Growth and Development in Range Grasses. V. Photoperiodic Responses of Clonal Divisions of Three Latitudinal Strains of Side-Oats Grama

1945 ◽  
Vol 106 (4) ◽  
pp. 382-401 ◽  
Author(s):  
Charles E. Olmsted
Keyword(s):  
Growth And Development ◽  
Photoperiodic Responses ◽  
Range Grasses

scholarly journals Phytochromes measure photoperiod in Brachypodium

2019 ◽  
Author(s):  
Mingjun Gao ◽  
Feng Geng ◽  
Cornelia Klose ◽  
Anne-Marie Staudt ◽  
He Huang ◽  
...  
Keyword(s):  
Circadian Clock ◽  
Conceptual Framework ◽  
Growth And Development ◽  
Clock Genes ◽  
Brachypodium Distachyon ◽  
Adaptive Trait ◽  
Long Day ◽  
Northern Latitudes ◽  
Photoperiodic Responses ◽  
Clock Protein

SummaryDaylength is a key seasonal cue for animals and plants. In cereals, photoperiodic responses are a major adaptive trait, and alleles of clock genes such as PHOTOPERIOD DEPENDENT1 (PPD1) and EARLY FLOWERING3 (ELF3) have been selected for in breeding barley and wheat for more northern latitudes (Faure et al., 2012; Turner, Beales, Faure, Dunford, & Laurie, 2005). How monocot plants sense photoperiod and integrate this information into growth and development is not well understood. We show that in Brachypodium distachyon, phytochrome C (phyC) acts as a molecular timer, directly communicating information to the circadian clock protein ELF3. In this way, ELF3 levels integrate night length information. ELF3 is a central regulator of photoperiodism in Brachypodium, and elf3 mutants display a constitutive long day transcriptome. Conversely, conditions that result in higher levels of ELF3 suppress long day responses. We are able to show that these effects are direct, as ELF3 and phyC occur in a common complex, and they associate with the promoters of a number of conserved regulators of photoperiodism, including PPD1. Consistent with observations in barley, we are able to show that PPD1 overexpression accelerates flowering in SD and is necessary for rapid flowering in response to LD. These findings provide a conceptual framework for understanding observations in the photoperiodic responses of key crops, including wheat, barley and rice.

An ultrastructural study of vegetative incompatibility in plants

1978 ◽  
Vol 36 (2) ◽  
pp. 436-437
Author(s):  
Randy Moore
Keyword(s):  
Ultrastructural Study ◽  
Cell Walls ◽  
Growth And Development ◽  
Solanum Pennellii ◽  
Initial Product ◽  
Basic Aspect ◽  
Tissue Interactions ◽  
Graft Interface ◽  
Antigen Antibody ◽  
Standard Fixation

Cell and tissue interactions are a basic aspect of eukaryotic growth and development. While cell-to-cell interactions involving recognition and incompatibility have been studied extensively in animals, there is no known antigen-antibody reaction in plants and the recognition mechanisms operating in plant grafts have been virtually neglected.An ultrastructural study of the Sedum telephoides/Solanum pennellii graft was undertaken to define possible mechanisms of plant graft incompatibility. Grafts were surgically dissected from greenhouse grown plants at various times over 1-4 weeks and prepared for EM employing variations in the standard fixation and embedding procedure. Stock and scion adhere within 6 days after grafting. Following progressive cell senescence in both Sedum and Solanum, the graft interface appears as a band of 8-11 crushed cells after 2 weeks (Fig. 1, I). Trapped between the buckled cell walls are densely staining cytoplasmic remnants and residual starch grains, an initial product of wound reactions in plants.

Identification of calcium oxalate crystals in dried or fixed tobacco leaf

1984 ◽  
Vol 42 ◽  
pp. 288-289
Author(s):  
Vicki L. Baliga ◽  
Mary Ellen Counts
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Calcium Oxalate ◽  
Growth And Development ◽  
Polarized Light ◽  
Calcium Oxalate Crystals ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Electron

Calcium is an important element in the growth and development of plants and one form of calcium is calcium oxalate. Calcium oxalate has been found in leaf seed, stem material plant tissue culture, fungi and lichen using one or more of the following methods—polarized light microscopy (PLM), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and x-ray diffraction.Two methods are presented here for qualitatively estimating calcium oxalate in dried or fixed tobacco (Nicotiana) leaf from different stalk positions using PLM. SEM, coupled with energy dispersive x-ray spectrometry (EDS), and powder x-ray diffraction were used to verify that the crystals observed in the dried leaf with PLM were calcium oxalate.

