Photoreversibility of Fruiting and Growth in Oriental Melon (Cucumis melo L.)

( Sung-chang Hong ),( Jin-ho Kim ),( So-jin Yeob ),( Min-wook Kim ),( Sae-nun Song ),( Gyu-hyun Lee ),( Kyeong-sik Kim ),( Seon-young Yu ) 한국환경농학회 2020 한국환경농학회지 Vol.39 No.4

BACKGROUND: Photoreversibility, a reversion of the inductive effect of a brief red light pulse by a subsequent far red light pulse, is a property of photo responses regulated by the plant photoreceptor phytochrome B. Plants use photoreceptors to sense photo signal and to adapt and modify their morphological and physiological properties. Phytochrome recognizes red light and far red light and plays an important role in regulating plant growth and development. METHODS AND RESULTS: The reversal responses of growth and fruiting characteristics were investigated to increase the yield of oriental melon (Cucumis Melo L. var. Kumsargakieuncheon) by means of controlling light quality in a plastic house. Red (R:660nm) and far red (FR:730nm) lights were subsequently irradiated on the whole stems and leaves of the oriental melon plant during growing periods, using red and far red LEDs as light sources, from 9:00 PM daily for 15 minutes. The intensities of R and FR light were 0.322-0.430 μmol m^-2s^-1 and 0.250-0.366 μmol m^-2s^-1, respectively. Compared to R light irradiation, combination of R and FR light irradiation increased the length of internode, number of axillary stems, number of female flowers, and fruit number of oriental melons. The results of treatment with R were similar to R-FR-R light irradiation in terms of length of internode, number of axillary stems, number of female flowers, and number of fruits. When FR treatment was considered, R-FR and R-FR-R-FR light irradiation had similarities in responses. These reversal responses revealed that oriental melon showed a photoreversibility of growth characteristics, flowering, and fruiting. CONCLUSION: These results suggested the possibility of phytochrome regulation of female flower formation and fruiting in oriental melon. The fruit weight of the oriental melon was the heaviest with the R light irradiation, while the number of fruits was the highest with the FR light. With the FR light irradiation, the fruit weight was not significantly higher compared to that of the control. Meanwhile, the yield of oriental melon fruits increased by 28-36% according to the intensities of the FR light due to the increases of the number of fruits.

Spectral Properties of Sunlight and Phytochrome Photoequilibrium as Influenced by Leaf Number in Chrysanthemum

Byung-Joo Lee,Mi-Kyoung Won,Taeg-Young Choi,Ki-Woo Kim,Jong Suk Lee 한국원예학회 2005 Horticulture, Environment, and Biotechnology Vol.46 No.2

As the incident sunlight passes through plant leaves, the amount of light is reduced due to the absorption and reflection by leaves. There are also qualitative changes in transmitted light. The present work examined light intensity, spectral quality transmitted, and phytochrome photoequilibrium as influenced by the number of leaf in chrysanthemum (Dendranthema grandiflorum). The photon flux of incident sunlight increased rapidly from 300 to 500 ㎚ and remained relatively constant above these wavelengths and had approximately equal photon flux of red and far-red lights. As the number of leaf increased, photon flux in 300?800 ㎚ range decreased rapidly but photosynthetically active radiation in 400?700 ㎚ range attenuated more rapidly from 3.0 to < 0.1%. There were also changes in light composition. Most of sunlight in the red and blue regions decreased more rapidly than green and UV regions. The rapid attenuation of blue and red lights was attributed to the absorption by chlorophylls, because red and blue regions are absorbed more effectively than other lights. The light transmitted by leaves was predominantly far-red light and as a result, the red/far-red ratio decreased. Such results led to changes in the phytochrome photoequilibrium. Phytochrome photoequilibrium of incident sunlight was 0.72, but it decreased to 0.26, 0.12, and 0.09 with the increasing leaf number. These results show that light environment and phytochrome photoequilibrium change as leaf number changes, and these changes may control photosynthetic and morphological characteristics in a plant or plant populations of chrysanthemum

Effect of far-red light on the production and diversity of ginsenosides in leaves of Panax ginseng Meyer

