• 한국어업기술학회:학술대회논문집
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• 한국어업기술학회 2000년도 춘계수산관련학회 공동학술대회발표요지집
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• pp.383-384
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• 2000

Most of the photoperiodic responses result in a sharp contrast between development in long and short days, so that qualitative observations are quite sufficient to establish that development is under photoperiodic control, and qualitative information of this type is all that is available for many of the responses (Dring 1984). However, we need to devise some quantitative measurement of the response in order to study the physiological mechanism of photoperiodic control. We report here the quantification of photoperiodic control of erect thalli production of Sargassum muticum in different daylength regimes. (omitted)

• Journal of Plant Biology
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• 제19권1호
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• pp.14-18
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• 1976

Inhibition of flowering in Lemna perpusilla 6746 by 30 mM sucrose was reversed by the addition of acetylcholine (>$10^{-4}M) supplemented with 10^{-4}M$ ascorbic acid to 1/10-strength Hunter's growth medium. The reversible effect of acetylcholine was found to be greater at early stages of flowering than in the later period. Promotive effects of both acetylcholine ($10^{-3}M) and eserine(10^{-5}M$) on flowering in the short-day plant under various photoperiodic conditions were studied. It was indicated that the application decreased length of the critical dark period for the floral induction, and it was also shown that the endogenous status of acetylcholine was involved in the floral response which had a correlation with phytochrome. Interruption of inductive dark periods by red irradiation (1min) immediately followed by far-red light (1 min) completely inhibited flowering, while the addition of acetylcholine and eserine to the medium under the same condition slightly promoted flowering, indicating possible involvement of phytochrome system in acetylcholine activity for photoperiodic sensitivity of floral response in Lemna perpusilla 6746.

• Journal of Microbiology and Biotechnology
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• 제29권9호
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• pp.1453-1459
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• 2019

Zeaxanthin is an important pigment in the photo-protection mechanism of microalgae. However, zeaxanthin epoxidase, an enzyme involved in the accumulation and conversion of zeaxanthin, has not been extensively studied in microalgae. In this work, we report the expression pattern of zeaxanthin epoxidase in Dunaliella tertiolecta (DtZEP) at different light and diverse salinity conditions. To confirm the responsiveness to light conditions, the ZEP expression pattern was investigated in photoperiodic (16 h of light and 8 h of dark) and continuous (24 h of light and 0 h of dark) light conditions. mRNA expression levels in photoperiodic conditions fluctuated along with the light/dark cycle, whereas those in continuous light remained unchanged. In varying salinity conditions, the highest mRNA and protein levels were detected in cells cultured in 1.5 M NaCl, and ZEP expression levels in cells shifted from 0.6 M NaCl to 1.5 M NaCl increased gradually. These results show that mRNA expression of DtZEP responds rapidly to the light/dark cycle or increased salinity, whereas changes in protein synthesis do not occur within a short period. Taken together, we show that DtZEP gene expression responds rapidly to light irradiation and hyperosmotic stress. In addition, ZEP expression patterns in light or salinity conditions are similar to those of higher plants, even though the habitat of D. tertiolecta is different.

• 한국발생생물학회지:발생과생식
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• 제19권1호
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• pp.11-17
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• 2015

This study investigated possible involvement of photoperiodic regulation in reproductive endocrine system of female olive flounder. To investigate the influence on brain-pituitary axis in endocrine system by regulating photoperiod, compared expression level of Kisspeptin and sbGnRH mRNA in brain and FSH-${\beta}$, LH-${\beta}$ and GH mRNA in pituitary before and after spawning. Photoperiod was treated natural photoperiod and long photoperiod (15L:9D) conditions from Aug. 2013 to Jun. 2014. Continuous long photoperiod treatment from Aug. (post-spawning phase) was inhibited gonadal development of female olive flounder. In natural photoperiod group, the Kiss2 expression level a significant declined in Mar. (spawning period). And also, FSH-${\beta}$, LH-${\beta}$ and GH mRNA expression levels were increasing at this period. However, in long photoperiod group, hypothalamic Kiss2, FSH-${\beta}$, LH-${\beta}$ and GH mRNA expression levels did not show any significant fluctuation. These results suggest that expression of hypothalamic Kiss2, GtH and GH in the pituitary would change in response to photoperiod and their possible involvement of photoperiodic regulation in reproductive endocrine system of the BPG axis.

