scholarly journals Effects of light intensity and light quality on growth and circadian rhythm of saxitoxins production in Cylindrospermopsis raciborskii (Cyanobacteria)

2009 ◽  
Vol 31 (5) ◽  
pp. 481-488 ◽  
Author(s):  
R. L. Carneiro ◽  
M. E. V. dos Santos ◽  
A. B. F. Pacheco ◽  
S. M. F. d. O. e Azevedo
Keyword(s):  
Circadian Rhythm ◽  
Light Intensity ◽  
Light Quality ◽  
Cylindrospermopsis Raciborskii

scholarly journals Effects of light intensity and temperature on Cylindrospermopsis raciborskii (Cyanobacteria) with straight and coiled trichomes: growth rate and morphology

2012 ◽  
Vol 72 (2) ◽  
pp. 343-351 ◽  
Author(s):  
MC. Bittencourt-Oliveira ◽  
B. Buch ◽  
TC. Hereman ◽  
JDT. Arruda-Neto ◽  
AN. Moura ◽  
...  
Keyword(s):  
Growth Rate ◽  
Light Intensity ◽  
Morphological Changes ◽  
Population Control ◽  
Distinct Species ◽  
Cylindrospermopsis Raciborskii ◽  
Climatic Chamber ◽  
Light Intensities ◽  
Different Temperatures ◽  
Lower Temperature

Cylindrospermopsis raciborskii (Woloszynska) Seenayya et Subba Raju (Ordem Nostocales) is one of the most troublesome bloom-forming species in Brazil. Understanding the population dynamics of the different morphotypes of C. raciborskii (straight and coiled) could assist in the prediction of favourable conditions for the proliferation of this potentially toxin-producing species. The aim of the present study was to assess the effects of two different light intensities and temperatures on the growth rate and morphology of the trichomes of the straight and coiled morphotypes. For such, two non-toxin producing strains of C. raciborskii were used - one with a coiled trichome (ITEP31) and another with a straight trichome (ITEP28). The strains were cultured in BG-11 medium in a climatic chamber under controlled conditions. Two light intensities (30 and 90 µmol.m-2.s-1 ) were combined at temperatures of 21 and 31 °C and the growth rate and morphological changes were analysed. The morphotypes responded differently to the different temperatures and light intensities. Both strains exhibited faster growth velocities when submitted to higher light intensity and temperature. The lower temperature and higher luminosity hampered the development of both strains. Variations in cellular morphology and an absence of akinetes in both strains were related to the lower temperature (21 °C). The coiled morphotype demonstrated considerable phenotype plasticity, changing the morphology of trichome throughout its growth curve. Although molecular analysis does not sustain the separation of the morphotypes as distinct species, their different eco-physiological responses should be considered further knowledge of extreme importance for the population control of these potentially toxic organisms.

Effects of Different Light Intensity and Light Quality on Adventitious Buds Induction and Growth of Clematis‘nelly moser’

2013 ◽  
Vol 42 (6) ◽  
pp. 715-720
Author(s):  
徐玲玲 XU Ling-ling ◽  
丁朵朵 DING Duo-duo ◽  
陶贵荣 TAO Gui-rong ◽  
党悦方 DANG Yue-fang ◽  
郭斌 GUO Bin
Keyword(s):  
Light Intensity ◽  
Light Quality ◽  
Adventitious Buds

scholarly journals Temperature and Light-Quality-Dependent Regulation of Freezing Tolerance in Barley

Plants ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 83 ◽  
Author(s):  
Mohamed Ahres ◽  
Krisztián Gierczik ◽  
Ákos Boldizsár ◽  
Pavel Vítámvás ◽  
Gábor Galiba
Keyword(s):  
Light Intensity ◽  
Target Gene ◽  
Light Quality ◽  
Incident Light ◽  
Gene Expression Pattern ◽  
Frost Tolerance ◽  
Light Conditions ◽  
Incident Light Intensity ◽  
Binding Factor ◽  
R:Fr Ratio

