차광처리가 분화재배 섬기린초 ‘아틀란티스’의 생장과 엽색 품질에 미치는 영향

이재환,남상용 강원대학교 농업생명과학연구원 2022 강원 농업생명환경연구 Vol.34 No.3

Phedimus takesimensis is a succulent species indigenous to the Korean Peninsula and is found in Ulleungdo and Dokdo islands. It has potential medicinal properties; thus, it should be protected in South Korea. However, the optimal shading level for mass cultivation of P. takesimensis is unknown. In this study, we subjected P. takesimensis cv. Atlantis, a variegated leaf cultivar, to different shading levels (0, 35, 45, 60, 75, and 99%) and investigated its effect on the growth and leaf color of the plants. The results revealed that the potted plants grown under 45% shading exhibited the highest shoot length, width, and shoot fresh and dry weights. Moreover, the plants grown under 0-45% shading exhibited the highest root length and root fresh and dry weights. However, leaf length and width were higher in the plants grown under 35-60% shading, and the moisture content of the shoot and root was the highest in the plants grown under 60% and 75% shading, respectively. Chlorophyll content analysis revealed a subsequent increase as the shading level decreased; the L* and b* CIELAB values were higher as the shading levels increased. The CIE76 color difference (ΔE* ab) was the highest at 75% shading (ΔE* ab = 7.08) compared to that at 0% shading level. The plants that were grown under 0-45%, 60%, and 75% shading had the following RHS values: 147B and 148A; 147B and 148B; and 147C and 148B, respectively. This suggests that the leaves of the plants were relatively yellow at 60-75% shading. Thus, potted plants of P. takesimensis cv. Atlantis should be grown under 45% shading to attain a significant increase in plant size and improve leaf color.

Shade Avoidance and the Regulation of Leaf Inclination in Rice

Shin, Juhee,Park, Phun Bum Korean Society of Photoscience 2014 Rapid communication in photoscience Vol.3 No.3

The shade avoidance syndrome is a morphological and physiological response when plants are exposed to shade. Recent work in Arabidopsis had begun to define the molecular components of the shade avoidance syndrome in dicotyledonous model plant. However, little is known about the shade avoidance response networks in agriculturally important monocotyledon crops such as rice. Here, we found that the degree of bending at the lamina joint is inversely proportional to the R:FR ratio. To elucidate which phytochrome is involved in this response, we did lamina joint inclination assay with the rice phytochrome-deficient mutants (osphyA, osphyB, and osphyC) and the wild type plants. Whereas the osphyA and osphyC knockout mutants bent at the lamina joint in the far-red rich condition as the wild type plants, the osphyB knockout mutants no longer bent at the lamina joint in the far-red rich condition. These results suggest that PHYB acts as a sole photoreceptor in the lamina joint inclination response in rice.

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.

Photo-biotechnology as a tool to improve agronomic traits in crops

Gururani, Mayank Anand,Ganesan, Markkandan,Song, Pill-Soon Elsevier 2015 Biotechnology advances Vol.33 No.1

<P><B>Abstract</B></P> <P>Phytochromes are photosensory phosphoproteins with crucial roles in plant developmental responses to light. Functional studies of individual phytochromes have revealed their distinct roles in the plant's life cycle. Given the importance of phytochromes in key plant developmental processes, genetically manipulating phytochrome expression offers a promising approach to crop improvement. Photo-biotechnology refers to the transgenic expression of phytochrome transgenes or variants of such transgenes. Several studies have indicated that crop cultivars can be improved by modulating the expression of phytochrome genes. The improved traits include enhanced yield, improved grass quality, shade-tolerance, and stress resistance. In this review, we discuss the transgenic expression of phytochrome A and its hyperactive mutant (Ser599Ala-PhyA) in selected crops, such as <I>Zoysia japonica</I> (Japanese lawn grass), <I>Agrostis stolonifera</I> (creeping bentgrass), <I>Oryza sativa</I> (rice), <I>Solanum tuberosum</I> (potato), and <I>Ipomea batatas</I> (sweet potato). The transgenic expression of PhyA and its mutant in various plant species imparts biotechnologically useful traits. Here, we highlight recent advances in the field of photo-biotechnology and review the results of studies in which phytochromes or variants of phytochromes were transgenically expressed in various plant species. We conclude that photo-biotechnology offers an excellent platform for developing crops with improved properties.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Phytochromes are photoreceptors that are required for various developmental processes. </LI> <LI> Application of engineered phytochrome genes in various crops is discussed. </LI> <LI> Results with introduction of a mutant PHYA into turfgrasses and other crops are discussed. </LI> <LI> Potential areas for further improvement in photo-biotechnology are highlighted. </LI> </UL> </P>

