Transcriptome profiles reveal gene regulation of peanut (Arachis hypogaea L.) nodulation

Abstract

The molecular mechanisms of symbiosis in cultivated peanut with a ‘crack entry’ infection process are largely understudied. In this study, we investigated the root transcriptional profiles of two pairs of non-nodulating (nod−) and nodulating (nod+) sister inbred peanut lines, E4/E5 and E7/E6, and their nod+ parents, F487A and PI262090 during rhizobial infection and nodule initiation by using RNA-seq technology. A total of 143, 101, 123, 215, 182, and 289 differentially expressed genes (DEGs) were identified in nod− E4, E7 and nod+ E5, E6, F487A, and PI262090 after inoculation with Bradyrhizobium sp. Different deficiencies at upstream of symbiotic signaling pathway were revealed in the two nod− genotypes. DEGs specific in nod+ genotypes included orthologs to some known symbiotic signaling pathway genes, such as NFR5, NSP2, NIN, ERN1, and many other novel and/or functionally unknown genes. Gene ontology (GO) enrichment analysis of nod+ specific DEGs revealed 54 significantly enriched GO terms, including oxidation-reduction process, metabolic process, and catalytic activity. Genes related with plant defense systems, hormone biosynthesis and response were particularly enriched. To our knowledge, this is the first report revealing symbiosis-related genes in a genome-wide manner in peanut representative of the ‘crack entry’ species.

Auxin signalling of Arachis hypogaea activated by colonization of mutualistic fungus Phomopsis liquidambari enhances nodulation and N2 -fixation

“…To investigate the roles of auxin signalling in P. liquidambari ‐mediated activation of nodulation signalling, transcriptional response of key nodulation signalling genes SymRK , CCaMK , and early nodulin genes NIN and ENOD40 were examined at 5 and 10 dai. These two time points were chosen as nodule primordium was first observed at 10 dai in our system, and thus symbiotic signalling pathway was presumably activated in the root at 5 dai (Peng et al, ; L. Zhang, Xu, et al, ). The relative expression of all tested genes was up‐regulated in P. liquidambari and bradyrhizobium coinoculated roots compared with bradyrhizobium only inoculation roots (Figure a–d).…”

“…Recently, a transcriptome study showed that auxin metabolism and responses of peanut are modulated in response to bradyrhizobial invasion (Peng et al, ). However, no detail study has determined whether auxin is required for peanut–bradyrhizobium symbiosis.…”

“…Total RNA was isolated from the peanut crown root nodulation zone (Peng et al, ) using the Trizol reagent, according to the manufacturer's instructions. To eliminate the genomic DNA contamination, RNA samples were incubated with RNase‐free DNase at 42 °C for 2 min.…”

Effectiveness and Limitations of Computational Chemistry and Mass Spectrometry in the Rational Design of Target‐specific Shift Reagents for Ion Mobility Spectrometry

“…In this section, we investigated 4,13‐diaza‐18‐crown 6 ether (Diaza18C6E) as SR for shifting the signal of perchlorate ions (ClO 4 − ). Perchlorate are anions of great interest in the field of explosives detection and environmental monitoring, which could justify the use of SR strategies for enhancing the reliability of its detection. Diaza18C6E is a crown ether‐related compound that has two secondary amino functional groups which can be protonated to form a doubly charged species.…”

Involvement of Root Hair during <i>Rhizobial</i> Invasion in Cultivated Peanut (<i>Arachis hypogaea</i> L.)

“…Bradyrhizobia strain LB8 [17] was first grown from glycerol stock on YEM plate supplemented with 25 µg/ml chloramphenicol. A single colony from the plate was then grown in YEM broth in 27˚C shaker at 200 rpm until OD 600 = 0.5 -1.5.…”