Using the lens of molecular plant-microbe interactions to uncover the pathways of plant parasitization by the parasitic weed Phelipanche aegyptiaca (broomrape). 
C. CLARKE (1), J. Westwood (1) (1) Virginia Tech, U.S.A.

Parasitic plants in the family Orobanchaceae, including witchweed Striga hermonthica and broomrape Phelipanche aegyptiaca, are the leading biotic constraints on agricultural production in many locations in Africa, Asia and eastern Europe.  Parasitic weeds, like microbial plant pathogens, must interact closely with host plants to extract nutrients and suppress defense responses. We are studying the parasitic plant P. aegyptiaca through the lens of molecular plant-microbe interactions to elucidate host-parasite interactions. We have screened over 40 Arabidopsis mutants defective in known aspects of immune responses against other classes of plant pathogens for altered resistance to virulent P. aegyptiaca. We are also identifying non-host Orobanchaceae to screen for increased susceptibility of these Arabidopsis mutants. Jasmonic acid signaling-associated and DELLA genes have been identified as essential for full susceptibility of Arabidopsis to P. aegyptiaca. Additionally, we have performed RNA sequencing on Arabidopsis parasitized by P. aegyptiaca at several developmental stages to get a preliminary list of host genes that have altered expression profiles due to parasitization. Finally, we have cloned over 30 candidate secreted proteins from P. aegyptiaca. These proteins are candidate effectors with some showing putative immune-suppression function. These experiments are a first step of synthesizing knowledge of parasitic plants with other classes of plant pathogens.

Abstract Number: C21-2, P19-708
Session Type: Concurrent