• BMB Reports
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• 제40권6호
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• pp.1083-1089
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• 2007

The HAP complex has been found in many eukaryotic organisms. HAP recognizes the CCAAT box present in the promoters of 30% of all eukaryotic genes. The HAP complex consists of three subunits - HAP2, HAP3 and HAP5. In this paper, we report the biological function of the AtHAP3b gene that encodes one of the HAP3 subunits in Arabidopsis. Compared with wild-type plants, hap3b-1 and hap3b-2 mutants exhibited a delayed flowering time under long-day photoperiod conditions. Moreover, the transcription levels of FT were substantially lower in the mutants than in the wild-type plants. These results imply that AtHAP3b may function in the control of flowering time by regulating the expression of FT in Arabidopsis. In a subsequent study, AtHAP3b was found to be induced by osmotic stress. Under osmotic stress conditions, the hap3b- 1 and hap3b-2 mutants flowered considerably later than the wild-type plants. These results suggest that the AtHAP3b gene plays more important roles in the control of flowering under osmotic stress in Arabidopsis.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2022년도 추계학술대회
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• pp.51-51
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• 2022

Water dropwort (Oenanthe stolonifera DC.) is a perennial herbaceous plant that grows wild throughout Korea. As of 2020, 24,819 tons (51.7% of open field, 48.3% of facility) are produced in 1,278 ha (59.9% of open field, 40.1% of facility) nationwide. Water dropwort, which is rich in nutrients such as vitamins and iron, is mainly cultivated by vegetative propagation method using local traditional species, however, seed propagation and breeding of cultivars are insufficient so far. Since securing, propagating and continuous characterization of various genetic resources are required to breed new cultivars, this study was conducted to compare the main characteristics of domestic genetic resources and to improve their utilization. Growth characteristics such as plant height, fresh weight, plant type, and flowering date were investigated for the 89 varieties of genetic resources owned by Jeollabuk-do Agricultural Research and Extension Services after vegetative propagation in the individual pots. Also, the morphological image information of leaves and flowers was constructed. Genetic resources were collected nationwide and originated in 30 regions including Hwaseong, Siheung and Jeju. Their plant types could be classified into straight, intermediate and creeping types according to their morphological characteristics, and at this time, the number of intermediate types accounted for the largest proportion. Flowering was carried out under high-temperature and long-day conditions in summer. According to the flowering date, they could be classified into early, middle and late flowering varieties, and at this time, the middle flowering varieties occupied the largest proportion. As a result of the investigation of vegetative growth characteristics, varieties with long plant height, heavy fresh weight and thick stem thickness were identified. Along with this result, it is thought that classification and selection of genetic resources for various purposes will be possible through additional investigations such as analysis of components and antioxidant activity. Moreover, it is judged that such results can be used as basic data for breeding new water dropwort cultivars in the future.

• 식물분류학회지
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• 제37권4호
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• pp.323-333
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• 2007

The degree to which parallel evolution utilizes the same genetic mechanisms indicates the degree to which developmental processes constrain or channel phenotypic evolution. A transgenetic strategy was used to elucidate the role of one floral meristem identity gene, LEAFY (LFY), in the evolution of rosette flowering, a plant architecture that has evolved in parallel in several lineages of the mustard family, Brassicaceae. The LFY genes from three rosette flowering species were cloned and introduced into a species with the ancestral architecture, and results indicated that changes at the LFY locus contributed to the evolution of rosette flowering in two of the three lineages, but that in each lineage a different set of genetic partners was involved. Also, LFY was shown to play a role in the evolution of flower size. Transgenetic strategy may be useful in the study of plant morphological evolution and parallelism.

