title: Genome-wide analysis of expansin superfamily in wild Arachis discloses a stress-responsive expansin-like B gene.
abstract: Expansins are plant cell wall-loosening proteins involved in adaptive responses to environmental stimuli and various developmental processes. The first genome-wide analysis of the expansin superfamily in the Arachis genus identified 40 members in A. duranensis and 44 in A. ipaënsis, the wild progenitors of cultivated peanut (A. hypogaea). These expansins were further characterized regarding their subfamily classification, distribution along the genomes, duplication events, molecular structure, and phylogeny. A RNA-seq expression analysis in different Arachis species showed that the majority of these expansins are modulated in response to diverse stresses such as water deficit, root-knot nematode (RKN) infection, and UV exposure, with an expansin-like B gene (AraEXLB8) displaying a highly distinct stress-responsive expression profile. Further analysis of the AraEXLB8 coding sequences showed high conservation across the Arachis genotypes, with eight haplotypes identified. The modulation of AraEXLB8 expression in response to the aforementioned stresses was confirmed by qRT-PCR analysis in distinct Arachis genotypes, whilst in situ hybridization revealed transcripts in different root tissues according to the stress imposed. The overexpression of AraEXLB8 in soybean (Glycine max) composite plants remarkably decreased the number of galls in transformed hairy roots inoculated with RKN. This study improves the current understanding of the molecular evolution, divergence, and gene expression of expansins in Arachis, and provides molecular and functional insights into the role of expansin-like B, the less-studied plant expansin subfamily.
authors.affiliation: Embrapa Recursos Genéticos e Biotecnologia, Parque Estação Biológica, Final W5 Norte, Brasília, DF, CP 02372, Brazil.
authors.forename: Larissa Arrais
authors.initials: LA
authors.lastname: Guimaraes
authors.affiliation: Embrapa Recursos Genéticos e Biotecnologia, Parque Estação Biológica, Final W5 Norte, Brasília, DF, CP 02372, Brazil.|Universidade do Rio Grande do Sul, Porto Alegre, RS, Brazil.
authors.forename: Ana Paula Zotta
authors.initials: APZ
authors.lastname: Mota
authors.affiliation: Embrapa Recursos Genéticos e Biotecnologia, Parque Estação Biológica, Final W5 Norte, Brasília, DF, CP 02372, Brazil.
authors.forename: Ana Claudia Guerra
authors.initials: ACG
authors.lastname: Araujo
authors.affiliation: Universidade de Brasília, Campus Darcy Ribeiro, Brasília, DF, Brazil.
authors.forename: Lucio Flavio
authors.initials: LF
authors.lastname: de Alencar Figueiredo
authors.affiliation: Embrapa Recursos Genéticos e Biotecnologia, Parque Estação Biológica, Final W5 Norte, Brasília, DF, CP 02372, Brazil.|Universidade de Brasília, Campus Darcy Ribeiro, Brasília, DF, Brazil.
authors.forename: Bruna Medeiros
authors.initials: BM
authors.lastname: Pereira
authors.affiliation: Embrapa Recursos Genéticos e Biotecnologia, Parque Estação Biológica, Final W5 Norte, Brasília, DF, CP 02372, Brazil.
authors.forename: Mario Alfredo
authors.initials: MA
authors.lastname: de Passos Saraiva
authors.affiliation: Embrapa Recursos Genéticos e Biotecnologia, Parque Estação Biológica, Final W5 Norte, Brasília, DF, CP 02372, Brazil.|Universidade de Brasília, Campus Darcy Ribeiro, Brasília, DF, Brazil.
authors.forename: Raquel Bispo
authors.initials: RB
authors.lastname: Silva
authors.affiliation: Institut Sophia Agrobiotech, INRA, University of Nice Sophia Antipolis, CNRS, 06900, Sophia Antipolis, France.
authors.forename: Etienne G J
authors.initials: EGJ
authors.lastname: Danchin
authors.affiliation: Embrapa Recursos Genéticos e Biotecnologia, Parque Estação Biológica, Final W5 Norte, Brasília, DF, CP 02372, Brazil.
authors.forename: Patricia Messenberg
authors.initials: PM
authors.lastname: Guimaraes
authors.affiliation: Embrapa Recursos Genéticos e Biotecnologia, Parque Estação Biológica, Final W5 Norte, Brasília, DF, CP 02372, Brazil. ana.brasileiro@embrapa.br.
authors.forename: Ana Cristina Miranda
authors.initials: ACM
authors.lastname: Brasileiro
mesh_terms: D010367:Arachis / Q000235:genetics*; D002473:Cell Wall / Q000502:physiology; D018506:Gene Expression Regulation, Plant / Q000502:physiology*; D055106:Genome-Wide Association Study; D005810:Multigene Family / Q000502:physiology*; D010802:Phylogeny; D059828:Plant Cells / Q000502:physiology; D010935:Plant Diseases / Q000382:microbiology; D010940:Plant Proteins / Q000235:genetics*; D013312:Stress, Physiological / Q000235:genetics*; D014466:Ultraviolet Rays; D014867:Water
chemical_list: D010940:Plant Proteins; C095825:expansin protein, plant; D014867:Water
keywords: Composite plant; Drought; Glycine max; Meloidogyne; Ultraviolet (UV)