Auxin response factors (ARFs) are transcriptional factors that bind specifically to the DNA sequence 5'-TGTCTC-3' found in the auxin-responsive promoter elements (AuxREs) (By similarity). Could act as transcriptional activator or repressor (PubMed:26959229, PubMed:26716451, PubMed:27645097, PubMed:28167023). Involved in the control of fruit ripening process (PubMed:26959229, PubMed:26716451, PubMed:28167023). Regulates expression of a number of ripening regulators, transcription factors, and ethylene biosynthesis and signaling components (PubMed:26959229, PubMed:26716451). May act as a transcriptional repressor of auxin-responsive genes (PubMed:26716451). Regulates vegetative growth, lateral root formation and flower organ senescence, possibly partially by regulating gene expression of auxin and ethylene response factor (ERF) genes (PubMed:28167023). Plays a negative role in axillary shoot meristem formation (PubMed:27645097). Homodimers and heterodimers. Interacts with ASR1. Expressed in root, leaf and flower (PubMed:26716451, PubMed:27645097, PubMed:28167023, PubMed:21735233). Expressed in flower buds about three days before opening including ovary, petal and sepal with the highest in stamen (PubMed:21735233). Expressed in stem (PubMed:26716451, PubMed:28167023, PubMed:21735233). Expressed in fruit (PubMed:26716451, PubMed:27645097, PubMed:28167023). Expressed in seeds (PubMed:27645097). Expression increases at the orange (Or) and red (R) fruit stages. Expression is increased with ethylene at mature green (MG) stage, but only after six days post-treatment. Expression is increased three days post-treatment with plant hormone abscisic acid (ABA) at the Or stage, but not at the MG or breaker (Br) stages. No change in expression level up to six days post-treatment with ABA at the MG fruit stage (PubMed:26959229). Expressed during floral development (PubMed:21735233, PubMed:28167023, PubMed:27645097). During bud-anthesis stages flowers exhibit dynamic expression pattern in sepal, stamen, ovary and petal (PubMed:28167023). Expressed during ovary development with the highest expression on the third day after the flower fully opened (PubMed:21735233). During seed germination, expressed in the cotyledon. Expressed strongly in the pollen grain. Expressed in the developing fruits, in which mainly expressed in the vascular tissues and seeds. During growth, strongly expressed in leaf, where mainly expressed in the trichome and in the root tip and lateral root formation sites. Expressed in the vascular tissue and the epicycle of the root. Also expressed in branch (PubMed:27645097). By tomato fruit ripening. Expression in tomato fruits is up-regulated by exogenous application of ethylene and down-regulated by inhibition of ethylene receptors with 1-methylcyclopropene (1-MCP) (PubMed:26959229, PubMed:26716451). Up-regulated by plant hormone abscisic acid (ABA) in tomato fruits (PubMed:26959229). Expression is not up-regulated by plant hormone auxin in tomato fruits (PubMed:26716451). Up-regulated by auxin and gibberellic acid (GA), and down-regulated by ethylene in seedlings (PubMed:28167023). Down-regulated during decapitation-induced axillary shoot development and by excision of immature leaves. Down-regulation is inhibited by the application of auxin on the cut surface (PubMed:27645097). Simultaneous RNAi-mediated silencing of both ARF2A and ARF2B results in severe defects in tomato fruit ripening process (PubMed:26959229, PubMed:26716451). Plants form triple cotyledons and have enhanced root branching. Tomatoes have reduced pigment accumulation, enhanced fruit firmness, low climacteric ethylene production and inability to ripen upon exogenous application of ethylene (PubMed:26716451). The fruits are either parthenocarpic or contain only a few seeds, and the time from anthesis to breaker (Br) developmental stage is significantly extended compared to wild type fruit (PubMed:26959229). Altered expression of ethylene biosynthesis, signaling and ethylene response factor (ERF) genes and genes involved in the carotenoid pathway and ripening-related cell wall metabolism. Up-regulates auxin-responsive genes (PubMed:26716451). Down-regulated expression levels of ripening regulators, including RIN, AP2a, NOR, TAGL1, ETR3, ERF1 and CNR at the red (R) fruit stage. Expression levels of hormones such as abscisates, cytokinins and salicyclic acid are altered, and levels of carotenoids phytoene, phytofluene and lycopene are reduced in red fruits. Gibberellic acid (GA) and auxin expression levels are unchanged. Compounds normally reduced upon ripening show higher levels than wild type fruit as a result of simultaneous silencing of ARF2A and ARF2B (PubMed:26959229). RNAi-mediated silencing of ARF2A results in increased frequency of polycotyledons and significantly increased lateral organ development. Lateral shoot emergence occurs at the first leaf node compared to eighth leaf node in wild type. An unusual meristem appears in the mature leaf and lateral shoot development appears below the position of the cotyledon nodes. Unusual lateral branches also appear in the stem, which is located far from the leaf node. Epiderm is split along the axis at the site of the unusual meristem. Abnormally enlarged interfascicular cambia and phloem. Altered auxin distribution, and expression of auxin transporter PIN genes and ectopic axillary shoot-related transcriptional factors (PubMed:27645097). Belongs to the ARF family.