• Fisheries and Aquatic Sciences
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• 제22권1호
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• pp.4.1-4.10
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• 2019

Russian sturgeon (Acipenser gueldenstaedtii) is commercially important in Korea because its caviar is highly prized. Although the early ontogeny of the species has been described, behavioral modifications in response to various light intensities or diel photoperiodicity patterns have not been studied extensively. The objective of the present study was to examine the behavioral characteristics of hatchery-produced A. gueldenstaedtii prelarvae over a diel photoperiodic cycle. During a diel light cycle comprising 16 h of daylight (450 lx), 4 h of dim light (10 lx), and 4 h of darkness (< 1 lx), newly hatched A. gueldenstaedtii prelarvae exhibited negative phototaxis in daylight (day 0-day 2), and this early behavior was not significantly affected by changes of light intensities. Rheotactic and non-rheotactic aggregation into schools was typical between days 3 and 6. Under the diel light cycle conditions described, rheotaxis was not influenced by environmental light intensity as much as non-rheotactic schooling behavior. Post-schooling behavior, which progressed from day 7 to day 8, did not change significantly during the diel light cycle. The data from the present study could be of practical value in developing a visual guide for assessing the fitness and quality of Russian sturgeon prelarvae under diel light cycle conditions in hatcheries.

• 한국산림과학회지
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• 제88권4호
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• pp.523-532
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• 1999

본 연구는 자연 삼림욕장을 방문하기 어려운 장애인, 환자, 도시근로자들을 위하여 도시내 건물옥상 또는 유휴공간에 자연 삼림욕장의 기능을 대체할 수 있는 도시형 온실 삼림욕장을 개발하기 위하여 수행되었다. 시험용 저에너지 투입 이중비닐 삼림욕장을 축조하여 겨울철, 여름철 욕장환경을 조사하였으며, 이러한 욕장에 적합한 방향성 자생 및 외래 목, 초본식물들을 탐색하였다. 또한 후보식물들의 겨울철 저온, 여름철 고온에 대한 생장반응과 광주기 반응을 관찰하였다. 겨울철 이중비닐 욕장내 조절된 밤 최저온도는 $-2^{\circ}C$로써 대부분의 초본류는 동사하지는 않았으나 생장이 정지된 상태로 있다가 4월 초에 생장이 개시되었다. 외래초본 중 Catnip faassen's(Nepeta x faassenii)와 Lemon bergamot (Monarda citriodora)는 장일조건에서 생장이 촉진되었다. 이른봄 구상나무, 눈측백나무, 장백소나무와 같은 목본류의 생장율은 주로 밤 최저온도에 영향을 받았으며 광주기조건에는 큰 영향을 받지 않는 것으로 나타났다. 고온비닐온실에서 자생초본, 방아풀, 들깨풀, 배초향, 더덕은 16시간의 장일조건에서 생장이 촉진되었다. 소나무는 여름철 $40^{\circ}C$이상의 고온에서 수고생장 및 근원경생장이 억제되었다.

• 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.

• 한국작물학회지
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• 제8권1호
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• pp.111-115
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• 1970

1) 본 실험은 Y.S.A. Gold leaf, oxford 1, Awha Yungzung, Samsun, Maruha, Hatano, 등 8개 품종을 온도와 일장 반응으로 본 것이다. 2) 온도는 저온을 야외(10~$20^{\circ}$) 고온을 온실($20^{\circ}C$~$35^{\circ}C$)에서 맞추었으며 일장은 8.10.12.14로 처리했다. 3) 이를 요약하면 1) 단일 조건에서는 고온보다 저온에서 장일조건에서는 저온보다 고온에서 개화가 촉진되었다. ii) 대체로 고온 장일에서 보다는 저온 단일에서 다소 개화가 촉진 되었다. iii) 그러나 위와 가튼 경향은 품종간에 많은 차이를 볼 수 있다.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2000년도 춘계 학술대회지
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• pp.410-411
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• 2000

• 한국생명과학회:학술대회논문집
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• 한국생명과학회 2001년도 제31회 학술심포지움 및 춘계학술대회
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• pp.83-83
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• 2001