A wheat defence related miRNA targets a WRKY-domain containing NLR
V. NICOLIS (1), E. Venter (1) (1) University of Johannesburg, South Africa

Diuraphis noxia (Kurdjumov) is an economically important pest of wheat and barley in many countries including South Africa. Crop yields are negatively affected during aphid infestation due to chlorosis and necrosis of the leaves, eventually leading to the death of susceptible cultivars. The effective use of resistant wheat cultivars is being undermined by the emergence of resistance breaking D. noxia biotypes, which threaten the cultivation of wheat. The aim of this study was to characterise a defence related miRNA in the wheat-RWA interaction. Tae-miR-7757, the mature form of a miRNA isolated from a defence response enriched wheat cDNA library, putatively targets a number of CC-nucleotide-binding leucine-rich repeats. A total of 36 putative targets in the wheat genome were identified with a miRNA binding site in the NB-ARC domain, including a 5AL NLR that contains a C-terminal WRKY integrated domain. Knockdown of this gene using VIGS resulted in a susceptible phenotype in response to RWA-SA1. The expression pattern of tae-miR-7757 and this gene of interest were further compared in both a susceptible and resistant cultivar using RT-qPCR analysis, indicating that both are regulated in response to aphid infestation. This study provides a basis to further characterise ncRNA regulation linked to wheat-aphid interactions that will assist in deciphering the complex interplay between plant hosts and the pests that prey on them.

Abstract Number: P17-578
Session Type: Poster