잎의 발달단계의 leaf index를 조절하는 애기장대 MACROPHYLLA / ROTUNDIFOLIA3 유전자

전상은,투말라 찬드라쉐이커,조규형,이영병,형남인,남재성,김경태 한국식물생명공학회 2011 식물생명공학회지 Vol.38 No.4

In plants, heteroblasty reflects the morphological adaptation during leaf development according to the external environmental condition and affects the final shape and size of organ. Among parameters displaying heteroblasty, leaf index is an important and typical one to represent the shape and size of simple leaves. Leaf index factor is eventually determined by cell proliferation and cell expansion in leaf blades. Although several regulators and their mechanisms controlling the cell division and cell expansion in leaf development have been studied, it does not fully provide a blueprint of organ formation and morphogenesis during environmental changes. To investigate genes and their mechanisms controlling leaf index during leaf development,we carried out molecular-genetic and physiological experiments using an Arabidopsis mutant. In this study, we identified macrophylla (mac) which had enlarged leaves. In detail, the mac mutant showed alteration in leaf index and cell expansion in direction of width and length, resulting in not only modification of leaf shape but also disruption of heteroblasty. Molecular-genetic studies indicated that mac mutant had point mutation in ROTUDIFOLIA3 (ROT3) gene involved in brassinosteroid biosynthesis and was an allele of rot3-1 mutant. We named it mac/rot3-5 mutant. The expression of ROT3 gene was controlled by negative feedback inhibition by the treatment of brassinosteroid hormone,suggesting that ROT3 gene was involved in brassinosteroid biosynthesis. In dark condition, in addition, the expression of ROT3 gene was up-regulated and mac/rot3-5 mutant showed lower response, compare to wild type in petiole elongation. In plants, heteroblasty reflects the morphological adaptation during leaf development according to the external environmental condition and affects the final shape and size of organ. Among parameters displaying heteroblasty, leaf index is an important and typical one to represent the shape and size of simple leaves. Leaf index factor is eventually determined by cell proliferation and cell expansion in leaf blades. Although several regulators and their mechanisms controlling the cell division and cell expansion in leaf development have been studied, it does not fully provide a blueprint of organ formation and morphogenesis during environmental changes. To investigate genes and their mechanisms controlling leaf index during leaf development,we carried out molecular-genetic and physiological experiments using an Arabidopsis mutant. In this study, we identified macrophylla (mac) which had enlarged leaves. In detail, the mac mutant showed alteration in leaf index and cell expansion in direction of width and length, resulting in not only modification of leaf shape but also disruption of heteroblasty. Molecular-genetic studies indicated that mac mutant had point mutation in ROTUDIFOLIA3 (ROT3) gene involved in brassinosteroid biosynthesis and was an allele of rot3-1 mutant. We named it mac/rot3-5 mutant. The expression of ROT3 gene was controlled by negative feedback inhibition by the treatment of brassinosteroid hormone,suggesting that ROT3 gene was involved in brassinosteroid biosynthesis. In dark condition, in addition, the expression of ROT3 gene was up-regulated and mac/rot3-5 mutant showed lower response, compare to wild type in petiole elongation. This study suggests that ROT3 gene has an important role in control of leaf index during leaf expansion process for proper environmental adaptation, such as shade avoidance syndrome,via the control of brassinosteroid biosynthesis.

Structure and Function of the Phytochromes: Light Regulation of Plant Growth and Development

Park, Chung-Mo,Song, Pill-Soon Korean Society of Photoscience 2003 Journal of Photosciences Vol.10 No.1

Light exerts two primary roles in plant growth and development. Plants acquire all biochemical energy required for growth and propagation solely from light energy via photosynthesis. In addition, light serves as a medium through which plants recognize environmental fluctuations, such as photoperiod and presence of neighboring animals and plants. Plants therefore constantly monitor the direction, intensity, duration, and wavelength of environmental light and integrate these light signals into the intrinsic regulatory programs to achieve an optimized growth in a given light condition. Although light regulates all aspects of plant growth and developmental aspects, the molecular mechanisms and signaling cascades involved have not been well established until recently. However, recent advances in genetic tools and plant transformation techniques greatly facilitated the elucidation of molecular events in plant photomorphogenesis. This mini-review summarizes the gist of recent findings in deetiolation and suppression of shade avoidance response as classic examples of the phytochrome-mediated photomorphogenesis.

