Work

Mutation and sequencing‐based cloning and functional studies of a rust resistance gene in sunflower (Helianthus annuus)

Year: 2023

Type: article

Abstract: SUMMARY Rust, caused by the fungus Puccinia helianthi Schwein., is one of the most devastating diseases of sunflower (Helianthus annuus L.), affecting global production. The rust R gene R11 in sunflower line HA‐R9 shows broad‐spectrum resistance to P. helianthi virulent races and was previously mapped to an interval on sunflower chromosome 13 encompassing three candidate genes annotated in the XRQr1.0 reference genome assembly. In the current study, we combined ethyl methane sulfonate (EMS) mutagenesis with targeted region capture and PacBio long‐read sequencing to clone the R11 gene. Sequencing of a 60‐kb region spanning the R11 locus from the R11‐HA‐R9 rust‐resistant line and three EMS‐induced susceptible mutants facilitated the identification of R11 and definition of induced mutations. The R11 gene is predicted to have a single 3996‐bp open reading frame and encodes a protein of 1331 amino acids with CC‐NBS‐LRR domains typical of genes conferring plant resistance to biotrophic pathogens. Point mutations identified in the R11 rust‐susceptible mutants resulted in premature stop codons, consistent with loss of function leading to rust susceptibility. Additional functional studies using comparative RNA sequencing of the resistant line R11‐HA‐R9 and R11‐susceptible mutants revealed substantial differences in gene expression patterns associated with R11‐mediated resistance at 7 days post‐inoculation with rust, and uncovered the potential roles of terpenoid biosynthesis and metabolism in sunflower rust resistance.

Source: The Plant Journal

DOI: 10.1111/tpj.16238

Authors: Md Shamimuzzaman, Guojia Ma, William Underwood, Lili Qi

Institutions: Agricultural Research Service, United States Department of Agriculture, Edward T. Schafer Agricultural Research Center, North Dakota State University

Language: English

Topic: Plant Disease Resistance and Genetics

Subfield: Plant Science

Field: Agricultural and Biological Sciences

Domain: Life Sciences

SDG: Zero hunger

Open Access status: hybrid

Estimated APC paid: $4,940