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Author Chang, C., Chang, K., & Fu, W.
Title (up) Testing of Various Monochromatic LED Lights Used in Supplemental Irradiation of Lettuce in Modern urban Rooftop Polytunnels Type Journal Article
Year 2019 Publication Applied Engineering in Agriculture Abbreviated Journal
Volume Issue Pages
Keywords Plants
Abstract Urban farming could provide both vegetable growers and urban dwellers in general with more direct access to various fresh vegetables. Nevertheless, certain challenging problems associated with urban farming, including a lack of cultivation space and the effects of urban heat islands, must still be solved. Relatedly, a grower must, in some cases, also know how to utilize various forms of technology, such as lighting systems, as well as factors such as water availability. In this study, an original rooftop polytunnel design for lettuce (Lactuca sativa cv. Lollo Rosso) cultivation equipped with a hydroponic system and light emitting diodes (LEDs) is proposed. Various monochromatic lights were also tested for their effects on different quality parameters of lettuce. Specifically, supplemental red (655 nm), blue (445 nm), green (520 nm), and ultraviolet (380 nm) LED lights were used at night to apply photon fluxes of 150, 150, 150, and 20 μmol.m-2.s-1, respectively. The resulting effects of these different colored LEDs on the pigment concentration and growth response of the lettuce grown inside the roof polytunnel were then investigated. The experiment was then repeated several times with different environmental parameters in order to compare the effects of the different light wavelengths under higher temperatures and higher natural irradiation conditions.The results indicated that supplemental red or blue light at night could be strategically employed to maintain low nitrate levels and enhance the nutritional value and growth of lettuce grown in roof polytunnels.
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Call Number IDA @ intern @ Serial 2349
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Author Joo, Y.; Fragoso, V.; Yon, F.; Baldwin, I.T.; Kim, S.-G.
Title (up) The circadian clock component, LHY, tells a plant when to respond photosynthetically to light in nature Type Journal Article
Year 2017 Publication Journal of Integrative Plant Biology Abbreviated Journal J Integr Plant Biol
Volume 59 Issue 8 Pages 572-587
Keywords plants
Abstract The circadian clock is known to increase plant growth and fitness, and thought to prepare plants for photosynthesis at dawn and dusk; whether this happens in nature was unknown. We transformed the native tobacco, Nicotiana attenuata to silence two core clock components, NaLHY (irLHY) and NaTOC1 (irTOC1). We characterized growth and light-and dark-adapted photosynthetic rates (Ac ) throughout a 24 h day in empty vector-transformed (EV), irLHY, and irTOC1 plants in the field, and in NaPhyA-and NaPhyB1-silenced plants in the glasshouse. The growth rates of irLHY plants were lower than those of EV plants in the field. While irLHY plants reduced Ac earlier at dusk, no differences between irLHY and EV plants were observed at dawn in the field. irLHY, but not EV plants, responded to light in the night by rapidly increasing Ac . Under controlled conditions, EV plants rapidly increased Ac in the day compared to dark-adapted plants at night; irLHY plants lost these time-dependent responses. The role of NaLHY in gating photosynthesis is independent of the light-dependent reactions and red light perceived by NaPhyA, but not NaPhyB1. In summary, the circadian clock allows plants not to respond photosynthetically to light at night by anticipating and gating red light-mediated in native tobacco.
Address Department of Molecular Ecology, Max Planck Institute for Chemical Ecology, Hans-Knoll-Str. 8, D-07745, Jena, Germany
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Language English Summary Language Original Title
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ISSN 1672-9072 ISBN Medium
Area Expedition Conference
Notes PMID:28429400 Approved no
Call Number LoNNe @ kyba @ Serial 1657
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Author Taylor, G.; Davies, W.J.
Title (up) The Control Of Leaf Growth Of Betula And Acer By Photoenvironment Type Journal Article
Year 1985 Publication New Phytologist Abbreviated Journal New Phytol
Volume 101 Issue 2 Pages 259-268
Keywords Plants
Abstract Leaf extension of one‐year‐old seedlings of silver birch (Betula pendula Roth.) and sycamore (Acer pseudoplatanus L.), was measured using linear variable transducers (LVDTs) interfaced to a microcomputer. Birch and sycamore seedlings exhibited contrasting patterns of leaf extension during a diurnal cycle with a 16 h photoperiod. Birch leaves grew more rapidly when illuminated; growth during the photoperiod was approximately doubled when compared with growth in the dark. Mean relative growth rates ±SE at ‘lights‐on + 3 h’ and ‘lights‐off + 5 h’ were 0.0136 ± 0.0016 and 0.0066 ± 0.0005 h−1 respectively. In direct contrast, growth of sycamore leaves was increased when leaves were darkened; mean relative growth rates + SE at ‘lights‐on+3 h’ and ‘lights‐off + 5 h’ were 0.0056 ± 0.0005 and 0.0094 ± 0.0008 h‐1 respectively.

