Blue Light Upregulates Auxin Signaling and Stimulates Root Formation in Irregular Rooting of Rosemary Cuttings

Irregular rooting of rosemary stem cuttings, causing differences in either stem maturation or responses to growth conditions, restricts uniform production. Here, rooting efficiency of apical, middle, and basal cuttings from rosemary stems was evaluated by controlling light conditions to prevent irregular rooting. The types of light applied to the cuttings were natural sunlight (NSL), fluorescent, red, and blue (BL) light. Among these light sources, BL significantly induced root growth of not only basal cuttings, but also apical and middle cuttings, whereas NSL induced poor root formation in apical and middle cuttings. In particular, the roots of apical cuttings exposed to BL grew twice as fast as those exposed to other types of light. The overexpression of BL-induced IAA synthetic genes confirmed the rooting patterns. IAA synthetic genes were significantly upregulated by BL in the apical and middle cuttings. Irradiating with 50 μmol photons m−2 s−1 BL resulted in similar root production levels among the cutting positions with high biomass, guaranteeing the successful production of uniform cuttings. Thus, the application of proper high-intensity BL promoted healthy, similar-quality rosemary cuttings among stem cutting positions.

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Phytochrome interacting factors 4 and 5 control seedling growth in changing light conditions by directly controlling auxin signaling

The Plant Journal ◽

10.1111/j.1365-313x.2012.05033.x ◽

2012 ◽

Vol 71 (5) ◽

pp. 699-711 ◽

Cited By ~ 281

Author(s):

Patricia Hornitschek ◽

Markus V. Kohnen ◽

Séverine Lorrain ◽

Jacques Rougemont ◽

Karin Ljung ◽

...

Keyword(s):

Seedling Growth ◽

Auxin Signaling ◽

Light Conditions ◽

Changing Light

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Automated Microscopy: Macro Language Controlling a Confocal Microscope and its External Illumination: Adaptation for Photosynthetic Organisms

Microscopy and Microanalysis ◽

10.1017/s1431927616000556 ◽

2016 ◽

Vol 22 (2) ◽

pp. 258-263 ◽

Cited By ~ 4

Author(s):

Gábor Steinbach ◽

Radek Kaňa

Keyword(s):

Light Sources ◽

Light Conditions ◽

Photosynthetic Organisms ◽

Automated Microscopy ◽

Photosynthetic Microorganisms ◽

Arduino Microcontroller ◽

Microscopy Data ◽

Kinetics Of ◽

Photosynthetic Cells

AbstractPhotosynthesis research employs several biophysical methods, including the detection of fluorescence. Even though fluorescence is a key method to detect photosynthetic efficiency, it has not been applied/adapted to single-cell confocal microscopy measurements to examine photosynthetic microorganisms. Experiments with photosynthetic cells may require automation to perform a large number of measurements with different parameters, especially concerning light conditions. However, commercial microscopes support custom protocols (throughTime Controlleroffered by Olympus orExperiment Designeroffered by Zeiss) that are often unable to provide special set-ups and connection to external devices (e.g., for irradiation). Our new system combining an Arduino microcontroller with theCell⊕Findersoftware was developed for controlling Olympus FV1000 and FV1200 confocal microscopes and the attached hardware modules. Our software/hardware solution offers (1) a text file-based macro language to control the imaging functions of the microscope; (2) programmable control of several external hardware devices (light sources, thermal controllers, actuators) during imaging via the Arduino microcontroller; (3) theCell⊕Findersoftware with ergonomic user environment, a fast selection method for the biologically important cells and precise positioning feature that reduces unwanted bleaching of the cells by the scanning laser.Cell⊕Findercan be downloaded fromhttp://www.alga.cz/cellfinder. The system was applied to study changes in fluorescence intensity inSynechocystissp. PCC6803 cells under long-term illumination. Thus, we were able to describe the kinetics of phycobilisome decoupling. Microscopy data showed that phycobilisome decoupling appears slowly after long-term (>1 h) exposure to high light.

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Generalized receptor law governs phototaxis in the phytoplanktonEuglena gracilis

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1422922112 ◽

2015 ◽

Vol 112 (22) ◽

pp. 7045-7050 ◽

Cited By ~ 29

Author(s):

Andrea Giometto ◽

Florian Altermatt ◽

Amos Maritan ◽

Roman Stocker ◽

Andrea Rinaldo

Keyword(s):

