Initiation of compatible wheat-Hessian fly interactions triggers the expression of a novel UDP-glycosyltransferase, MdesUGT1, in virulent Hessian fly larvae

Authors: Subramanyam, Subhashree; Nemacheck, Jill

Submitted to: Arthropod-Plant Interactions
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/4/2021
Publication Date: 4/19/2021
Citation: Subramanyam, S., Nemacheck, J.A. 2021. Initiation of compatible wheat-Hessian fly interactions triggers the expression of a novel UDP-glycosyltransferase, MdesUGT1, in virulent Hessian fly larvae. Arthropod-Plant Interactions (2021). 15:363-374 https://doi.org/10.1007/s11829-021-09816-6.
DOI: https://doi.org/10.1007/s11829-021-09816-6

Interpretive Summary: The Hessian fly is one of the most destructive insect pests of wheat worldwide, including the United States, causing severe economic losses. Although resistant wheat is the most economical and environmentally sound method of control, the emergence of virulent biotypes of the pest that can overcome the resistance is a threat to long-term protection of wheat. Hence, deciphering the molecular interactions between virulent larvae and susceptible wheat is the key to developing alternate strategies for effective management of this and other insect pests. From an ongoing project to identify Hessian fly genes that can influence its ability to survive on wheat we have identified 13 genes that produce enzymes (called “UGTs”) that play an important role in detoxification of plant chemicals that can negatively affect the larvae. Further, we characterized a novel UGT gene, MdesUGT1, and propose a critical role for this gene in the deteoxification of host wheat and nonhost plant (Brachypodium distachyon) chemicals produced as defense against the insect pest. Knowledge from these studies will help breeders and scientists devise innovative methods to ensure production of durable, resistant wheat cultivars to prevent large yield losses due to Hessian fly infestation.

Technical Abstract: Insect UDP-glycosyltransferases (UGTs) play an important role in detoxification of substrates such as plant allelochemicals by the process of glucosidation. Hessian fly (Mayetiola destructor), belonging to the order Diptera (Family: Cecidomyiidae), is a destructive pest of host wheat causing significant economic losses. In the current study, using the assembled genome, we identified thirteen genes in M. destructor that belong to the family of UGTs (MdesUGT). Expression profiling revealed differential expression of MdesUGT genes in Hessian fly feeding instars. Further, we report the molecular cloning of MdesUGT1, designated as UGT301F1, from M. destructor. Characterization of the MdesUGT1 amino acid sequence revealed a conserved signature motif and sugar donor-binding domains characteristic of UGT proteins. Further expression analysis revealed dramatic increase in transcript accumulation of MdesUGT1 in the first and second feeding instars during compatible interactions (susceptible wheat, virulent larvae) but lacked significant expression during incompatible wheat Hessian fly interactions. Similar increase in MdesUGT1 transcripts was also observed during interactions of Hessian fly with nonhost, Brachypodium distachyon. These findings suggest the possible involvement of MdesUGT1 in detoxification of plant toxins, thus contributing to the growth and development of this dipteran insect pest. Identification and characterization of insect UGTs could provide valuable insights into the detoxification mechanisms and facilitate future plant pest management strategies.