Mohanan Padmanaban,Yang Tae-Jin,Song Young Hun 한국응용생명화학회 2023 Applied Biological Chemistry (Appl Biol Chem) Vol.66 No.-

Ginsenosides are the most valuable and pharmacologically active triterpenoid saponins found in Panax ginseng. Although light quality affects ginsenoside content, little is known about the underlying genetic and regulatory mechanisms. Additionally, the correlation between the adaptability of ginseng to shade and ginsenoside biosynthesis remains poorly understood. In the present study, transcriptome analysis of ginseng seedlings using RNA sequencing revealed that the expression of ginsenoside biosynthesis genes, including PgHMGR, PgFPS, PgSS, and PgUGT, was enhanced in shade conditions but downregulated by red light, indicating that far-red light might play an essential role in ginsenoside production. Further, gene expression analysis in adventitious roots and 2-year-old plants using qRT-PCR showed that the light quality-mediated expression patterns of ginsenoside genes varied with tissue and age. However, unlike the transcriptome, there was no difference in the total ginsenoside content in seedlings among various light conditions. Nevertheless, the amount of major protopanaxadiol-type ginsenosides increased under shade and red light conditions. Unlike seedlings and adventitious roots, there was a decrease in the expression of PgHMGR, PgFPS, PgSS, and PgDDS in 2-year-old plants, along with an increase in the ginsenoside content, under far-red light. Taken together, our findings suggest that far-red light is an important environmental factor for ginsenoside biosynthesis and diversification and provide information that can improve the quality of ginseng produced for medicinal purposes.

고품질의 토마토 생산을 위한 광처리 기술개발 -일몰 후 광처리가 토마토묘 소질에 미치는 영향-

이귀현 (사) 한국생물환경조절학회 2001 시설원예‧식물공장 Vol.10 No.1

To investigate the effect of red light (R) and far-red light (FR) on controlling the growth of tomatotransplants, height, length of 1st internode, and stem diameter of plant were measured every 12 daysduring 24 days of light treatment. At the end of experiment, fresh and dry weights of roots and shootswere measured. Generally, it was shown that the height of plant was suppressed by the treatment of Rand was enhanced by the treatment of FR. However, the effect of light-treatment time (10 or 20 min)on plant height was not significant. Stem diameter of the plant treated with R was greater than that ofthe plant treated with FR or the control. Dry weight ratio of shoot to rot of the plant treated with Rwas smaller than that of the plant treated with FR. R was more effective than the control, which wasmore effective than FR, in making the transplant compact.

Subcellular partitioning-dependent functional switching of Arabidopsis photoreceptor phytochrome B in response to brassinosteroids

Ryu, Jong-Sang,Choi, Hyun-Mo,Hong, Sung-Hyun,Matsushita, Tomonao,Nagatani, Akira,Nam, Hong-Gil Korean Society for Bioinformatics 2009 Interdisciplinary Bio Central (IBC) Vol.1 No.1

Many organisms control their physiology and behavior in response to the local light environment, which is first perceived by photoreceptors that undergo light-dependent conformational changes. Phytochromes are one of the major photoreceptors in plants, controlling wide aspects of plant physiology by recognizing the light in red (R) and far-red (FR) spectra. Higher plants have two types of phytochromes; the photo-labile type I (phyA in Arabidopsis) and photo-stable type II (phyB-E in Arabidopsis). Phytochrome B (phyB), a member of the type II phytochromes in Arabidopsis, shows classical R and FR reversibility between the inter-convertible photoisomers, Pr and Pfr. Interestingly, the Pr and Pfr isomers show partitioning in the cytosol and nucleus, respectively. In the over 50 years since its discovery, it has been thought that the type II phytochromes only function to mediate R light. As described in the text, we have now discovered phyB has an active function in FR light. Even striking is that the R and FR light exert an opposite effect. Thus, FR light is not simply nullifying the R effect but has an opposing effect to R light. What is more interesting is that the phyB-mediated actions of FR and R light occur at different cellular compartment of the plant cell, cytosol and nucleus, respectively, which was proven through utilization of the cytosolic and nuclear-localized mutant versions of phyB. Our observations thus shoot down a major dogma in plant physiology and will be considered highly provocative in phytochrome function. We argue that it would make much more sense that plants utilize the two isoforms rather than only one form, to effectively monitor the changing environmental light information and to incorporate the information into their developmental programs.

