SPOROCYTELESS/NOZZLE interacts with MADS-DOMAIN transcription factors during the megaspore mother cell differentiation in the Arabidopsis ovule

ABSTRACT: This dataset contains proteomic data from co-immunoprecipitation and mass spectrometry (IP-MS) experiments performed to identify in planta interaction partners of the transcriptional regulator SPOROCYTELESS/NOZZLE (SPL) during Arabidopsis thaliana ovule development. SPL is an essential regulator of megaspore mother cell (MMC) specification, yet the protein complexes through which it acts remained largely unknown. To elucidate the SPL interactome, a pSPL:SPL-GFP fusion was expressed in the pAP1:AP1-GR ap1 cal floral inducible system, allowing synchronized flower development and enrichment of ovule stages preceding MMC formation. SPL-GFP protein complexes were isolated from inflorescences at early ovule developmental stages and analysed by LC-MS/MS. The IP-MS analysis revealed 660 proteins significantly enriched in SPL-GFP immunoprecipitates compared with input controls, providing the first comprehensive view of SPL-associated nuclear partners in reproductive tissues. Among transcription factors co-purifying with SPL, MADS-domain proteins were particularly prominent, representing about one fifth of all enriched TFs. These included SEEDSTICK (STK), SHATTERPROOF2 (SHP2), SEPALLATA1-3 (SEP1–3), and AGAMOUS (AG)—core components of the ovule identity regulatory network. The detection of these ovule-specific MADS-domain transcription factors among SPL interactors strongly supports a model in which SPL is recruited into multimeric MADS-domain complexes that coordinate nucellus development and MMC specification. The SPL IP-MS dataset therefore provides crucial insight into the protein interaction landscape controlling female germline initiation in Arabidopsis. It identifies SPL as a central component of ovule identity complexes and reveals a biochemical connection between SPL activity and the MADS-mediated transcriptional network that defines nucellar fate and auxin-dependent MMC differentiation.

INSTRUMENT(S):

ORGANISM(S): Arabidopsis Thaliana (mouse-ear Cress)

TISSUE(S): Flower

SUBMITTER: Cezary Smaczniak  

LAB HEAD: Kerstin Kaufmann

PROVIDER: PXD070409 | Pride | 2025-11-18

REPOSITORIES: Pride