Recently, I hassled people until they gave me places to look for lists of genes expressed in response to drought treatment in Helianthus. Perhaps you will find it useful too?

Marchand et al. 2014 drought gene regulatory network: http://onlinelibrary.wiley.com/doi/10.1111/nph.12818/full.

Based on experimental data from Rengel et al. 2012: http://dx.plos.org/10.1371/journal.pone.0045249

And more in Marchand’s thesis: http://thesesups.ups-tlse.fr/2597/

Additionally, Min has some data/preliminary analysis from a microarray study in sunflower. Contact him for more info?