Evaluation of Growth, Flowering, and Chlorophyll Fluorescence Responses of Viola cornuta cv. Penny Red Wing according to Spectral Power Distributions

장인태,이재환,신은지,남상용 인간식물환경학회 2023 인간식물환경학회지 Vol.26 No.4

Background and objective: The genus Viola, a member of the Violaceae family, is renowned for its ornamental flower crops. Additionally, Viola species are relatively pest-resistant and easy to manage. They are widely used in gardens, and some oftheir flowers are even edible. In this study, our focus was on V. cornuta cv. Penny Red Wing (hereinafter referred to as‘Penny Red Wing’), an experimental plant chosen for its high ornamental value and rapid growth. Methods: We applied a purple light-emitting diode (LED) and three types of white LEDs with varying color temperatures:3000, 4100, and 6500 K, respectively, as artificial light sources. Notably, a purple LED has a far-red wavelength (700-800nm) ratio of approximately 17.6% in their spectral power distribution. Results: The findings indicated that several parameters exhibited higher values under purple LED: shoot size parameters,shoot biomass, moisture content of shoots and roots, photochemical reflectance index (PRI), modified chlorophyllabsorption ratio index (MCARI), total number of flowers, flower size parameters, scent score, Fv/Fm, and PIABS. However,the 6500 K white LED led to higher evaluations of root length, number of shoots and leaves, root biomass, moisture contentof shoots and roots, Fv/Fm, and PIABS. Nevertheless, it was observed that shoot growth was relatively hindered, and theflowering responses were inadequate under the 6500 K white LED, suggesting their unsuitability for the mass productionof ‘Penny Red Wing’. Furthermore, the 3000 and 4100 K white LEDs were also deemed unsuitable for cultivating ‘PennyRed Wing’ due to their lower cultivation efficiency. Conclusion: ‘Penny Red Wing’ was evaluated as having superior growth, flowering, and chlorophyll fluorescence responsesunder purple LED, indicating that the far-red wavelength had a more pronounced effect compared to the green wavelength(500-600 nm). Therefore, we recommend cultivating this cultivar under purple LED, which include the far-red wavelength.

Supplemental Irradiation with Far-red Light-emitting Diodes Improves Growth and Phenolic Contents in Crepidiastrum denticulatum in a Plant Factory with Artificial Lighting

배지훈,오명민,박송이 한국원예학회 2017 Horticulture, Environment, and Biotechnology Vol.58 No.4

The aim of this study was to analyze the growth and phytochemical composition of Crepidiastrum denticulatum,a valuable medicinal plant, in response to various periods of irradiation and ratios of far-red (FR) LED light combinedwith red (R) and blue (B) LED lights. Three-week-old C. denticulatum seedlings were transplanted to a hydroponicsystem in a plant factory equipped with R, B, and FR LEDs. The ratio of R to B LEDs was set at 8:2 (R8B2), andthe ratio of R to FR LEDs was adjusted to 0.7, 1.2, 4.1, and 8.6. R8B2 (without FR LEDs) and commercial LEDswere used as control I and II, respectively. The plants were cultivated under these light treatments, and some of thecontrol plants were subjected to four different R/FR ratios for 30 min before the end of the light period (EOL). Wemeasured growth characteristics, total phenolic contents, and the levels of individual phenolic compounds (chlorogenicacid, caffeic acid, and chicoric acid) 6 weeks after treatment. Shoot fresh and dry weight, leaf area, leaf length, andleaf width under R/FR ratios of 0.7 and 1.2 were 1.8- to 2.4-times higher than those of the control plants. ContinuousR/FR 0.7 and 1.2 irradiation reduced the total phenolic content per dry weight compared to the control, although thiseffect was not significant. The total phenolic content per plant under R/FR 0.7 and 1.2 increased more than 2-fold, andthe shoot fresh weight increased 1.7- and 1.6-fold, compared to control I. Individual phenolic compound levels exhibitedthe same trends as total phenolic content. Under R/FR 0.7 and 1.2, chlorogenic acid, caffeic acid, and chicoric acidlevels per shoot increased 1.3- to 1.8-fold compared to control I. FR EOL treatments did not have a significant effectson growth or the contents of bioactive compounds. These results suggest that supplemental irradiation with FR LEDscould be used to improve C. denticulatum growth and quality in terms of phytochemical composition when grown ina plant factory with artificial lighting.

