Biotechnology.

Biotechnology is the fusion of biology and technology. It changes and improves the characteristics of an organism at a cellular and molecular level for the benefit of mankind. Unlike conventional plant breeding methods, biotechnological techniques operate at tissue, cell, protoplast and molecular level for the genetic modification and subsequent screening for superior genotypes (Gosal et al., 2010). Biotechnology in a broad sense has been practiced for centuries for curd making, food preservation, pickle making and fermentation. However, biotechnology got a boost during the 1970s with the discovery of restriction enzymes, which led to the development of a variety of gene technologies; it is thus considered to be the greatest scientific revolution of the 20th century.

CALLUS INDUCTION AND DIFFERENTIATION (Review Article)

The science of plant tissue culture is the science of developing plant cells, tissues, or organs isolated from the mother plant or cell protoplast on culture media (George et al., 2008). The technology of plant tissue is one of the biotechnologies that led and still plays an important role in the service of man, especially in the field of propagation of many types of plants because of the advantages of this method, perhaps the most important of which is obtaining huge numbers of plants without pathogens and similar to the mother plant at a time relatively short and at any time of the year, in addition to using this technology in research and application fields, including breeding Plant improvement, production of medicinal drugs, drugs, and rapid breeding multiplication are among the applications of great importance that are followed by different methods of differentiation and formal formation such as the formation of transverse buds, stimulation of the growth of axillary buds and the development of asexual embryos (somatic embryos) as well as a study of the basic aspects of plant growth and development and secondary metabolism (Al-Kinani, 2002; Ford, 2000; Kasumi et al., 2004 and Gupta et al., 2006).

Changes in the structure and function of plant cell protoplast due to energy deficit

The influence of glycolysis inhibitors and of the respiratory chain inhibitors on the structure and function of protoplast were investigated in <i>Allium cepa</i> and <i>Tradescantia bracteata</i> meristematic cells. Hypertrophy of rough ER and modification of active transport were found, which was expressed by changes in the permeability of the plasmalemma and tonoplast and by depressed level of active ATP-ase. It is supposed that the formation of the characteristic rough endoplasmic reticulum (ER) configurations plays a significant role in bioenergetic processes by increasing the surface area active in glycolysis and in the respiratory chain connected with ER membranes.

In vitro fertilisation of maize by single egg and sperm cell protoplast fusion mediated by high calcium and high pH

SummaryWe present evidence for the fusion of isolated single maize egg and sperm cell protoplasts in a mannitol solution (400–430 mosmol/kg H2O) containing 0.05 M CaCl2 at pH 11.0, followed by cell division of the fusion products. These findings allow the performance of in vitro fertilisation of higher plants by combining single gametes as in lower plant and animal systems. Further, our findings open new avenues for investigating the basic mechanisms of adhesion and fusion of higher plant gametes and eventually for examining processes that inhibit polyspermy in higher plants.

THE CAUSE AND CURE OF LEAF CRISPING IN CUT ROSE STEMS

Roses are grown in Minnesota in the winter in closed greenhouses with the aid of HID lamps, and carbon dioxide enrichment. Although productivity is good, consumers often complain of a rapid dehydration or crisping of the leaves. Through a series of experiments using controlled environment chambers and known vase solutions we have determined that the crisping is due to the deposition of high levels of sucrose in the leaf cell walls due to transpiration from the leaves. The sucrose dehydrates the cell protoplast causing cell collapse and tissue death. Crisping is reduced by lowering the sucrose in the vase solution or reducing transpiration from the leaves. Abscisic acid added to the vase solution effectively reduced transpiration and crisping.