ABSTRACT
Antisense RNA is a means of down-regulating gene expression. In eukaryotes, it is currently the only effective means of inhibiting the expression of genes that are members of multigene families or present in multiple copies per cell, i.e., many nuclear genes and all organelle genes. In the most extensive study of the sort in plants, Cornelissen found evidence for antisense mRNA inhibition at both the levels of target:antisense duplex RNA degradation in the nucleus and translation in the cytoplasm. While much attention has been focused on the molecular biology and biochemistry of activase since its discovery in the mid-1980s, less attention has been paid to understanding the control that activase exerts on the photosynthetic process. To determine the impact of reductions in activase protein on photosynthetic rates, we determined CO2 -exchange rates on the first fully expanded leaves of the T1 progeny and control plants growing in the greenhouse.
