Secondary growth

V. GROWTH, SECONDARY NUCLEATION, AND LAURITZEN-HOFFMAN THEORY... 

Ruhmann S, Leser C, Bannert M, Treutter D. 2002. Relationship between growth, secondary metabolism, and resistance of apple. Plant Biol 4 137-193. 

Cronin, G. and Hay, M. E., Effects of light and nutrient availability on the growth, secondary chemistry, and resistance to herbivory of two brown seaweeds, Oikos, 77, 93, 1996. 

Relatively stable Relatively stable Secondary growth Secondary growth Equilibrium Unstable... 

In instances of unbalanced growth, secondary metabolites have been envisioned by some as shunt metabolites produced in order to reduce abnormal concentrations of normal cellular constituents. The synthesis of enzymes designed to carry out secondary metabolism permits primary metabolic enzymes to continue to function until such time as circumstances are propitious for renewed metabolic activity and growth. For example, this could be linked to the depletion of nutrients such as phosphorus or nitrogen (Bu Lock, 1980 Haslam, 1986). 

To introduce additional functionality and to allow for a wider variety of structural features, branching of the primary CNF/CNT with secondary, usually thirmer ones, has been performed [113,114]. Primary as well as secondary carbon nanostructures were grown in CVD processes. After electrodepositing iron as growth catalyst and subsequent CNT growth, secondary CNTs were grown in a similar fashion to yield hierarchically structured layers. The principles of such an approach are visualized in Figure 10.22. It was shown with impedance spectroscopy and other techniques, that the electrochemical properties of such composites are superior to those of unbranched CNF. 

This reaction takes place at 60°C in a benzene solution, but not all the radicals produced may go on to initiate chain growth. Secondary reactions can occur between the radicals produced because of the confining effect of solvent molecules (the cage effect). Primary recombination can occur when the two benzoyloxy radicals produced are unable to diffuse away from each other fast enough... 

Plant cell walls are of two general types primary cell walls and secondary cell walls. Primary cell walls are laid down by undifferentiated cells that are still growing and it is these primary walls that control cell growth. Secondary walls are derived from primary cell walls by cells which have stopped growing and are differentiating. This review is concerned with the structure of primary cell walls and will be limited to a consideration of the primary cell walls of dicotyledonous plants. The primary cell walls of dicots differ, at least to some degree, from the primary cell walls of monocots and from the cell walls of lower plants (3, 107). 

Bacteria produce a wide variety of antagonistic factors that include primary and secondary metabolites (Piard and Desmazeaud, 1992). Primary metabolites are produced during the growth phase of an organism and play a vital role in active growth. Secondary metabolites can be described as compounds that are produced after active growth has taken place and which... 

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