Methyl jasmonate and miconazole differently affect arteminisin production and gene expression in Artemisia annua suspension cultures.

Artemisia annua L. is a herb traditionally used for treatment of fevers. The glandular trichomes of this plant accumulate, although at low levels, artemisinin, which is highly effective against malaria. Due to the great importance of this compound, many efforts have been made to improve knowledge on artemisinin production both in plants and in cell cultures. In this study, A. annua suspension cultures were established in order to investigate the effects of methyl jasmonate (MeJA) and miconazole on artemisinin biosynthesis. Twenty-two micro molar MeJA induced a three-fold increase of artemisinin production in around 30 min; while 200 µm miconazole induced a 2.5-fold increase of artemisinin production after 24 h, but had severe effects on cell viability. The influence of these treatments on expression of biosynthetic genes was also investigated. MeJA induced up-regulation of CYP71AV1, while miconazole induced up-regulation of CPR and DBR2.

Agrobacterium rhizogenes rol genes induce productivity-related phenotypical modifications in "creeping-rooted" alfalfa types.

Agrobacterium rhizogenes rol genes were transferred individually or in combination into the forage legume Medicago sativa L. (alfalfa). Kanamycin resistant, neomycin phosphotransferase II positive plants showed the presence of the rol inserts in their genome. Phenotypical evaluation of transgenic populations indicated significant morphological alterations of the root system, stem number per plant and plant structure. A possible utilization of these transgenics in breeding programs of the so-called "creeping-rooted" alfalfa strains is discussed.

Chlorsulfuron resistance in Daucus carota cell lines and plants:Involvement of gene amplification.

Daucus carota L. cell lines stably resistant to the herbicide chlorsulfuron (CS) have been isolated according to a stepwise selection. Studies carried out during different selection steps show that the specific activity of the target enzyme acetohydroxyacid synthase (AHAS) increases along with CS resistance. Southern hybridization analysis performed with aBrassica napus AHAS probe in a CS highly-resistant cell line reveals the presence of a greatly amplifiedEcoRI fragment of genomic DNA. This indicates that AHAS overproduction induced by stepwise selection is due to gene amplification. Regenerants from some resistant cell lines maintained the CS-resistant trait at the whole plant level.

Genetic transformation in the grain legume Cicer arietinum L. (chickpea).

In the grain legume Cicer arietinum L. (chickpea), the seed-derived embryo axes deprived of the apical meristem were able to regenerate adventitious shoots on Murashige and Skoog (1962) medium supplemented with kinetin. This protocol was suitable for Agrobacterium-mediated gene transfer by the co-cultivation technique. Chickpea transgenic plants showed neomycin phosphotransferase II and ß-glucuronidase activities and the presence in their genome of integrated bacterial DNA.

Chromosomal aberration analysis of workers in tannery industries.

A chromosomal aberration analysis was carried out on tannery workers and on matched controls. Workers were engaged in 2 different processing areas, the drum and the finishing workshop. A weak but significant increase in chromosomal aberration frequencies was shown in drum workers in comparison to controls, no difference was shown in finishers.

Induction of chromosomal aberrations and SCE by chloramphenicol.

The induction of chromosomal aberrations and sister-chromatid exchanges (SCE) was studied in human lymphocyte cultures treated with chloramphenicol (CAP), an antimicrobial agent acting by inhibiting protein synthesis. Moreover chromosomal aberrations and sister-chromatid exchanges were studied in bone marrow cells of treated mice and in Chinese hamster cell cultures (V79) respectively. While no aberrations were induced by short treatments in human lymphocytes exposed in G1 and G2 phases, high frequencies of aberrations, exclusively of the chromatid type, were induced when the drug was administered during a whole cell cycle. Aberrant metaphases were detected only at the end and a few hours after the end of treatment; at later times aberrant cells reached control values. Doses producing aberrations only slightly increased SCE both in human lymphocytes and in V79 cells. In mouse bone marrow cells CAP induced a high mitotic delay and few structural aberrations; intrachromosomal vacuoles were observed.

Chromosomal monitoring of chromium-exposed workers.

A cytogenetic analysis was carried out on peripheral blood lymphocytes of workers exposed to chromite in a ferrochromium plant, to evaluate the possible existence of genetic damage. A quantitatively limited increase in aberrant cell frequencies was detected in subjects working in the furnace sector. The data were analyzed by several statistical approaches.