A gene encoding maize caffeoyl-CoA O-methyltransferase confers quantitative resistance to multiple pathogens

Abstract

Alleles that confer multiple disease resistance (MDR) are valuable in crop improvement, although the molecular mechanisms underlying their functions remain largely unknown. A quantitative trait locus, qMdr, associated with resistance to three important foliar maize diseases-southern leaf blight, gray leaf spot and northern leaf blight-has been identified on maize chromosome 9. Through fine-mapping, association analysis, expression analysis, insertional mutagenesis and transgenic validation, we demonstrate that ZmCCoAOMT2, which encodes a caffeoyl-CoA O-methyltransferase associated with the phenylpropanoid pathway and lignin production, is the gene within qMdr conferring quantitative resistance to both southern leaf blight and gray leaf spot. We suggest that resistance might be caused by allelic variation at the level of both gene expression and amino acid sequence, thus resulting in differences in levels of lignin and other metabolites of the phenylpropanoid pathway and regulation of programmed cell death.

Fungal resistance mediated by maize wall‐associated kinase ZmWAK‐RLK1 correlates with reduced benzoxazinoid content

“…The gene Caffeoyl‐CoA O‐methyltransferase 2 ( ZmCCoAOMT2 ) is a key functional gene in the lignin metabolic pathway and upregulated (> five‐fold) when ZmWAK‐RLK1 is present before pathogen inoculation. Recently, this gene was shown to be associated with resistance against multiple foliage diseases including NCLB (Yang et al ., ), suggesting a link between ZmWAK‐RLK1 , lignin and NCLB resistance. Because c .…”

“…The gene Caffeoyl-CoA O-methyltransferase 2 (ZmCCoAOMT2) is a key functional gene in the lignin metabolic pathway and upregulated (> five-fold) when ZmWAK-RLK1 is present before pathogen inoculation. Recently, this gene was shown to be associated with resistance against multiple foliage diseases including NCLB (Yang et al, 2017a), suggesting a link between ZmWAK-RLK1, lignin and NCLB resistance. Because c. 50% of DEGs showed differential expression even before pathogen infection, this suggests a constitutive ZmWAK-RLK1-mediated immune response that might be expressed independently of the recognition of Fig.…”

Ethylene signaling regulates natural variation in the abundance of antifungal acetylated diferuloylsucroses and Fusarium graminearum resistance in maize seedling roots

“…Specialized metabolic pathways that give rise to diverse arsenals of bioactive defense compounds allow plants to fend off pathogen attacks. The significance of plant specialized metabolism in agriculture is exemplified by the association of specific biosynthetic genes with resistance against insect pests and phytopathogens (Meihls et al, 2013;Handrick et al, 2016;Yang et al, 2017). Such studies highlight the potential of enlisting naturally occurring specialized metabolites in crop species to enhance quantitative disease resistance.…”

Mapping quantitative trait loci associated with southern leaf blight resistance in maize (Zea mays L.)

“…Similarly, SLB QTL identified in bin 9.03/9.02 have been identified in three previous studies using population derived from different crosses (Belcher et al, ; Negeri et al, ; Zwonitzer et al, ). Yang et al () identified qMdr 9.02 localized on maize chromosome 9, associated with resistance to three important foliar maize diseases: SLB, gray leaf spot and northern leaf blight. The unique SLB resistance‐related QTL in bins 1.06, 4.01, 6.01 and 9.02 were detected by Li et al () in the environments of the United States and China.…”