SPO11.2 is essential for programmed double strand break formation during meiosis in bread wheat (Triticum aestivum L.) - INRAE - Institut national de recherche pour l’agriculture, l’alimentation et l’environnement Accéder directement au contenu
Article Dans Une Revue Plant Journal Année : 2020

SPO11.2 is essential for programmed double strand break formation during meiosis in bread wheat (Triticum aestivum L.)

Résumé

Meiotic recombination is initiated by formation of DNA double strand breaks (DSBs). This involves a protein complex that includes in plants the two similar proteins, SPO11-1 and SPO11-2. We analysed the sequences of SPO11-2 in hexaploid bread wheat (Triticum aestivum) as well as in its diploid and tetraploid progenitors. We investigated its role during meiosis using single, double and triple mutants. The three homoeologous SPO11-2 copies of hexaploid wheat exhibit high nucleotide and amino acid similarities with those of the diploids, tetraploids and Arabidopsis. Interestingly however, two nucleotides deleted in exon-2 of the A copy lead to a premature stop codon and suggest that it encodes a non-functional protein. Remarkably, the mutation was absent from the diploid A-relative T. urartu but present in the tetraploid T. dicoccoides and in different wheat cultivars indicating that the mutation occurred after the first polyploidy event and has since been conserved. We further show that triple mutants with all three copies (A, B, D) inactivated are sterile. Cytological analyses of these mutants show synapsis defects, accompanied by severe reductions in bivalent formation and numbers of DMC1 foci, thus confirming the essential role of TaSPO11-2 in meiotic recombination in wheat. In accordance with its 2-nucleotide deletion in exon-2, double mutants for which only the A copy remained are also sterile. Notwithstanding, some DMC1 foci remain visible in this mutant, suggesting a residual activity of the A copy, albeit not sufficient to restore fertility.
Fichier principal
Vignette du fichier
2020_Benyahya_Plant_Journal.pdf (972.23 Ko) Télécharger le fichier
2020_Benyahya_Figures_Plant_Journal.pdf (1.24 Mo) Télécharger le fichier

Dates et versions

hal-02888993 , version 1 (19-11-2020)

Identifiants

Citer

Fatiha Benyahya, Isabelle Nadaud, Olivier da Ines, Hélène Rimbert, Charles I. White, et al.. SPO11.2 is essential for programmed double strand break formation during meiosis in bread wheat (Triticum aestivum L.). Plant Journal, 2020, 104 (1), pp.30-43. ⟨10.1111/tpj.14903⟩. ⟨hal-02888993⟩
119 Consultations
205 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More