摘要 |
<p>An inducible promoter is used to regulate expression of a gene which is known to be critical to male fertility. The selected gene's control sequences are modified so that it is normally "off" and as a result the plants are male sterile. When it is desired to reproduce the male sterile plants, male fertility is restored by treating the plants with a non-phytotoxic chemical which induces expression of the critical gene. A critical gene is one which affects flavonol production and in particular compounds of the formula: <IMAGE> wherein R1, R2, R3, R4, R5, R7, and R8, are hydrogen, hydroxyl or alkoxy having from 1 to 4 carbon atoms. Particularly preferred flavonols include galangin, kaempferol, iso-rhamnetin, quercetin and morin.</p> |