• Journal of Plant Biology
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• 제32권4호
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• pp.255-264
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• 1989

Ginseng zygotic embryos, seedlings, and exised cotyledonary nodes were cultured on Murashinge and Skoog's(MS) medium, supplemented with 6-benzyladenine(BA) and gibberellic acid(GA3) to induce flower buds. As the concenteration of nitrogen compounds in MS medium was reduced to half of its strength, the flowering frequency of zygotic embryos increased up to 90%. The optimum concentration of sucrose in the medium for flowering of seedlings was 30-60 g/1. In all cases flower buds were formed on elongated axillary branches from the cotyledonary nodes, while the apices remained vegetative. When zygotic embryos and excised cotyledonary nodes were cultured on the medium, supplemented with all possible combinations of BA, GA3, and abscisic acid(ABA) of 5 $\mu$M indole-3-acetic acid(IAA) in the above combinations did not affect flowering. These results suggest that cytokinins, gibberellins, and inhibitors play primary, permissive, and preventive roles, respectively, in the induction of flowering of ginseng.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.100-100
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• 2017

FT is one of the major floral activator in plant flowering. FT determines the changing point of time from vegetative stage to reproductive stage. To understand the role of FT homologs in short-day plant soybean, we identified 10 soybean FT homologous genes and named GmFTs. We figured out that 10 GmFT genes were further categorized into three subclades through phylogenetic analysis. Expression analysis of GmFT genes indicated that they might have different functions in photoperiod-dependent soybean flowering. Most of GmFTs, for example, GmFT2a, GmFT2b, GmFT5a and GmFT6 mainly expressed in soybean leaves at short-day condition. However, interestingly GmFT1a and GmFT4 represented opposite expression pattern to other GmFTs. Arabidopsis transgenic plants overexpressing GmFT2a and GmFT5a exhibited extremely early flowering. In contrast, overexpression of GmFT4 delayed flowering of Arabidopsis transgenic plants. The results suggest that GmFT4 has antagonistic role to other GmFTs in soybean flowering. Interestingly, mRNA level of GmFT2a is higher in early flowering soybean accessions than in late flowering ones. Moreover, the highest point of mRNA level of GmFT2a showed the positive correlation with the timing of flowering of soybean accessions. But that of GmFT4 showed opposite pattern. Here, we report that soybean FT homologs might acquire different functions in photoperiod-dependent flowering through the functional diversification during evolution.

• 농업과학연구
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• 제40권4호
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• pp.305-309
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• 2013

A freesia (Freesia hybrida Hort.) 'Dancing Flame' was developed for the cut flower in the National Institute of Horticultural Herbal Science in 2007. This hybrid was selected from a crossing between a seedling 'Vulcano' and 'Sailor', which is scarlet double flowering and purple single flowering, respectively, and 'Figaro' which is bright red color and semi-double flowering, in 2000. Morphological characteristics of the selected hybrid were investigated for 3 years from 2005 to 2007, and then it was named 'Dancing Flame'. 'Dancing Flame' had red color (RHS R44B) and single flower with yellow center color (RHS Y9A). The growth of the plant was vigorous and the average height was 93.3 cm. The average flower width was 60 mm, number of floret per stalk was 14.3, and stalk was 13.2 cm length. The average yield, 7.8 cuttings per plant, was 2.5 stems per plant more than the control cultivar. The average days to first flowering of 'Dancing Flame', 133 days, was approximately 5 days earlier than the control cultivar. And its average yield, 7.1 cormlet per plant, was also 2.5times more than the control cultivar.

• 한국식물생명공학회:학술대회논문집
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• 한국식물생명공학회 2005년도 추계학술대회 및 한일 식물생명공학 심포지엄
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• pp.27-39
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• 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.

• BMB Reports
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• 제51권4호
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• pp.163-164
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• 2018

