XVI International Botanical Congess
We are interest in understanding how parasitic Scrophulariaceae recognize and respond to host root signals in the rhizoshpere. When root tips of the hemiparasite Triphysaria versicolor are exposed to host root exudates in vitro, secondary haustoria develop within hours (see http://veghome.ucdavis.edu/yoder/yoderlab/ for time lapse animation of haustorium development). We isolated several hundred cDNAs differentially abundant in T.versicolor root tips shortly after exposure to the haustorial inducing factor 2,6 dimethoxybenzoquinone (DMBQ). Most of these genes are either not induced or suppressed, consistent with the phytotoxicity of DMBQ. The expression patterns of a few genes likely involved in host signal recognition and transduction will be discussed in detail.