Competition Responses of Populus alba Clone ‘Bolleana’ to red:far-red light

Bae,Han-hong,Kang,Ho-duck,Richard B,Hall 한국자원식물학회 2004 Plant Resources Vol.7 No.1

The reduced ratio of red:far-red (R:FR) light acts as a measure of the proximity of competitors and plants can detect the potentially competing neighbor plants by perceiving reflected R:FR signals and initiate the response of “shade avoidance” before actual shading occurs. The phytochrome system is responsible for monitoring the changes in the R:FR and initiating the shade avoidance response. The response to low R:FR ratio was studied in a white aspen Populus alba clone ‘Bolleana’ using two filter systems: a clear plastic filter system that allows a R:FR ratio less than 1.0 to pass from adjacent border plant reflection; and a special commercial plastic that blocks FR light and creates a R:FR ratio above 3.0. The reduced R:FR signals enhanced the stem elongation in response to competition at the expense of relative stem diameter growth. Trees grown inside clear chambers were 27 % taller than trees grown inside the FR-blocking filter chambers. Stem taper of clear chamber trees was 16% less than the FR-blocking filter trees. Low R:FR also induced 22% more stem dry weight and 13% greater petiole length per leaf compared to the FR-blocking filter trees. There were no statistically significant differences in leaf area, leaf number increment, and total dry weight between the two light filter treatments.

고압나트륨 및 플라즈마 램프 보광이 절화 장미의 품질 및 수량에 미치는 영향

이민정(Min Jung Lee),서효숙(Hyo Sook Seo),민상윤(Sang Yoon Min),이진희(Jinhee Lee),박수현(Suhyun Park),전정빈(Jeong Bin Jeon),김지선(Jiseon Kim),오욱(Wook Oh) 한국원예학회 2021 원예과학기술지 Vol.39 No.1

