Acceleration of plant growth by D.C. electric field

Author(s):  
T. Okumura ◽  
Y. Muramoto ◽  
N. Shimizu
Keyword(s):  
2020 ◽  
Vol 11 (1) ◽  
pp. 63-69
Author(s):  
WAI KEONG LOKE ◽  
Halimi Mohd Saud

Electrotransformation was successfully transferred a 21.6 kb cosmid vector pLAFR1 into the selected Plant Growth-Promoting Rhizobacteria (PGPR) and Chromobacterium violaceum with maximum efficiency about 107 transformants/µg at electric field strength of 10kV/cm for shorter pulse length range between 4.1 to 4.4 milliseconds and about 108 transformants/µg at electric field strength of 5kV/cm for a longer pulse length range between 8.5 to 8.7 milliseconds. Longer incubation period will increase the transformation efficiency but continuing increasing the period after 20 hours will decrease the transformation efficiency.  


Nature Food ◽  
2022 ◽  
Author(s):  
Xunjia Li ◽  
Jianjun Luo ◽  
Kai Han ◽  
Xue Shi ◽  
Zewei Ren ◽  
...  

Author(s):  
G. F. Rempfer

In photoelectron microscopy (PEM), also called photoemission electron microscopy (PEEM), the image is formed by electrons which have been liberated from the specimen by ultraviolet light. The electrons are accelerated by an electric field before being imaged by an electron lens system. The specimen is supported on a planar electrode (or the electrode itself may be the specimen), and the accelerating field is applied between the specimen, which serves as the cathode, and an anode. The accelerating field is essentially uniform except for microfields near the surface of the specimen and a diverging field near the anode aperture. The uniform field forms a virtual image of the specimen (virtual specimen) at unit lateral magnification, approximately twice as far from the anode as is the specimen. The diverging field at the anode aperture in turn forms a virtual image of the virtual specimen at magnification 2/3, at a distance from the anode of 4/3 the specimen distance. This demagnified virtual image is the object for the objective stage of the lens system.


Author(s):  
Patrick P. Camus

The theory of field ion emission is the study of electron tunneling probability enhanced by the application of a high electric field. At subnanometer distances and kilovolt potentials, the probability of tunneling of electrons increases markedly. Field ionization of gas atoms produce atomic resolution images of the surface of the specimen, while field evaporation of surface atoms sections the specimen. Details of emission theory may be found in monographs.Field ionization (FI) is the phenomena whereby an electric field assists in the ionization of gas atoms via tunneling. The tunneling probability is a maximum at a critical distance above the surface,xc, Fig. 1. Energy is required to ionize the gas atom at xc, I, but at a value reduced by the appliedelectric field, xcFe, while energy is recovered by placing the electron in the specimen, φ. The highest ionization probability occurs for those regions on the specimen that have the highest local electric field. Those atoms which protrude from the average surfacehave the smallest radius of curvature, the highest field and therefore produce the highest ionizationprobability and brightest spots on the imaging screen, Fig. 2. This technique is called field ion microscopy (FIM).


2015 ◽  
Vol 58 ◽  
pp. 61-70 ◽  
Author(s):  
Paul B. Larsen

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.


1993 ◽  
Vol 89 (1) ◽  
pp. 33-39 ◽  
Author(s):  
Jeff S. Kuehny ◽  
Mary C. Halbrooks

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