InterPro-to-GO mappings (MADS-box IPR002100/IPR036879; K-box IPR002487; MEF2-like N IPR033896) assign DNA binding, DNA-binding transcription factor activity, sequence-specific Pol II regulatory-region DNA binding, protein dimerization activity, and (positive) regulation of transcription to OsMADS3 - all consistent with its MIKC-type MADS-box transcription-factor function.

The MADS-box/MEF2 phylogenetic group (GO_Central) supports OsMADS3 annotations to RNA polymerase II cis-regulatory region sequence-specific DNA binding and to regulation of transcription by RNA polymerase II.

SwissProt keyword-derived (SPKW) annotation present in the Sept 2025 goa_uniprot_gcrp snapshot but removed from the current GOA release after GOA retired the keyword2GO pipeline for cellular organisms.

For OsMADS3 the keyword "Differentiation" mapped to the generic "cell differentiation" (GO:0030154); the gene's real role is specifically floral-organ (stamen) identity specification, so the keyword term is over-coarse and is better replaced by the specific term GO:0010097.

ARBA ML models assigned the broad terms "post-embryonic development" and "reproductive structure development" to OsMADS3; these are correct in area but too generic relative to the gene's specific floral-organ-identity function.

Combined IEA methods assigned nuclear localization to OsMADS3, consistent with its function as a nuclear transcription factor.

Loss-of-function (antisense) analysis shows OsMADS3 is highly homologous to the AGAMOUS (AG) family; antisense OsMADS3 alters the third and fourth whorls, with stamen filaments changed into thick fleshy lodicule-like bodies, establishing OsMADS3 as a class C floral organ identity gene.

Ectopic (Actin1-promoter) expression of OsMADS3 homeotically transformed lodicules into stamens in 18 of 26 independent transgenic lines, the gain-of-function counterpart of the C-class stamen-identity role.

A T-DNA knockout of OSMADS3 shows homeotic transformation of stamens into lodicules and ectopic lodicules in the second whorl, while carpels develop almost normally; OSMADS3 and OSMADS58 are partially subfunctionalized rice AG paralogs controlling stamen identity, lodicule repression, and floral meristem determinacy.

Establishes that floral organ identity and meristem determinacy in rice are controlled by combinations of MADS-box gene activities; the cited reference for the AgBase TAS "specification of stamen identity" annotation, though it characterizes the AGL6-like gene OsMADS6/MFO1 rather than OsMADS3 directly.

OsMADS3 is the rice AGAMOUS-like C-class MIKC-type MADS-box transcription factor; with its paralog OsMADS58 it controls reproductive floral organ identity and floral meristem determinacy, and it plays the predominant role in repressing lodicule fate and specifying stamen identity.

Loss-of-function evidence (antisense silencing and the T-DNA allele osmads3-3) homeotically transforms almost all stamens into lodicule-like organs and causes meristem-determinacy defects; overexpression transforms lodicules into stamens.

OsMADS3 acts via DNA binding (MADS domain) and dimerization / higher-order MADS-complex (floral-quartet) assembly (K-box) with SEP-like (E-class) partners; it is functionally interpreted as acting in the nucleus.

OsMADS3 has a later, stage-specific role in late anther development through ROS homeostasis - it binds the MT-1-4b promoter and induces OsMT-I-4b to buffer ROS and promote tapetal programmed cell death, contributing to pollen fertility.