To investigate whether this regulation at the transcriptional level was also found in other legume species, we queried the expression of genes in the Smirnoff-Wheeler pathway in the Medicago Gene Atlas database 6 (Benedito et al., 2008), which has been now extended with expression **data** corresponding to a progressive drought stress followed by a recovery treatment . In terms of drought responses, M. truncatula showed a differential response compared to soybean (Supplementary Figure 1). For instance, in leaves progressive drought caused a gradual increase in the expression of one of the GME genes, Medtr7g115080, while the levels VTC1 gene Medtr5g080770 and the regulatory gene VTC3 (Medtr1g050520) were reduced compared to well-watered plants. Interestingly, in roots drought induced the expression of the same GME gene observed in leaves, along with the VTC2 gene Medtr5g093390, while there was a reduction of the transcript levels of the two VTC1 genes (Supplementary Figure 1). It is worth noting that the two genes putatively coding for GME show an opposite pattern of expression both in roots and in leaves, which suggests a functional specialization of the genes.