Molecular signaling

Depending on the matrix and the post-ionization technique, SN" spectra can be dominated by atomic or molecular signals. In particular, compounds with high mass... 

Bergstralh DT, Ting JP (2006) Microtubule stabilizing agents their molecular signaling consequences and the potential for enhancement by drug combination. Cancer Treat Rev 32 166-179... 

Plant survival and crop productivity are strictly dependent on the capability of plants to adapt to different environments. This adaptation is the result of the interaction among roots and biotic and abiotic components of soil. Processes at the basis of the root-soil interaction concern a very limited area surrounding the root tissue. In this particular environment, exchanges of energy, nutrients, and molecular signals take place, rendering the chemistry, biochemistry, and biology of this environment different from the bulk soil. 

Chapters 7 and 9 discuss specific exchange of molecular signals (the so-called molecular cross talk ) between beneficial microorganisms, such as rhizo-bia and mycorrhizas, and their host plants. Molecular cross talk seems to be a prerequisite mechanism for most of the plant infection by soil microorganisms (14). Only for a few microbial infections, however, the sequence and type of molecular signals involved have been characterized. Thus, there is the need for further studies to elucidate the unknown molecular cross talk between the most common rhizobacteria and fungi and the plant roots it is also needed to better understand how molecular cross talk responds to the changing environmental conditions. The potential applications of these studies are important because the... 

ROOT-MICROBES AND MICROBES-MICROBES MOLECULAR SIGNALS... 

According to Hungria and Stacey (31) more than 4000 flavonoids have been identified within the plant kingdom and some of them have been recognized as nod gene-inducers (Table 1). In addition, root flavonoids have been suggested as molecular signals for the initiation and development of mycorrhizal infection (Chaps. 7 and 9). 

Any bacterial species living in a mixed microbial population, such as that of the rhizosphere, may encounter not only the molecular signal produced by a cell of the. same species but also molecular signals produced by cells of different species. The situation is made more complex by the presence of plant molecular signals, and by the fact that the same AHL molecule can be used to regulate the... 

In conclusion, the behavior of the molecular signals can be markedly different in soil with respect to that observed in microcosm experiments involving only the ho.st plant and the infecting microorganism or a mixed microbial population, both without soil particles. Studies are needed to compare the diffusion of molecular signals in the presence of clay and/or humic barriers. 

M. Hungria, and G. Stacey, Molecular signals exchanged between plants and rhizo-bia basic aspects and potential application in agriculture. Soil Biol. Biochem. 29 819 (1997). 

The production and release of organic molecules by the root systems of plants have been extensively studied under a wide range of soil conditions (nutrient and water availability, pre.sence of pollutants, etc.,. see Chaps. 2 and 3). Furthermore it has been clearly demonstrated that soil microorganisms are able to produce molecules that can affect the physiology and architecture of roots (3) evidence has been also provided that molecular signals between plants and microorganisms are exchanged (see Chap. 7). 

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