포플러의 Phytochrome B 유전자 분리 및 특성구명

강호덕 ( Ho Duck Kang ),이금영 ( Keum Young Lee ),강상구 ( Sang Gu Kang ),배한홍 ( Han Hong Bae ) 한국산림과학회 2005 한국산림과학회지 Vol.94 No.4

Morphological development and photosynthetic acclimation of Panax ginseng seedlings to irradiation by light-emitting diodes (LEDs)

장인배,도경란,Hyunseung Hwang,서수정,Jin Yu,장인복,문지원,Changhoo Chun 한국원예학회 2021 Horticulture, Environment, and Biotechnology Vol.62 No.4

To determine the optimal light intensity and enable plants to cope with various environmental stresses in plant factories, the morphological and photosynthetic characteristics of ginseng seedlings, including the secondary metabolites, were investigated under six light intensities: 25, 50, 75, 100, 125, and 150 μmol m−2 s−1. The shoot length increased with lower light intensity up to 75 μmol m−2 s−1, and the leaf area and specific leaf weight were greatest at 100 and 75 μmol m−2 s−1, respectively. Stomata frequency was higher from 100 μmol m−2 s−1 with higher light intensity, and single stomatal pore length also increased at 150 μmol m−2 s−1. Net photosynthetic rate at light saturation and net photosynthetic rate in growth condition increased sequentially up to 100 μmol m−2 s−1 before rapidly decreasing at 150 μmol m−2 s−1. The dark respiration rate and light compensation point were significantly high at 150 μmol m−2 s−1 only. Fv/Fm and chlorophyll content statistically differed from 63 and 84 days after seedling stand, respectively. Thus, the leaves withered to death with higher light intensity. The ginsenoside content in the roots significantly increased according to the light intensity, and the panaxadiol/panaxatriol (PT) ratio tended to decrease as the PT-type ginsenosides increased further. Taken together, the range of 75–100 μmol m−2 s−1 was found to be beneficial for growth, photosynthetic acclimation response, and total accumulated ginsenosides of ginseng seedlings.

Developmental Stage and Temperature Influence Elongation Response of Petiole to Low Irradiance in Cyclamen persicum

