The PvAURK-PvGRFs regulatory module controls salt tolerance in common bean (Phaseolus vulgaris L.)

The common bean (Phaseolus vulgaris L.) is an important edible legume. However, the molecular mechanisms underlying its salt tolerance remain unclear. Here, we used a panel of 494 diverse common bean accessions and identified Aurora Kinase (AURK) as a key gene associated with salt tolerance using a genome-wide association study (GWAS). Functional validation demonstrated that PvAURK interacts with growth regulatory factors (GRF2 and GRF5) both in vivo and in vitro. All three genes positively regulate salt tolerance in common bean. Transcriptomic analysis showed that PvAURK modulates the salt stress response by regulating the reactive oxygen species (ROS) scavenging system via PvGRF transcription factors, with medium-chain-fatty-acid-[acyl-carrier-protein] ligase (MC-ACPL) and PTHR31388:SF157-PEROXIDASE (SF157-PRx) identified as downstream target genes of PvGRFs. Haplotype analysis showed that Hap2 of PvAURK is associated with enhanced salt tolerance. Key single nucleotide polymorphisms (SNPs) within these haplotypes strengthen the interactions between PvAURK and PvGRFs proteins. PvAURK Hap2 is the predominant salt-tolerant haplotype in natural common bean populations. This study elucidates the role of the PvAURK-PvGRF regulatory module in mediating salt tolerance in common bean. The developed KASP markers are efficient tools for marker-assisted breeding to improve salt tolerance.