| tobacco plants carrying a tms locus of ti-plasmid origin and the hl-1 allele are tumor prone. | the autonomous growth of plant tumor cells is believed to result from their persistent loss of the requirement for growth hormones such as auxin and cytokinin. the partially dominant gene habituated leaf-1 (hl-1) regulates the requirement of cultures tissues of havana 425 tobacco (nicotiana tabacum l.) for cytokinins. the hl-1 allele can partially restore the tumor phenotype in tobacco cells transformed with a agrobacterium tumefaciens ti plasmid defective in the isopentenyl transferase locus, w ... | 1997 | 9203344 |