Format

Send to

Choose Destination
Mol Plant Microbe Interact. 2019 Jan 7:MPMI06180174R. doi: 10.1094/MPMI-06-18-0174-R. [Epub ahead of print]

Transcriptomic Analysis With the Progress of Symbiosis in 'Crack-Entry' Legume Arachis hypogaea Highlights Its Contrast With 'Infection Thread' Adapted Legumes.

Author information

1
1 Department of Biochemistry, University of Calcutta, Kolkata 700019, India.
2
2 LSTM, Univ. Montpellier, CIRAD, INRA, IRD, SupAgro, Montpellier, France; and.
3
3 Montpellier GenomiX (MGX), c/o Institut de Génomique Fonctionnelle, 141 rue de la cardonille, 34094 Montpellier Cedex 05, France.

Abstract

In root-nodule symbiosis, rhizobial invasion and nodule organogenesis is host controlled. In most legumes, rhizobia enter through infection threads and nodule primordium in the cortex is induced from a distance. But in dalbergoid legumes like Arachis hypogaea, rhizobia directly invade cortical cells through epidermal cracks to generate the primordia. Herein, we report the transcriptional dynamics with the progress of symbiosis in A. hypogaea at 1 day postinfection (dpi) (invasion), 4 dpi (nodule primordia), 8 dpi (spread of infection in nodule-like structure), 12 dpi (immature nodules containing rod-shaped rhizobia), and 21 dpi (mature nodules with spherical symbiosomes). Expression of putative ortholog of symbiotic genes in 'crack entry' legume A. hypogaea was compared with infection thread-adapted model legumes. The contrasting features were i) higher expression of receptors like LYR3 and EPR3 as compared with canonical Nod factor receptors, ii) late induction of transcription factors like NIN and NSP2 and constitutive high expression of ERF1, EIN2, bHLH476, and iii) induction of divergent pathogenesis-responsive PR-1 genes. Additionally, symbiotic orthologs of SymCRK, ROP6, RR9, SEN1, and DNF2 were not detectable and microsynteny analysis indicated the absence of a RPG homolog in diploid parental genomes of A. hypogaea. The implications are discussed and a molecular framework that guides crack-entry symbiosis in A. hypogaea is proposed.

PMID:
30109978
DOI:
10.1094/MPMI-06-18-0174-R

Supplemental Content

Full text links

Icon for Atypon
Loading ...
Support Center