New Phytol. 2024 Jun 05.
Nadim Tayeh,
Julie M I Hofer,
Grégoire Aubert,
Françoise Jacquin,
Lynda Turner,
Jonathan Kreplak,
Pirita Paajanen,
Christine Le Signor,
Marion Dalmais,
Stéphanie Pflieger,
Valérie Geffroy,
Noel Ellis,
Judith Burstin.
The afila (af) mutation causes the replacement of leaflets by a branched mass of tendrils in the compound leaves of pea - Pisum sativum L. This mutation was first described in 1953, and several reports of spontaneous af mutations and induced mutants with a similar phenotype exist. Despite widespread introgression into breeding material, the nature of af and the origin of the alleles used remain unknown. Here, we combine comparative genomics with reverse genetic approaches to elucidate the genetic determinants of af. We also investigate haplotype diversity using a set of AfAf and afaf cultivars and breeding lines and molecular markers linked to seven consecutive genes. Our results show that deletion of two tandemly arranged genes encoding Q-type Cys(2)His(2) zinc finger transcription factors, PsPALM1a and PsPALM1b, is responsible for the af phenotype in pea. Eight haplotypes were identified in the af-harbouring genomic region on chromosome 2. These haplotypes differ in the size of the deletion, covering more or less genes. Diversity at the af locus is valuable for crop improvement and sheds light on the history of pea breeding for improved standing ability. The results will be used to understand the function of PsPALM1a/b and to transfer the knowledge for innovation in related crops.
Keywords: PALMATE‐LIKE PENTAFOLIATA (PALM) genes; afila (af) mutation; breeding history; compound leaf morphology; introgressed haplotypes; legume; megabase‐scale deletion; pea (Pisum sativum L.)