Transgenic fiber producing plants with increased expression of sucrose phosphate synthase

A method of increasing in a cotton plant the tolerance of photosynthetic efficiency to cool night temperatures measured by CO2 consumption, comprising:

• introducing into a cotton plant a chimeric DNA construct comprising a plant specific promoter and a DNA encoding a sucrose phosphate synthase, said DNA construct expressing sucrose phosphate synthase and increasing sucrose phosphate synthase activity relative to a non-transgenic cotton plant in an amount sufficient to increase tolerance of photosynthetic efficiency to cool night temperatures in the transgenic cotton plant relative to a non-transgenic cotton plant.

A method of increasing the thickness of cell walls in a cotton plant, comprising:

• introducing into a cotton plant a chimeric DNA construct comprising a plant specific promoter and a DNA encoding a sucrose phosphate synthase, said DNA construct expressing sucrose phosphate synthase and increasing sucrose phosphate synthase activity relative to a non-transgenic cotton plant in an amount sufficient to increase the thickness of cell walls in the transgenic cotton plant relative to a non-transgenic plant.