Algal Blooms ◽

Nonlinear Response ◽

Temporal Dynamics ◽

Freshwater Ecosystems ◽

Trophic Levels ◽

Light Fields ◽

Light Sources ◽

Mathematical Framework ◽

Heterogeneous Environments ◽

Light Conditions

Phototaxis, the process through which motile organisms direct their swimming toward or away from light, is implicated in key ecological phenomena (including algal blooms and diel vertical migration) that shape the distribution, diversity, and productivity of phytoplankton and thus energy transfer to higher trophic levels in aquatic ecosystems. Phototaxis also finds important applications in biofuel reactors and microbiopropellers and is argued to serve as a benchmark for the study of biological invasions in heterogeneous environments owing to the ease of generating stochastic light fields. Despite its ecological and technological relevance, an experimentally tested, general theoretical model of phototaxis seems unavailable to date. Here, we present accurate measurements of the behavior of the algaEuglena graciliswhen exposed to controlled light fields. Analysis ofE. gracilis’ phototactic accumulation dynamics over a broad range of light intensities proves that the classic Keller–Segel mathematical framework for taxis provides an accurate description of both positive and negative phototaxis only when phototactic sensitivity is modeled by a generalized “receptor law,” a specific nonlinear response function to light intensity that drives algae toward beneficial light conditions and away from harmful ones. The proposed phototactic model captures the temporal dynamics of both cells’ accumulation toward light sources and their dispersion upon light cessation. The model could thus be of use in integrating models of vertical phytoplankton migrations in marine and freshwater ecosystems, and in the design of bioreactors.

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Molecular identification of proline-rich protein genes induced during root formation in grape (Vitis vinifera L.) stem cuttings

Plant Cell & Environment ◽

10.1046/j.1365-3040.2003.01071.x ◽

2003 ◽

Vol 26 (9) ◽

pp. 1497-1504 ◽

Cited By ~ 15

Author(s):

P. THOMAS ◽

M. M. LEE ◽

J. SCHIEFELBEIN

Keyword(s):

Vitis Vinifera ◽

Molecular Identification ◽

Root Formation ◽

Vitis Vinifera L ◽

Stem Cuttings ◽

Proline Rich Protein

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Auto White Balance Algorithm in Digital Camera

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.182-183.2080 ◽

2012 ◽

Vol 182-183 ◽

pp. 2080-2084

Author(s):

Jie Li ◽

Xue Xiang Wang ◽

Hao Liu

Keyword(s):

Hardware Implementation ◽

Digital Camera ◽

Low Complexity ◽

Light Sources ◽

Light Conditions ◽

Threshold Method ◽

White Balance ◽

White Point ◽

A New Technique ◽

Better Than

Auto white balance (AWB) is an important function of digital camera. The purpose of white balance is to adjust the image to make it look like taken under standard light conditions. We present a new technique to detect the reference white point of image in this paper. This technique detects the white point of image by using dynamic threshold method, thus making it more flexible and more applicable compared to other algorithms. We test 50 images which were taken under different light sources, and find that this algorithm is better than or comparable to other algorithms both in subjective and objective aspects. At the same time, this algorithm has low complexity, and it can be easily applied to hardware implementation.

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Mechanisms Underlying the Regulation of Root Formation in Malus hupehensis Stem Cuttings by Using Exogenous Hormones

Journal of Plant Growth Regulation ◽

10.1007/s00344-016-9628-8 ◽

2016 ◽

Vol 36 (1) ◽

pp. 174-185 ◽

Cited By ~ 3

Author(s):

Wangxiang Zhang ◽

Junjun Fan ◽

Qianqian Tan ◽

Mingming Zhao ◽

Fuliang Cao

Keyword(s):

Root Formation ◽

Stem Cuttings ◽

Exogenous Hormones ◽

Malus Hupehensis

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The microRNA476a/RFL module regulates adventitious root formation through a mitochondria-dependent pathway in Populus

10.1101/852178 ◽

2019 ◽

Author(s):

Changzheng Xu ◽

Yuanxun Tao ◽

Xiaokang Fu ◽

Li Guo ◽

Haitao Xing ◽

...

Keyword(s):

Adventitious Root ◽

Developmental Plasticity ◽

Adventitious Rooting ◽

Adventitious Root Formation ◽

Auxin Signaling ◽

Stem Cuttings ◽

Pentatricopeptide Repeat ◽

Dynamic Regulation ◽

Mitochondrial Regulation ◽

Mitochondrial Homeostasis

AbstractAdventitious root (AR) formation at the base of stem cuttings determines the efficiency of clonal propagation for woody plants. Many endogenous and environmental factors influence AR formation. However, our knowledge about the regulation of AR development by mitochondrial metabolism in plants is very limited. Here we identified Populus-specific miR476a as a novel regulator of wound-induced adventitious rooting via orchestrating mitochondrial homeostasis in poplar. MiR476a exhibited inducible expression during AR formation and directly targets several Restorer of Fertility like (RFL) genes encoding mitochondrion-localized pentatricopeptide repeat proteins. Genetic modification of miR476-RFL expression revealed the miR476/RFL-mediated dynamic regulation of mitochondrial homeostasis on AR formation in transgenic poplar. Furthermore, mitochondrial perturbation via exogenous chemical inhibitor validated that the miR476a/RFL-directed AR formation depended on mitochondrial regulation though modulating the auxin pathway. Our results established a miRNA-directed mitochondrion-auxin signaling cascade required for AR development, providing novel insights into the understanding of mitochondrial regulation on plant developmental plasticity.

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