Genetic engineering of harvest index in tobacco through overexpression of a phytochrome gene

Nat Biotechnol. 1996 Aug;14(8):995-8. doi: 10.1038/nbt0896-995.


The phytochrome photoreceptor family regulates plant architecture in response to environmental light signals. Phytochromes mediate the shade avoidance syndrome, in which plants react to far-red radiation reflected from neighbors by elongation growth, occurring at the expense of leaf and storage organ production. We show that transgenic overproduction of phytochrome A in tobacco suppresses shade avoidance, causing proximity-conditional dwarfing. At high densities in the field, assimilates show an enhanced allocation to leaves, with a concomitant increase in harvest index. Transfer of this approach to other crop plants could provide significant improvements in productivity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biotechnology
  • Ecology
  • Phenotype
  • Phytochrome / genetics*
  • Phytochrome A
  • Plants, Genetically Modified
  • Plants, Toxic*
  • Protein Engineering*
  • Tobacco / genetics*


  • Phytochrome A
  • Phytochrome