CONSTANS (CO) induces the expression of FLOWERING LOCUS T (FT) in the photoperiodic pathway, and thereby regulates the seasonal timing of flowering. CO expression is induced and CO protein is stabilized by FLAVIN-BINDING KELCH REPEAT F-BOX PROTEIN 1 (FKF1) in the late afternoon, while CO is degraded by CONSTITUTIVE PHOTOMORPHOGENIC 1 (COP1) during the night. These regulatory cascades were thought to act independently. In our study, we investigated the relationship between FKF1 and COP1 in the regulation of CO stability in response to ambient light conditions. A genetic analysis revealed that FKF1 acts as a direct upstream negative regulator of COP1, in which cop1 mutation is epistatic to fkf1 mutation in the photoperiodic regulation of flowering. COP1 activity requires the formation of a hetero-tetramer with SUPPRESSOR OF PHYA-105 (SPA1), [$(COP1)_2(SPA1)_2$]. Light-activated FKF1 has an increased binding capacity for COP1, forming a FKF1-COP1 hetero-dimer, and inhibiting COP1 homo-dimerization at its coiled-coil (CC) domain. Mutations in the CC domain result in poor COP1 dimerization and misregulation of photoperiodic floral induction. We propose that FKF1 represses COP1 activity by inhibiting COP1 dimerization in the late afternoon under long-day conditions, resulting in early flowering.

• 화훼연구
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• 제26권4호
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• pp.179-186
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• 2018

Ranunculus asiaticus characterizes colorful and attractive flower shapes that are related with the ornamental value of bulbous plants. Improving ornamental value of bulbous flowers has been the general goal of floricultural market. Gibberellic acid ($GA_3$) and benzyladenine (BA) play an important role in growth and developmental processes in floriculture. Combinational treatments of these two hormones have been used in floriculture to improve flower quality. We assessed the effects of combined $GA_3$ and BA, as well as the individual effects of each hormone, on growth characteristics using soil drench application to eight R. asiaticus cultivars, 'Giallo Millepetali', 'Bianco Millepetali', 'Arancio Millepetali', 'Rosa SC', 'Arancio Pratolino', 'Giallo Pratolino', 'Bianco Pratolino', and 'Rosa Ch Pratolino'. $GA_3$ treatments increased plant height and first flower size of R. asiaticus cultivars. Moreover, about 5 to 9 days to flowering were averagely shortened by $GA_3$ treatments compared to controls. On the other hand, the opposites, including first flower size and days to flowering, were observed for cultivars treated with BA, compared with controls. Treatments of $GA_3$ + BA generally affected growth traits, such as plant height, flower size, and the timing of flowering on some R. asiaticus cultivars. In particular, about 5 to 6 days to flowering were reduced on average by Treatments of $GA_3$ + BA. Our results showed positive growth effects, including plant height, days to flowering, first flower height, number of flowers from the application of individual and combined hormones to R. asiaticus cultivars and demonstrate a role for these hormones in future bulbous floriculture.

• 한국산림과학회지
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• 제96권6호
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• pp.699-704
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• 2007

한국 자생 노랑붓꽃과 금붓꽃을 초봄의 분화로서의 가치를 구명하기 위하여 11 월 1일부터 12월1일까지 15일 간격으로 3차례 입실하였고, $7^{\circ}C$, $12^{\circ}C$와 $15^{\circ}C$의 온도 처리구에 12월1일에 입실시켜 개화 및 생육에 미치는 영향을 조사하였다. 노랑붓꽃과 금붓꽃은 입실시기가 지연될수록 초장이 커지고 엽수가 많아졌다. 노랑붓꽃을 11윌 1일에 입실한 것은 전혀 개화를 하지 않았으나 11윌 16일에 입실한 것은 30%를 개화하였고, 12윌1일에 입실한 것은 100% 개화하였다. 한편 금붓꽃은 11월1일부터 12월 1일 사이에 입실한 것 모두가 개화되었다. 개화주의 개화수와 개화기는 차이가 없었다. 한편 입실온도가 증가할수록 초장과 엽장이 작아지고 엽수가 현저히 많아졌다. 노랑붓꽃을 $12^{\circ}C$와 $15^{\circ}C$에 입실한 것은 전혀 개화를 하지 않았으나 $7^{\circ}C$에 입실한 것은 100% 개화하였다. 금붓꽃을 $15^{\circ}C$에 입실한 것은 전혀 개화를 하지 않았으나 $12^{\circ}C$에 입실한 것은 30% 개화하였고 $7^{\circ}C$에 입실한 것은 100% 개화하였으며 개화시기가 빠르고 화경 및 화경장이 길었다.