A genetic complementation system was developed
in which tobacco etch virus (TEV) polymerase (NIb)-
expressing transgenic plants or protoplasts were inoculated
with NIb-defective TEV mutants. A β-glucuronidase (GUS)
reporter gene integrated into the genomes of parental and four
mutant viruses was used to assay RNA amplification. Two
mutants (termed VNN...
Satellite measurements allow global assessments of phytoplankton concentrations and, from observed temporal changes in biomass, direct access to net biomass accumulation rates (r). For the subarctic Atlantic basin, analysis of annual cycles in r reveals that initiation of the annual blooming phase does not occur in spring after stratification surpasses...