Abstract
Very few sources of resistance to Fusarium head blight (FHB) of wheat have been identified. Thinopyrum elongatum (Host) D.R. Dewey (2n = 14, EE genome), a wild relative of wheat, carries resistance to FHB on the long arm of its chromosome 7E (7EL). In this report, a strain of Fusarium graminearum Schwabe, the principal causal agent of FHB, transformed to produce green fluorescent protein (GFP), was used to characterize the resistance carried by 7EL when expressed in the susceptible background of 'Chinese Spring' (CS) wheat. Inoculated spikelets of the addition line CS-7EL showed less infection than those of the parental line, CS. This was associated in CS-7EL with upregulation of many genes predicted to be involved in plant defence and downregulation of genes associated with salicylic-acid-induced defence. The difference between CS and CS-7EL in the progression of infection was striking; the fungus spread easily and extensively from the inoculated spikelet into the node and adjacent spikelets in CS, but was effectively blocked from spreading in CS-7EL. Microscopic data showed that fungal growth was inhibited within the inoculated spikelet in CS-7EL, and spread was completely blocked by the node tissue. The blocking of fungal growth through the node into the rachis correlates with the deposition of an unidentified substance in CS-7EL. Additionally, longer internode segments in CS-7EL versus CS may contribute to limiting fungal spread. Our results suggest that the resistance displayed by CS-7EL is multifaceted, involving both physical and chemical factors.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.