Transgenic tobacco plants low in phytochrome A content

Tobacco (Nicotiana tabacum) plants were transformed with a construct encodi ng phytochrome A (PHYA) antisense RNA. The construct inserted into the toba cco genome contained squash PHYA cDNA in an antisense orientation under the cauliflower mosaic virus 35S promoter providing for gene expression in hig her plant tissues. Using immunoblot analysis and Z3-B1 antibodies against P HYA, the authors demonstrated that the PHYA content of the transgenic plant s was lower than that of the wild-type plants. The studies of PHYA-dependen t inhibition of hypocotyl elongation by high-intensity far-red light showed a considerable decrease in light sensitivity of the transgenic hypocotyl c haracteristic for a phyA mutation.