Thansgenic peanut plants obtained by particle bombardment via somatic embryogenesis regeneration system

After pre-culture and treatment of osmosis, cotyledons of immature peanut (Arachis hypogaea L.) zygotic embryos were transformed via particle bombardment with a plasmid containing a chimeric hph gene conferring resistance to hygromycin and a chimeric intron-gus gene. Selection for hygromycin resistant calluses and somatic embryos was initiated at 10th d post-bombardment on medium containing 10-25 mg/L hygromycin. Under continuous selection, hygromycin resistant plantlets were regenerated from somatic embryos and were recovered from nearly 1.6% of the bombarded cotyledons. The presence and integration of foreign DNA in regenerated hygromycin resistant plants was confirmed by PCR (polymerase chain reaction) for the intron-gus gene and by Southern hybridization of the hph gene. GUS enzyme activity was detected in leaflets from transgenic plants but not from control, non-transformed plants. The production of transgenic plants are mainly based on a newly improved somatic embryogenesis regeneration system developed by us.

Evaluation of the potential exposure of butterflies to genetically modified maize pollen in protected areas in Italy

Environmental impacts of genetically modified crops are mandatorily assessed during their premarket phase. One of the areas of concern is the possible impact on nontar- get organisms. Crops expressing Cry toxins might affect Lepidoptera larvae living outside cultivated fields, through pollen deposition on wild plants, which constitute their food source. While pollen toxicity varies among different events, possible exposure ofnontarget species depends on the agro-environmental conditions. This study was conducted in two protected areas in Italy, characterized by different climatic conditions, where many Lepi- doptera species thrive in proximity to maize cultivations. To estimate the possible exposure in absence of the actual stressor （e.g., Cryl-expressing maize plants）, we conducted a two-year field survey of butterflies and weeds. Indicator species were selected--Aglais （Inachis） io in the Northern site and Vanessa cardui in the Southern site--and their phe- nology was investigated. Pollen dispersal from maize fields was measured by collection in Petri dishes. Duration and frequency of exposure was defined by the overlap between pollen emission and presence of larvae on host plants. Different risk scenarios are expected in the two regions： highest exposure is foreseen forA. io in the Northern site, while minimal exposure is estimated for V. cardui in the Southern site. In the latter case, locally grown maize cultivars flower in mid-summer in coincidence with an aestivation period for several butterfly species due to hot and dry conditions. Moreover, host plants of V. cardui are at the end of their life cycle thus limiting food availability.

HAL1 mediate salt adaptation in Arabidopsis thaliana

The yeast HAL1 gene was introduced into Arabidopsis thaliana by Agrobacterium tumefaciens-mediated transformation with vacuum infiltration under the control of CaMV 35S promoter. Thirty-three individual kanamycin resistant plants were obtained from 75,000 seeds. Southern blotting analysis indicated that HAL1 gene had been integrated into all of the transgenic plants’ genomes. The copy number of HAL1 gene in transgenic plants was mostly 1 to 3 by Southern analysis. Phenotypes of transgenic plants have no differences with wild type plants. several samples of transformants were self-pollinated, and progenies from transformed and non-transformed plants (controls) were evaluated for salt tolerance and gene expression. Measurement of concentrations of intracellular K+ and Na+ showed that transgenic lines were able to retain less Na+ than that of the control under salt stress. Results from different tests indicated the expression of HAL1 gene promotes a higher level of salt tolerance in vivo in the transgenic Arabidopsis plants.

Diversity of Microbial Community in a Paddy Soil with cry1Ac/cpti Transgenic Rice

Two types of crylAc/cpti transgenic rice （GM1 and GM2） and their parental non-crylAc/cpti rice （CK1 and CK2） were planted in the field at Wufeng, Fhjian Province, China for four years to investigate the influence of genetically modified rice on diversity of bacterial and fungal community in the paddy soil. The community composition and abundance of bacteria or fungi in the paddy soil were assessed at different growth stages of rice by denaturing gradient gel electrophoresis and real-time polymerase chain reaction based on 16S rRNA gene or SSU rRNA gene in the 4th year after the experimental establishment. The composition of bacterial or fungal community changed during rice growth, while no significant differences were observed between the fields cultivated with GM1 and CK1, or between the fields cultivated with GM2 and CK2 in either bacterial or fungal community composition. The copy numbers of bacterial 16S rRNA gene in the soils with CK1, CK2, GM1 and GM2 ranged from 5.64 x 10i1 to 6.89 x 10li copies g-1 dry soil at rice growth stages, and those of fungal SSU rRNA gene from 5.24 x 10s to 8.68 x l0s copies g-1 dry soil. There were no marked differences in the copies of bacterial 16S rRNA gene or fungal SSU rRNA gene between CK1 and GM1 or between CK2 and GM2 at any growth stage of rice. Planting crylAc/cpti transgenic rice had no significant effect on composition and abundance of bacterial and fungal community in paddy soil during the rice growing season at least in the short term.