TRANSGENIC MALE-STERILE PLANT INDUCED BY AN UNEDITED ATP9 GENE IS RESTORED TO FERTILITY BY INHIBITING ITS EXPRESSION WITH ANTISENSE RNA

We have previously shown that the expression of an unedited atp9 chime ric gene correlated with male-sterile phenotype in transgenic tobacco plant. To study the relationship between the expression of chimeric ge ne and the male-sterile trait, hemizygous and homozygous transgenic to bacco lines expressing the antisense atp9 RNA were constructed. The an tisense producing plants were crossed with a homozygous male-sterile l ine, and the F1 progeny was analyzed. The offspring from crosses betwe en homozygous lines produced only male-fertile plants, suggesting that the expression antisense atp9 RNA abolishes the effect of the unedite d chimeric gene. In fact, the plants restored to male fertility showed a dramatic reduction of the unedited atp9 transcript levels, resultin g in normal flower development and seed production. These results supp ort our previous observation that the expression of unedited atp9 gene can induce male sterility.