Inducible genes

Rao JR, JE Cooper (1994) Rhizobia catabolize nod gene-inducing flavonoids via C-ring fission mechanisms. J Bacterial 176 5409-5413. 

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). 

A. J. Dharmatilake and W. D. Baker, Cheinotaxis of Rhizohium meliloti towards nodulation gene inducing compounds from alfalfa roots. Applied and Environmental Microbiology 5S 1153 (1992). 

The basic structures of flavanones, flavones, and isoflavones together with coumestrol, an intermediate in the phenylpropane metabolism, are given in Fig. 2. The 3,5,7,3 -tetrahydroxy-4 -methoxyflavanone is a nod gene inducer in Rhizo-bium leguminosarum bv. viciae the 3, 4, 5,7-tetrahydroxyflavone, in Rhizobium ineliloti and 4,7-dihydroxyisoflavone, in Bradyrhizobium japonicum. Coumestrol, an intermediate in phenylpropane metabolism, is only a weak inducer (7). 

U. A. Hartwig and D. A. Phillips, Relea.se and modification of nrW-gene-inducing flavonoids from alfalfa seeds. Plant Physiol. 95 804 (1991). 

M. C. Bolanos-Vasquez and D. Werner, Effects of Rhizohium tropici, R. etii, and R. leguminosarum bv. phaseoU on nod gene-inducing flavonoids in root exudates of Phaseohis vulgaris. Molec. Plant Microbe Interact. 10 229 (1997). 

U. A. Hartwig, C. A. Maxwell, C. M. Joseph, and D. A. Phillips, Interactions among flavonoid nod genes inducers released from alfalfa seeds and roots. Plant Phy.siol 97 1138 (1989). 

Mintz, B., and Russell, E. S. (1957). Gene-induced embryological modifications of primordial germ cells in the mouse. J. Exp. Zool. 134 207-230. 

For example, a single hormone-activated gene induces the formation of many mRNA molecules and each mRNA molecule may be used to synthesize many enzyme molecules. Furthermore, the effects of hormones using this mechanism are prolonged. As long as the newly synthesized enzyme is active, the effect of the initiating hormone persists. 

Figure 1. The frequencies of amber mutations in the lacl gene induced by BPDE. Solid bars, individual sites at which we detected mutations open bars, sites at which we did not detect mutations asterisks (in a), sites at which the target codon contains 5-methylcytosine.

Table 2. Number of genes induced (P) or suppressed (A) in Arabidopsis thaliana plants exposed to 240 pM of Ph 2 ions for 14 days.

Ghose K, Dey S, Barton H, Loake GJ, Basu D (2008) Differential profiling of selected defence-related genes induced on challenge wiihAlternaria brassicicola in resistant white mustard and their comparative expression pattern in susceptible India mustard. Mol Plant Pathol 9 763-775... 

Diaz-Meco MT, Municio MM, Frutos S, Sanchez P, Lozano J, Sanz L, Moscat J (1996) The product of par 4, a gene induced during apoptosis, interacts selectively with the atypical isoforms of protein kinase C. Cell 86 777-786 Dietel M, Arps H, Lage H, Niendorf A (1990) Membrane vesicle formation due to acquired mitoxanthrone resistance in human gastric carcinoma cell line EPG85-257. Cancer Res 50 6100-6106... 

Moore RY, Speh JC, Card JP 1995 The retinohypothalamic tract originates from a distinct subset of retinal ganglion cells. J Comp Neurol 352 351—366 Morris ME, Viswanathan N, Kuhlman S, Davis PC, Weitz CJ 1998 A screen for genes induced in the suprachiasmatic nucleus by light. Science 279 1544—1547 Mrosovsky N 1999 Masking history, definitions, and measurement. Chronobiol Int 16 415-429... 

Some nod Gene Inducers Released by Different Legumes... 

Hungria, M., Joseph, C.M., and Phillips, D.A., Rhizobium nod gene inducers exuded naturally from roots of common bean Phaseolus vulgaris L.), Plant Physiol, 97, 759, 1991. 

Leon-Barrios, M. et al.. Isolation of Rhizobium meliloti nod gene inducers from alfalfa rhizosphere soil, Appl Environ. Microbiol, 59, 636, 1993. 

Bolanos-Vasquez, M.C. and Werner, D., Effects of Rhizobium tropici, R. etli, and R. legumino-sarum bv. phaseoli on nod gene-inducing flavonoids in root exudates of Phaseolus vulgaris. Mol Plant-Microbe Interact., 10, 339, 1997. 

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