. These phenomena indicate that KODA may be involved in flowering formationg of plants and it is potentially useful for a regulating agent for commercial plant flowering.

• Horticultural Science & Technology
• /
• v.33 no.4
• /
• pp.501-510
• /
• 2015

In this study, we investigated the onset and release of endo-dormancy under natural conditions by observing bud break characteristics in 'Fuji' apple trees using water cuttings. Through examinations of bud break rate and days to bud break, we found that the endo-dormancy of 'Fuji' apple tree continues for 70 d from 165 to 255 d after full bloom (DAFB), from late October to early January of the following year. In addition, within 20 d of first bud break, based on a final bud break rate of 60% or more, we able to identify the timing of the changeover from para-dormancy to endo-dormancy, and endo-dormancy to eco-dormancy. Analysis of the chilling requirement during the endo-dormancy period revealed that chilling accumulation up to 255 DAFB to release endo-dormancy amounted to 666 and 517 h based on the CH and Utah models, respectively. Observation of internal changes in the bud during endo-dormancy showed that flower bud differentiation begins from mid-July, and t ime of inflorescence o f the disk f lower is a vailable to f ind. The f lower buds subsequently developed slowly but steadily during endo-dormancy and in the following year in February, the developmental stage of each organ had progressed. Moreover, the flower buds of 'Fuji' apples were mostly healthy during the dormancy period, but some exhibited necrosis of flower primordium, due partial cell damage from the formation of ice crystals rather than a direct effect of the low temperature. Flower buds were formed in both the axillary buds of bourse shoots and terminal buds of spurs, but lower bud differentiation was observed for the terminal buds of spurs at rate of about 65% of total buds, which was directly related to the bud size and shoot diameter.

• Horticultural Science & Technology
• /
• v.33 no.1
• /
• pp.31-38
• /
• 2015

This study was carried out to investigate the relationship between endogenous polyamines (PAs) and floral bud differentiation in chrysanthemum (Chrysanthemum morifolium). In this study, PA content (free, bound, and conjugated) in apical buds, leaves, and roots changed appreciably during floral bud differentiation. PAs accumulated during series of processes such as floral induction, differentiation of floret primordia, and crown formation in apical buds; changes in PAs in apical buds may have a relationship with those in leaves and roots. The levels of free PAs and conjugated PAs [putrescine (Put) and spermine (Spm)] in apical buds rapidly increased during the initiation stage of floral bud differentiation, while free and conjugated spermidine (Spd) reached their highest levels at the stage of floret primordium differentiation. In the free, conjugated, and bound PA fractions, the changes in Spm content were negligible compared to those of Put and Spd throughout the experiment. These findings indicate that PAs participate in regulating the process of flower bud differentiation in chrysanthemum.

• Bulletin of the Korean Chemical Society
• /
• v.31 no.5
• /
• pp.1381-1384
• /
• 2010

• Bulletin of the Korean Chemical Society
• /
• v.35 no.7
• /
• pp.2159-2161
• /
• 2014

• The Plant Pathology Journal
• /
• v.17 no.6
• /
• pp.347-349
• /
• 2001

Black blights attacked the blossom and flower buds of wild chrysanthemum (Chrysanthemum boreale) in the experimental field in Hamyang in 1998. The infection rate of the disease on the plant ranged from 4.0 to 91.8%. The pathogen isolated from the infected flower buds produced numerous conidia in pycnidia. The pycnidia, which were immersed into the petals, emerged through the epidermis by short ostiolate neck. Conidia had 0-3 septate (mostly uniseptate) and were 10-27.5 $\times$5-7.5 ㎛ in size. The fungus produced pseudothecia on potato dextrose agar (PDA), and uniseptate ascospores produced in asci were 10$\times$2.7 ㎛ in size. The pathogen also produced pycnidia and pycnidiospores on PDA after 4 weeks in the dark condition. The conidia produced on PDA were smaller than those from infected plants. Based on the examined mycological characteristics, the fungus was identified as Didymella chrsanthemi.

• Archives of Pharmacal Research
• /
• v.20 no.4
• /
• pp.363-367
• /
• 1997

From the Chinese crude drug shin-i, the flower buds of Magnolia fargesii, four sesquiterpene, oplopanoe (1), oplodiol (2), homalomenol A (3) and $1{\beta},4{\beta},7{\alpha}$-trihydroxyeudesmane (4) were isolated. These structures were elucidated and the ${13}^C-NMR$ chemical shifts of these compounds were revised by means of various 2D-NMR techniques.

• Natural Product Sciences
• /
• v.20 no.2
• /
• pp.80-85
• /
• 2014

In the course of screening for antioxidant compounds from natural plants in Korea by measuring the radical scavenging effect, a methanol extract of the flower buds of Daphne genkwa S. et Z. (Thymelaeaceae) was found to show a potent antioxidant activity. Subsequent activity-guided fractionation of methanol extract of D. genkwa led to the isolation of four compounds from the ethyl acetate soluble fraction. The chemical structures were elucidated as genkwanin (1), 3'-hydroxygenkwanin (2), apigenin (3), and tiliroside (4) by spectroscopic techniques. Among them, compound 2 showed the significant anti-oxidative effect on DPPH. And compound 2 showed the significant riboflavin-and xanthine-originated superoxide quenching activities. To verify the antioxidant enzymatic activities of compound 2, the SOD enzymatic activity was measured spectrophtometrically using prepared Caenorhabditis elegans homogenates. The results showed that compound 2 was able to elevate SOD activity of C. elegans in a dose dependent manner. Moreover, compound 2 decreased the intracellular ROS accumulation of worms.

• Korean Journal of Plant Tissue Culture
• /
• v.24 no.6
• /
• pp.369-374
• /
• 1997

Immature flower buds of 'Desio' carnation were cultured on MS agar medium supplemented with 1 ㎎/L 2,L-D. Embryogenic calli were formed from 5-10% of the buds less than 20 ㎜ in length, but only non-embryogenic calli were produced from explants of shoot apex leaf, internode, and flowere buds larger than 20 ㎜. The same method was applied to 16 cultivars of cut Sower carnation and embryogenic calli were obtained in 7 cultivars. Several embryogenic callus lines were selected and maintained through subcultures over 120 weeks without loss of embryogenic competence. The embryogenic cultures were also proliferated rapidly in liquid agitation cultures using MS medium supplemented with 1mg/L 2,4-D. Numerous embryos were formed on the periphery of the cell aggregates upon transfer to auxin-free MS agar medium. Plantlets were transplanted in potting soil and grown to bloom in six months.