Ethylene response factor (ERF) proteins constitute a major branch of the AP2/ERF transcription factor superfamily and are conventionally divided into six groups (B1–B6) on the basis of conserved sequences and phylogenetic relationships. ERFs recognize cis-elements such as the GCC-box and dehydration-responsive element/C-repeat and assemble regulatory complexes with coactivators or corepressors. They thereby coordinate responses to drought, salinity, low and high temperatures, hypoxia, flooding, and pathogen attack. Their outputs are determined not by a single motif but by DNA-binding preference, interacting partners, tissue context, and post-translational control through mitogen-activated protein kinase phosphorylation, ubiquitination, and the N-degron pathway. Crop studies increasingly show that ERF alleles and regulatory modules can improve stress tolerance and disease resistance, although constitutive manipulation frequently compromises growth, yield, or quality. This review focuses on the narrowly defined ERF subfamily, evaluates the evidence linking classification, transcriptional regulation, protein stability, and stress phenotypes, and examines breeding strategies based on molecular markers, tissue-specific expression, cis-regulatory editing, and favorable alleles. We argue that progress now depends on causal analysis under combined stresses and multi-environment yield validation, enabling stress protection to be decoupled from agronomic penalties.

SUMMARY: Precise regulation of flowering time and maturity is critical for achieving high and stable soybean yields, and the circadian clock plays a central role in coordinating these developmental transitions. Soybean is a typical short‐day crop with a pronounced photoperiodic response; however, the molecular mechanisms linking circadian regulation to photoperiod‐dependent flowering and maturity remain incompletely understood. Here, we integrated genome‐wide association analysis with deep learning approaches using 257 soybean germplasm accessions spanning 14 maturity groups and identified GmRVE8a , a homolog of the Arabidopsis circadian clock gene REVEILLE , as a strong candidate locus associated with soybean maturity across two field environments. Haplotype analysis demonstrated that accessions carrying the GmRVE8a ^H1 haplotype consistently flowered and matured significantly later than those carrying GmRVE8a ^H2 . Functional validation revealed that knockout of GmRVE8a markedly accelerated flowering and maturity, whereas overexpression of GmRVE8a significantly delayed both processes. qRT‐PCR assays further suggested that GmRVE8a may repress flowering and delay maturity by promoting the expression of GmFT4 , a flowering‐inhibitory member of the FT family, and is unlikely to act by directly regulating E1 expression. Collectively, our findings suggest GmRVE8a as a circadian clock‐associated negative regulator of soybean flowering and maturity, and highlight it as a promising candidate for molecular breeding aimed at improving adaptation to diverse photoperiodic environments.

Soybean (Glycine max) is a critically important crop for oil, protein, feed, and food security in China. Expanding soybean cultivation into high-latitude regions represents one of the most direct and effective strategies to increase total production. In the present study, we employed KASP (Kompetitive Allele-Specific PCR) marker technology to systematically analyze 18 variant loci across 14 flowering-time genes in 443 soybean germplasm accessions adapted to high-latitude conditions in Arctic Village (Beiji Cun), Mohe City (>53° N), northeastern China. Our results revealed clear functional-tier-dependent selection gradients: key mutation sites (frequency > 96%) in upstream photoreceptors and core circadian clock genes, such as E2 and GmPRR3a, were nearly fixed in the population, whereas downstream flowering genes such as GmFT5b and GmFT2b remained under dynamic selection. Combinatorial analysis of early-maturity allelic variants identified 178 distinct genotype combinations, including six dominant types (n ≥ 10). Field phenotypic analysis demonstrated that the cumulative number of early-maturity alleles was significantly negatively correlated with flowering time, with specific allele combinations such as FT5a^A + FKF1b-hap3^T exhibiting particularly strong flower-promoting effects. A set of 80 highly enriched super-early-maturity accessions, including extreme materials such as MHL22002, were identified, providing valuable genetic resources and a theoretical framework for elucidating the flowering regulatory mechanisms of high-latitude soybean and for breeding super-early-maturing varieties.