SEM study of the morphological effects of kinetin and zeatin on the growth and development of the apical meristem in wheat

1995 ◽  
Vol 53 ◽  
pp. 978-979
Author(s):  
G. M. Hutchins ◽  
J. S. Gardner
Keyword(s):  
Growth And Development ◽  
Furfuryl Alcohol ◽  
Apical Meristem ◽  
Plant Cells ◽  
Triticum Aestivum L ◽  
Morphological Development ◽  
Naturally Occurring ◽  
Chinese Spring Wheat ◽  
Sem Study ◽  
Moist Environment

Cytokinins are plant hormones that play a large and incompletely understood role in the life-cycle of plants. The goal of this study was to determine what roles cytokinins play in the morphological development of wheat. To achieve any real success in altering the development and growth of wheat, the cytokinins must be applied directly to the apical meristem, or spike of the plant. It is in this region that the plant cells are actively undergoing mitosis. Kinetin and Zeatin were the two cytokinins chosen for this experiment. Kinetin is an artificial hormone that was originally extracted from old or heated DNA. Kinetin is easily made from the reaction of adenine and furfuryl alcohol. Zeatin is a naturally occurring hormone found in corn, wheat, and many other plants.Chinese Spring Wheat (Triticum aestivum L.) was used for this experiment. Prior to planting, the seeds were germinated in a moist environment for 72 hours.

Mechanisms of ethylene biosynthesis and response in plants

2015 ◽  
Vol 58 ◽  
pp. 61-70 ◽  
Author(s):  
Paul B. Larsen
Keyword(s):  
Plant Growth ◽  
Growth And Development ◽  
Ethylene Biosynthesis ◽  
Unsaturated Hydrocarbon ◽  
Flower Senescence ◽  
Detailed Knowledge ◽  
Plant Growth And Development ◽  
Step Process ◽  
Ethylene Response ◽  
Ethylene Signalling

Ethylene is the simplest unsaturated hydrocarbon, yet it has profound effects on plant growth and development, including many agriculturally important phenomena. Analysis of the mechanisms underlying ethylene biosynthesis and signalling have resulted in the elucidation of multistep mechanisms which at first glance appear simple, but in fact represent several levels of control to tightly regulate the level of production and response. Ethylene biosynthesis represents a two-step process that is regulated at both the transcriptional and post-translational levels, thus enabling plants to control the amount of ethylene produced with regard to promotion of responses such as climacteric flower senescence and fruit ripening. Ethylene production subsequently results in activation of the ethylene response, as ethylene accumulation will trigger the ethylene signalling pathway to activate ethylene-dependent transcription for promotion of the response and for resetting the pathway. A more detailed knowledge of the mechanisms underlying biosynthesis and the ethylene response will ultimately enable new approaches to be developed for control of the initiation and progression of ethylene-dependent developmental processes, many of which are of horticultural significance.

The Fundamentals of the Clinical Fellowship Experience

2016 ◽  
Vol 1 (11) ◽  
pp. 81-85
Author(s):  
Melanie Hudson
Keyword(s):  
Growth And Development ◽  
Transition Period ◽  
Clinical Skills ◽  
Practical Experience ◽  
Professional Experience ◽  
New Graduate ◽  
Independent Practitioner

The Clinical Fellowship Experience is described by the American Speech-Hearing-Language Association (ASHA) as the transition period from constant supervision to independent practitioner. It is typically the first paid professional experience for the new graduate, and may be in a setting with which the new clinician has little or even no significant practical experience. The mentor of a clinical fellow (CF) plays an important role in supporting the growth and development of this new professional in areas that extend beyond application of clinical skills and knowledge. This article discusses how the mentor may provide this support within a framework that facilitates the path to clinical independence.

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