Small kernel 501 ( <i>smk501</i> ) encodes the RUBylation activating enzyme E1 subunit ECR1 (E1 C‐TERMINAL RELATED 1) and is essential for multiple aspects of cellular events during kernel development in maize

RUBylation plays essential roles in plant growth and development through regulating Cullin-RING ubiquitin E3 ligase (CRL) activities the CRL-mediated protein degradations. However, function of kernel remains unclear. Through genetic molecular analyses a small 501 (smk501) mutant maize (Zea mays), we cloned smk501 gene, revealed its function, defined pathway seed development. Smk501 encodes activating enzyme E1 subunit ZmECR1 (E1 C-TERMINAL RELATED 1) protein. Destruction by mutation resulted less embryo endosperm cell number smaller size. The transcriptome proteome profiling, hormone evaluation proliferation observation that disturbing expression mainly affects pathways on signal transduction, cycle progression starch accumulation during In addition, zmaxr1 (Auxin resistant 1), another RUB subunit, also showed similar defects Double zmecr1 lead to empty pericarp phenotype. is novel regulatory affecting development, majorly functions modifying multiple cellular progresses.