Delay of leaf senescence in Medicago sativa transformed with the ipt gene controlled by the senescence-specific promoter SAG12.

We report the successfull delay of leaf senescence in Medicago sativa. A highly regenerable clone of alfalfa was transformed with the construct SAG12-IPT, an approach that has already proved efficient in other crops. Several independent transformants were obtained as determined by Southern analysis and all the transformants expressed the transgene as measured by RT-PCR.

Light and an exogenous transcription factor qualitatively and quantitatively affect the biosynthetic pathway of condensed tannins in Lotus corniculatus leaves.

The effects of increasing light and of a heterologous bHLH transcription factor on the accumulation of condensed tannins (CT) were investigated in leaves of Lotus corniculatus, a model legume species which accumulates these secondary metabolites in leaves as well as reproductive tissues. Light and expression of the transgene increased the level of CT in a synergistic way. To monitor how the changes in accumulation of condensed tannins were achieved, the level of expression of four key genes in the flavonoid pathway was estimated by real-time RT-PCR analysis.