Wook Oh(오욱),Ki Sun Kim(김기선) 한국원예학회 2010 원예과학기술지 Vol.28 No.5

낮은 광도는 시클라멘(Cyclamen persicum Mill.)의 지상부 신장을 촉진하여 분화의 품질을 떨어뜨리는데, 그 정도는 발육단계와 환경요인에 따라 달라지는 것으로 보인다. 저광도에 대한 엽병의 신장 반응 양상을 알아보기 위해, 유년상(전개엽 5-6매), 전이상(화아 1-3개) 및 성년상(화경 신장 중인 화아 1-3개)의 ‘Metis Scarlet Red’ 시클라멘을 선별하여 명기/암기의 온도가 16/12(저온, LT), 22/18(중온, MT), 28/24℃ (고온, HT)로 유지되는 대형 생장상의 생장 모듈 내에서 생장시켰다. 생장 모듈은 명기 동안 두 가지 광도조건[60(저광, LL), 240(고광, HL) μ㏖ · m?² · s?¹ PPFD]으로 유지되었다. 실험 I에서는 MT 생장상에서 유년상의 식물체를 LL 또는 HL 모듈에 4주 동안 계속 두거나 처리 1, 2, 3주후 다른 광도의 모듈로 상호 이동시킨 후 신장 반응을 조사하였다. 실험Ⅱ에서는 MT 생장상에서, 유년상, 전이상, 그리고 성년상의 식물체를 LL 모듈에 넣은 지 0, 3, 6, 9, 12일째에 HL 모듈로 옮기고 21일째에 신장 반응을 조사하였다. 실험 Ⅲ에서는 LT, MT, HT 생장상에서 전이상의 식물체를 LL 모듈에 넣은 지 0, 3, 6, 9, 12일째에 HL 모듈로 옮기고 21일째에 신장 반응을 조사하였다. LL 노출시간이 0-4주까지 또는 0-12일까지 증가할수록 엽병장과 초장은 모든 온도 조건과 발육단계에서 증가하였다. 4주간 처리된 실험 Ⅰ에서 후기의 LL 노출이 전기의 노출보다 엽병의 신장속도를 증가시켰다. 실험 Ⅱ에서, 처리기간 12일 중 초기의 엽병 신장 양상을 보면 전이상 식물체가 유년상이나 성년상보다 LL에 더 민감하게 반응하였다. 실험 Ⅲ에서, 온도가 증가할수록, 그리고 LL노출시간이 길어질수록 시클라멘의 엽병장은 증가하였다. HT에서의 엽병 신장 속도는 LT와 비교하여 LL처리초기부터 빠르게 증가하였다. 엽병 신장에 있어서 온도 6℃ 증가는 3일간 LL 노출과 유사한 효과를 보였다. 결론적으로, 시클라멘은 전이상일 때 고온 하에서 더 즉각적으로 저광도에 반응하여 엽병을 신장시킨다는 것을 알 수 있었다. Reduced irradiance promotes shoot elongation depending on developmental stage and environmental factors and decreases plant quality in Cyclamen persicum Mill. To determine the petiole elongation responses to low irradiance, ‘Metis Scarlet Red’ cyclamen at different developmental stages [juvenile (5-6 unfolded leaves), transitional (1-3 visible flower buds), or mature (1-3 elongating peduncles)] was grown in growth modules at 60 (low light, LL) or 240 (high light, HL) μmol · m?² · s?¹ PPFD within the growth chambers at different temperatures [16/12 (low temperature, LT), 22/18 (medium temperature, MT), or 28/24℃ (high temperature, HT) (day/night)]. In Experiment I, juvenile plants were either kept in an LL or HL module during the entire treatment of 4 weeks or were transferred to the other module at 1, 2, or 3 weeks after treatment in an MT chamber. In Experiment Ⅱ, juvenile, transitional, or mature plants were moved to the HL module at 0, 3, 6, 9, or 12 days after being placed in the LL module at the MT chamber and grown for 21 days. In Experiment Ⅲ, transitional plants were moved to the HL module at 0, 3, 6, 9, or 12 days after being placed in the LL module at the LT, MT, or HT chambers. As the exposure duration to LL increased from 0 to 4 weeks or from 0 to 12 days, petiole length and plant height increased at all temperatures and developmental stages. In Experiment Ⅰ, the exposure to LL during the latter period, rather than the early period, increased elongation rate. In Experiment Ⅱ, petiole elongation in transitional plants was more sensitive to LL than juvenile or mature plants during the early period of the treatment for 12 days. In Experiment Ⅲ, petiole length increased with increasing temperature and exposure duration to LL. Petiole elongation rate at HT increased rapidly from the beginning of LL exposure as compared to LT. Increase of 6℃ in temperature had the similar effect to LL exposure for 3 days in petiole elongation. To conclude, transitional cyclamen under higher temperatures responds more immediately to low irradiance and elongates its petioles.

Growth and Flowering Responses of Petunia to Various Artificial Light Sources with Different Light Qualities

Park, In Sook,Cho, Kyung Jin,Kim, Jiseon,Cho, Ji Yoon,Lim, Tae Jo,Oh, Wook Korean Society of Horticultural Science 2016 원예과학기술지 Vol.34 No.1

This study was carried out to investigate the effect of artificial light sources with different light qualities on the growth and flowering characteristics of a herbaceous long-day plant, Petunia ${\times}$ hybrida Hort. Seedlings of petunia cultivar 'Madness Rose' were potted, acclimated for one week, and grown in a phytotron equipped with tube- and bulb-type fluorescent lamps (FL tube and bulb), tube-type white light-emitting diodes (LED tube), halogen lamps (HL), metal halide lamps (MH), and high pressure sodium lamps (HPS) for 10 weeks. The temperature, photoperiod, and photosynthetic photon flux density (PPFD) in the phytotron were $22{\pm}2^{\circ}C$, 16 h, and $25{\pm}2{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, respectively. Light sources combined with HL promoted stem elongation, and plant height and internode length decreased with increasing red to far-red (R:FR) ratio. FL tube + LED tube, HPS, and FL tube promoted branching, whereas plants grown under light sources combined with HL did not have any branches. Days to flowering (from longest to shortest) occurred as follows: FL tube + HL > FL tube + HL > MH > HPS = FL tube + FL bulb > FL tube + LED tube > LED tube > FL tube, indicating that reducing the R:FR ratio of the light sources promoted flowering. Only 20% of plants grown under an FL tube flowered, whereas under all other treatments, 100% of plants flowered. At 10 weeks after treatment, plants grown under HPS and MH had (cumulatively) 12 open flowers, and those grown under FL tube + FL bulb, LED tube, FL tube + LED tube, and HPS treatment had approximately seven flower buds. These results suggest that light sources with low R:FR ratios promote flowering and stem elongation in petunia, but they reduce its ornamental value due to overgrowth and poor branching.