When leaves of birch and sycamore were darkened, increased leaf turgor was measured in both species, but only in sycamore was this higher night‐time turgor associated with a higher rate of leaf growth.

Cell wall extensibility (WEX), an indication of the ability of cell walls to loosen and extend irreversibly, and cell surface pH were assessed in darkened and illuminated leaves of both species. An increase in WEX was measured when birch leaves were illuminated (P≤ 0.001) and this was accompanied by a decline in cell surface pH (P≤ 0.001). However, when leaves of sycamore were illuminated, WEX declined (P≤ 005) and cell surface pH increased (P≤ 0.001).

The ability of these species to survive beneath a woodland canopy is discussed in relation to the cellular factors controlling their leaf growth.
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Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0028-646X ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number GFZ @ kyba @ Serial 1992
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Author Chaves, I.; Pokorny, R.; Byrdin, M.; Hoang, N.; Ritz, T.; Brettel, K.; Essen, L.-O.; van der Horst, G.T.J.; Batschauer, A.; Ahmad, M.
Title (up) The cryptochromes: blue light photoreceptors in plants and animals Type Journal Article
Year 2011 Publication Annual Review of Plant Biology Abbreviated Journal Annu Rev Plant Biol
Volume 62 Issue Pages 335-364
Keywords Adenosine Triphosphate/metabolism; Animals; Cryptochromes/chemistry/classification/*physiology; DNA Repair; Deoxyribodipyrimidine Photo-Lyase/chemistry/classification/physiology; Homing Behavior; Insects/physiology; *Light Signal Transduction; Magnetics; Mice; Oxidation-Reduction; Phosphorylation/physiology; Plants/*metabolism; blue light
Abstract Cryptochromes are flavoprotein photoreceptors first identified in Arabidopsis thaliana, where they play key roles in growth and development. Subsequently identified in prokaryotes, archaea, and many eukaryotes, cryptochromes function in the animal circadian clock and are proposed as magnetoreceptors in migratory birds. Cryptochromes are closely structurally related to photolyases, evolutionarily ancient flavoproteins that catalyze light-dependent DNA repair. Here, we review the structural, photochemical, and molecular properties of cry-DASH, plant, and animal cryptochromes in relation to biological signaling mechanisms and uncover common features that may contribute to better understanding the function of cryptochromes in diverse systems including in man.
Address Department of Genetics, Erasmus University Medical Center, 3000 CA Rotterdam, The Netherlands. i.chaves@erasmusmc.nl
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Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1543-5008 ISBN Medium
Area Expedition Conference
Notes PMID:21526969 Approved no
Call Number IDA @ john @ Serial 341
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Author Caffarra, A.; Donnelly, A.
Title (up) The ecological significance of phenology in four different tree species: effects of light and temperature on bud burst Type Journal Article
Year 2011 Publication International Journal of Biometeorology Abbreviated Journal Int J Biometeorol
Volume 55 Issue 5 Pages 711-721
Keywords Plants
Abstract The process of adaptation is the result of stabilising selection caused by two opposite forces: protection against an unfavourable season (survival adaptation), and effective use of growing resources (capacity adaptation). As plant species have evolved different life strategies based on different trade offs between survival and capacity adaptations, different phenological responses are also expected among species. The aim of this study was to compare budburst responses of two opportunistic species (Betula pubescens, and Salix x smithiana) with that of two long-lived, late successional species (Fagus sylvatica and Tilia cordata) and consider their ecological significance. Thus, we performed a series of experiments whereby temperature and photoperiod were manipulated during dormancy. T. cordata and F. sylvatica showed low rates of budburst, high chilling requirements and responsiveness to light intensity, while B. pubescens and S. x smithiana had high rates of budburst, low chilling requirements and were not affected by light intensity. In addition, budburst in B. pubescens and S. x smithiana was more responsive to high forcing temperatures than in T. cordata and F. sylvatica. These results suggest that the timing of growth onset in B. pubescens and S. x smithiana (opportunistic) is regulated through a less conservative mechanism than in T. cordata and F. sylvatica (long-lived, late successional), and that these species trade a higher risk of frost damage for the opportunity of vigorous growth at the beginning of spring, before canopy closure. This information should be considered when assessing the impacts of climate change on vegetation or developing phenological models.
Address Department of Botany, School of Natural Sciences, Trinity College Dublin, Ireland. amelia.caffarra@gmail.com
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Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0020-7128 ISBN Medium
Area Expedition Conference
Notes PMID:21113629 Approved no
Call Number LoNNe @ kyba @ Serial 1675
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