Objective:
Objectives for Project Title: Engineering Scab Resistance in Wheat with Plant Defense Signaling Genes - (1) Evaluate Scab resistance in AtPAD4 expressing wheat and (2) Engineer AtWRKY18 expression in wheat. Objectives for projects transfered from ARS agreement with KSU: Project Title 1: Engineering Scab Resistance in Wheat with Defense Signaling Genes - (1) Continue our efforts to transform and characterize AtNPR1 expressing durum cultivars and (2) Engineer AtPAD4 expression in wheat. Project Title 2: Signaling Mechanism in Host Defense and Susceptibility to Fusarium graminearum - (1) Further characterization of SA's involvement in plant defense against F. graminearum and (2) Further characterization of the involvement of JA as a susceptability factor in plant interaction with F. graminearum.

Approach:
Approach for Project Title: Engineering Scab Resistance in Wheat with Plant Defense Signaling Genes - (1) We will evaluate transgene expression and scab resistance in Ubi:AtPAD4 transformed transgenic plants and (2) The AtWRKY18 cDNA will be cloned under the control of the maize Ubi promoter, and the resulting Ubi:AtWRKY18 construct will be transformed into hexaploid wheat. We will evaluate transgene expression in the transgenic plants. In ensuing years, we will test scab resistance in promising lines. Approach for projects transfered from ARS agreement with KSU: Project Title 1: Engineering Scab Resistance in Wheat with Defense Signaling Genes - (1) We will continue our efforts to transform the Ubil:AtNPR1 construct into durum cultivars. In addition, we will evaluate transgene expression and scab resistance in the transgenic durum wheat plants that have already been generated. (2) The AtPAD4 cDNA will be cloned under the control of a maize Ubil promoter, and the resulting Ubil:AtPAD4 construct will be transformed into a hexaploid wheat. We will evaluate transgene expression and the level of the chimeric AtPAD4 protein in the transgenic plants. In ensuing years, we will test scab resistance in promising lines. Project Title 2: Signaling Mechanism in Host Defense and Susceptibility to Fusarium graminearum - (1) Multiple approaches will be taken: (a) Transgenic wheat expressing the SA degrading salicylate hydoxylase encoded by nahG will be developed. These plants will provide the genetic tools necessary for future experimentations to characterize the involvement of SA in wheat resistance to F. graminearum and (b) A regulatory WRKY gene that is a target of AtNPR1 will be characterized for its role in plant defense against F. graminearum; (2) A combination of genetic and biochemical approaches will be taken to determine if JA antagonizes SA signaling in Arabidopsis and wheat interaction with F. graminearum, thereby contributing to susceptibility to the fungus.