Extreme specificity of NCR gene expression in Medicago truncatula

摘要: Legumes form root nodules to house nitrogen fixing bacteria of the rhizobium family. The rhizobia are located intracellularly in symbiotic nodule cells. In legume Medicago truncatula these cells produce high amounts Nodule-specific Cysteine-Rich (NCR) peptides which induce differentiation into enlarged, polyploid and non-cultivable bacterial NCRs similar innate immunity antimicrobial peptides. NCR gene family is extremely large with about 600 genes. Here we used Gene Expression Atlas (MtGEA) other published microarray data analyze expression 334 genes 267 different experimental conditions. We find that all but five expressed no plant organ or response any biotic interaction abiotic stress tested. During symbiosis, none induced by Nod factors. activated successive waves during organogenesis, correlated infection a specific spatial localization their transcripts from apical proximal zones. However, not associated senescence. According Shannon entropy, measure expressing tissue specificity expression, among most specifically M. truncatula. Moreover, when nodules, level highest Together, show subject an extreme tight regulation only organogenesis