이 연구는 절화 장미의 동계 보광 재배 시 새롭게 개발된 플라즈마(PLS) 램프와 관행의고압나트륨(HPS)이 장미의 생육 특성, 수량 및 품질에 미치는 효과를 비교하기 위해 실시되었다. 이를 위해 경북 경산시 소재 플라스틱하우스에서 스탠다드 장미(Rosa hybrida) ‘Aqua’와 ‘Brut’를 대상으로 10월 10일부터 이듬해 3월 23일까지 PPFD 120μmol·m<SUP>-2</SUP>·s<SUP>-1</SUP>의 HPS와 PLS로 14시간(17:00부터 익일 07:00) 동안 보광을 실시하였고, 대조구는 광주기의 효과를 상쇄하기 위해 이미 온실에 설치되어 있었던 HPS (10μmol·m<SUP>-2</SUP>·s<SUP>-1</SUP>)로 같은 시간 동안 점등하였다. 절화 수확은 12월부터 3월까지 주당 2회 수행되었고, 생장 및 개화 특성, 절화 특성, 절화 수확량 및 절화 등급별 수확량을 조사하였다. 광원 특성에 있어서는 PLS가 HPS보다 청색광(B)이 많은 반면 적색광(R)과 근적외선(NIR)이 적었으며, 녹색광(G)과 원적색광(FR)은 비슷한 수준이었다. 이로 인해 PLS의 B:R은 PLS보다 더 높고, R:FR은 더 낮았다. 보광 효과에 있어서는 PLS 및 HPS 보광처리구에서 대조구보다 ‘Aqua’ 및 ‘Brut’의 거의 모든 특성이 향상되었다. 특히, ‘Aqua’에 있어서 PLS 보광처리구에서 절화장, 화고, 생체중, 건물중, 절화수명, 상등품 수량 등이 HPS 처리구보다 높은 수치를 나타내었다. 이러한 차이는 PLS의 상대적으로 낮은 R:FR이 절화장과 엽면적을 증가시켰고 이로 인해 광합성의 증가로 수량 및 품질 향상과 작기 단축이 가능했으며, 상대적으로 높은 높은 B:R도 기공 열기를 통해 가스교환을 촉진하여 광합성을 증대시켰기 때문에 생겼을 것으로 생각된다. 다만, ‘Brut’에서는 PLS의 효과가 크게 나타나지 않아 PLS의 보광 효과에 품종 간 차이가 있을 것으로 보인다. Used as supplemental lighting (SL) in protected flower growing systems, newly developed sulfur plasma lamps (PLS) may confer benefits in terms of growth, yield, and quality. This study compared the effects of SL with PLS versus conventional high-pressure sodium lamps (HPS) on the growth characteristics, yield, and quality of cut roses cultivated in winter. Between October 10, 2016 and March 23, 2017, standard cut rose (Rosa hybrida) cultivars ‘Aqua’ and ‘Brut’ were grown under PLS and HPS with a photosynthetic photon flux density (PPFD) of 120 μmol·m<SUP>-2</SUP>·s<SUP>-1</SUP> for 14 hours (between 17:00 and 07:00). Rose plants were cultivated in a plastic greenhouse in Gyeongsan, Gyeongsangbuk-do. A control condition used HPS with PPFD at 10 μmol·m<SUP>-2</SUP>·s<SUP>-1</SUP> to offset the effect of the photoperiod. Cut flowers were harvested twice a week from December to March, and their growth and flowering characteristics, yield and quality of cut flowers were measured at each harvest. PLS had more blue (B) light and less red (R) light and near-infrared light than HPS; green and far-red light (FR) levels were similar. Plants under SL with PLS therefore received a higher B:R ratio and lower R:FR ratio than those under HPS. SL with PLS and HPS improved almost all of the characteristics of ‘Aqua’ and ‘Brut’ compared with the control. In particular, SL with PLS in ‘Aqua’ increased cut flower length, fresh and dry weights, vase life, and the number of higher grade products than SL with HPS. These differences could be associated with the relatively low R:FR ratio of PLS, which may have increased stem length and leaf area, thus increasing photosynthesis and resulting in higher yield and quality of cut flowers, as well as a shorter crop period. Likewise, the relatively high B:R ratio of PLS may have promoted gas exchange through stomatal opening and increased photosynthesis, resulting in higher yield and quality. However, the effect of light source for SL on morphological characteristics such as leaf area and stem length may be somewhat cultivar-dependent because the effect of SL with PLS in ‘Brut’ was smaller than that in ‘Aqua’.

Artificial Light Sources Affect Flower Initiation of Chrysanthemum in Relation to Phytochrome Photoequilibrium

Byung-Joo Lee,Mi-Kyoung Won,Taeg-Yong Choi,Euy-Seog Yang,Jong Suk Lee 한국원예학회 2005 Horticulture, Environment, and Biotechnology Vol.46 No.2

The effect of artificial light sources on flower initiation of chrysanthemum (Dendranthema grandiflorum cv. Puma) was examined. The plants were grown until an autonomous flower bud (crown bud) stage in long photoperiods by interrupting the nights with either incandescent, fluorescent, metal halide, or high-pressure sodium lamps. Flower bud initiation advanced and long-day leaf number decreased in high-pressure sodium lamps followed by metal halide, fluorescent, and incandescent lamps. The advancement of flower initiation and decrease of longday leaf number under the fluorescent long-day treatment as compared to the incandescent long-day treatment were attributed to the high red/far-red ratio (6.43) and phytochrome photoequilibrium (?) value (0.84) of the fluorescent lamp. On the other hand, fluorescent, metal halide, and high-pressure sodium lamps had similar levels of ? (0.83 ± 0.01) and blue plus red light composition, but their light intensities varied from 7.3 to 160.6 μ㏖ㆍm?²ㆍs?¹. Therefore, the primary reason for the advanced time to flower initiation under metal halide and high-pressure sodium lamp treatment should be the photon flux density rather than the differences of phytochrome photoequilibrium and spectral distribution.