Location: Northwest Irrigation and Soils ResearchTitle: Combined omics approaches reveal distinct mechanisms of resistance and/or susceptibility in sugar beet double haploid genotypes at early stages of beet curly top virus infection
Submitted to: International Journal of Molecular Sciences
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/7/2023
Publication Date: 10/9/2023
Citation: Galewski, P.J., Majumdar, R., Lebar, M.D., Strausbaugh, C.A., Eujayl, I.A. 2023. Combined omics approaches reveal distinct mechanisms of resistance and/or susceptibility in sugar beet double haploid genotypes at early stages of beet curly top virus infection. International Journal of Molecular Sciences. 24:15013. https://doi.org/10.3390/ijms241915013.
Interpretive Summary: Sugar beet is highly susceptible to Beet curly top virus (BCTV) which significantly reduces yield and overall sugar production. The severity of disease symptoms caused by BCTV primarily depends upon virus strain type and genetic background of sugar beets. Genetic mechanisms and the role of host plant metabolites in sugar beet resistance to BCTV is unknown. It is also not fully understood why some BCTV strains produce strong disease symptoms while others are unable to do such. Using BCTV resistant and susceptible sugar beet genotypes produced at Kimberly, Idaho (USDA-ARS), natural infection with beet leafhoppers carrying different virus strains, and combination of molecular and biochemical tools, we demonstrate potential roles of plant genes/metabolites in resistance and virus strain specific elements that could act as potential pathogenicity factors. The data presented here will help design precise mitigation strategies against BCTV and improve sugar yield in the future.
Technical Abstract: Sugar beet is highly susceptible to Beet curly top virus (BCTV) which significantly reduces yield and sugar production in the semi-arid growing regions worldwide. Sources of genetic resistance to BCTV is highly limited and primarily dependent upon seed treatment with neonicotinoids, the use of which is gradually being restricted. Through double haploid production and genetic selection, we have developed BCTV resistant breeding lines. Using BCTV resistant (R) [KDH13; Line 13, and KDH4-9; Line 4] and susceptible (S) [KDH19-17; Line 19] lines, beet leafhopper meditated natural infection, mRNA/sRNA sequencing, and metabolite analyses we demonstrate potential mechanisms of resistance against the virus. At early infection stages (2- and 6-days post inoculation), examples of differentially expressed genes highly up-regulated in the ‘R’ lines (vs. ‘S’) include EL10Ac5g10437 (inhibitor of trypsin and hageman factor), EL10Ac6g14635 (jasmonate induced protein), EL10Ac3g06016 (ribosome related), EL10Ac2g03119 (unknown) etc. Pathway enrichment analysis showed differentially expressed genes predominantly involved with peroxisome, amino acids metabolism, fatty acid degradation, amino/nucleotide sugar metabolism etc. Metabolite analysis revealed significantly higher amounts of isoflavonoid O-glycosides, flavonoid 8-C glycosides, triterpenoid, iridoid-O-glycosides in the leaves of the ‘R’ lines (vs. ‘S’). The data presented here suggest a combination of transcriptional regulation and production of antiviral metabolites might contribute to BCTV resistance. In addition, genome divergence among BCTV strains differentially affects the production of small non-coding RNAs (sncRNAs) and small peptides which may potentially affect pathogenicity and disease symptom development.