Modification in indole-3-acetic acid metabolism, growth and development of strawberry through transformation with maize IAA-glucose synthase gene (iaglu)

Abstract

Strawberry (Fragaria × ananassa Duch.) was transformed with maize IAA-glucose synthase gene (iaglu) via Agrobacterium tumefaciens using binary vector system. Incorporation of the transgene was confirmed by PCR and Southern blot analysis and its transcription by RT-PCR. Transformation resulted in a significant increase of ester-conjugated IAA level in tissue of all tranegenic plants while free IAA level was significantly lower in two trangenic clones tested and in other two it was comparable to that in wild-type plants. The level of amide-conjugated hormone was not affected by transformation with iaglu. The change in endogenous IAA metabolism affected the growth and development of transgenic strawberry plants but the effect was not fully correlated with changes in endogenous IAA level. In general, the transgenic clones were dwarfish — their leaf laminas were smaller, leaf petioles shorter and the crown diameter smaller in comparison to wild-type ones, although in one clone the difference was significant only for leaf lamina area. Shoots of all transgenic clones formed more roots in vitro than the wild-type plants and in two clones the roots were longer than in the control.