It is established that, besides the cold, incident light also has a crucial role in the cold acclimation process. To elucidate the interaction between these two external hardening factors, barley plantlets were grown under different light conditions with low, normal, and high light intensities at 5 and 15 °C. The expression of the HvCBF14 gene and two well-characterized members of the C-repeat binding factor (CBF)-regulon HvCOR14b and HvDHN5 were studied. In general, the expression level of the studied genes was several fold higher at 5 °C than that at 15 °C independently of the applied light intensity or the spectra. The complementary far-red (FR) illumination induced the expression of HvCBF14 and also its target gene HvCOR14b at both temperatures. However, this supplementation did not affect significantly the expression of HvDHN5. To test the physiological effects of these changes in environmental conditions, freezing tests were also performed. In all the cases, we found that the reduced R:FR ratio increased the frost tolerance of barley at every incident light intensity. These results show that the combined effects of cold, light intensity, and the modification of the R:FR light ratio can greatly influence the gene expression pattern of the plants, which can result in increased plant frost tolerance.

scholarly journals Light-responsive expression atlas reveals the effects of light quality and intensity in Kalanchoë fedtschenkoi, a plant with crassulacean acid metabolism

GigaScience ◽  
2020 ◽  
Vol 9 (3) ◽  
Author(s):  
Jin Zhang ◽  
Rongbin Hu ◽  
Avinash Sreedasyam ◽  
Travis M Garcia ◽  
Anna Lipzen ◽  
...  
Keyword(s):  
Light Intensity ◽  
White Light ◽  
Crassulacean Acid Metabolism ◽  
Light Quality ◽  
Acid Metabolism ◽  
Easy Access ◽  
Cam Plants ◽  
A Genome ◽  
Acid Accumulation ◽  
Expression Atlas

Abstract Background Crassulacean acid metabolism (CAM), a specialized mode of photosynthesis, enables plant adaptation to water-limited environments and improves photosynthetic efficiency via an inorganic carbon-concentrating mechanism. Kalanchoë fedtschenkoi is an obligate CAM model featuring a relatively small genome and easy stable transformation. However, the molecular responses to light quality and intensity in CAM plants remain understudied. Results Here we present a genome-wide expression atlas of K. fedtschenkoi plants grown under 12 h/12 h photoperiod with different light quality (blue, red, far-red, white light) and intensity (0, 150, 440, and 1,000 μmol m–2 s–1) based on RNA sequencing performed for mature leaf samples collected at dawn (2 h before the light period) and dusk (2 h before the dark period). An eFP web browser was created for easy access of the gene expression data. Based on the expression atlas, we constructed a light-responsive co-expression network to reveal the potential regulatory relationships in K. fedtschenkoi. Measurements of leaf titratable acidity, soluble sugar, and starch turnover provided metabolic indicators of the magnitude of CAM under the different light treatments and were used to provide biological context for the expression dataset. Furthermore, CAM-related subnetworks were highlighted to showcase genes relevant to CAM pathway, circadian clock, and stomatal movement. In comparison with white light, monochrome blue/red/far-red light treatments repressed the expression of several CAM-related genes at dusk, along with a major reduction in acid accumulation. Increasing light intensity from an intermediate level (440 μmol m−2 s−1) of white light to a high light treatment (1,000 μmol m–2 s–1) increased expression of several genes involved in dark CO2 fixation and malate transport at dawn, along with an increase in organic acid accumulation. Conclusions This study provides a useful genomics resource for investigating the molecular mechanism underlying the light regulation of physiology and metabolism in CAM plants. Our results support the hypothesis that both light intensity and light quality can modulate the CAM pathway through regulation of CAM-related genes in K. fedtschenkoi.

scholarly journals The Influence of Light Quality, Circadian Rhythm, and Photoperiod on the CBF-Mediated Freezing Tolerance

2013 ◽  
Vol 14 (6) ◽  
pp. 11527-11543 ◽  
Author(s):  
Punyakishore Maibam ◽  
Ganesh Nawkar ◽  
Joung Park ◽  
Vaidurya Sahi ◽  
Sang Lee ◽  
...  
Keyword(s):  
Circadian Rhythm ◽  
Freezing Tolerance ◽  
Light Quality
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