Comparative genomic analysis reveals the difference of NLR immune receptors between anthracnose-resistant and susceptible sorghum cultivars

Abstract Anthracnose, caused by Colletotrichum sublineola, is a prevalent disease that noticeably affects global sorghum production. Nucleotide-binding leucine-rich repeat receptors (NLRs) are crucial for disease resistance. Here, we report the differences in the number, expression profile, and gene structure of NLRs between the anthracnose-resistant and susceptible sorghum cultivars. Through a systematic anthracnose disease assay on 365 sorghum accessions, we identified the American improved cultivar BTx623 as the resistant and the Chinese improved glutinous cultivar Guojiaohong1 (GJH1) as the susceptible cultivar. Then we sequenced the genome of GJH1 and identified 239 NLRs, substantially fewer than the 302 in BTx623. Although the collinear NLRs are highly conserved between GJH1 and BTx623, more than half of the non-collinear NLRs showed notable mutations or structural variations. During C. sublineola infection, BTx623 exhibited a higher number of highly expressed and inducible NLR genes than GJH1 did. Moreover, we identified some candidate anthracnose resistance genes that are potentially valuable for disease-resistant breeding. Therefore, our data provide genetic resources for developing disease-resistant glutinous sorghum.