Table 1.
Transcription factor functions in spikelet initiation and development
| Family | Gene function | Arabidopsis | Rice | Maize | Barley | Wheat | Sorghum |
|---|---|---|---|---|---|---|---|
| MADS | IM, SMs and FMs identity | APETALA1 (AP1) (Wigge et al. 2005), CAULIFLOWER (CAL) and FRUITFULL (FUL) (Ferrandiz et al. 2000) | OsMADS14, OsMADA15 and OsMADS18 (Wu et al. 2017) | – | – | VRN1, FUL1 and FUL3 (Li et al. 2019) | – |
| OsMADS1, OsMADA5 and OsMADS34 (Wu et al. 2018) | – | – | – | – | |||
| bHLH | AM activity | REGULATOR OF AXILLARY MERISTEM FORMATION (ROX) (Yang et al. 2012) | LAX PANICLE1 (LAX1) (Tabuchi et al. 2011) | Barren stalk1 (ba1) (Gallavotti et al. 2004) | – | – | – |
| – | LAX2 (Tabuchi et al. 2011) | BA2 (Yao et al. 2019) | – | – | – | ||
| SPL | AM activity | SQUAMOSA PROMOTER BINDING PROTEIN-LIKE 3 (SPL3), SPL9 and SPL15 (Wang et al. 2009; Yamaguchi et al. 2009) | OsSPL14 (Jiao et al. 2010; Miura et al. 2010; Wang et al. 2017; Zhang et al. 2017b) | – | – | TaSPL3, TaSPL17 (Liu et al. 2017) | – |
| euAP2 | Spikelet number | – | – | – | HvAP2 (Houston et al. 2013) | Q (Zhang et al. 2011) | – |
| AP2-ERF | AM activity and SpM identity | – | FRIZZY PANICLE (FZP), MULTI-FLORET SPIKELET1 (MFS1) (Bai et al. 2017; Ren et al. 2013) | Branched silkless1 (bd1) (Chuck et al. 2002) | Compositum 2 (com2) (Poursarebani et al. 2015) | Branched headt-A1 (bht-A1) (Poursarebani et al. 2015) | – |
| TCP | AM activity and boundary formation | – | OsTB1 (Lyu et al. 2020) | TEOSINTE BRANCH1 (TB1) (Doebley et al. 1997) | HvTB1/INTERMEDIUM-C (INT-C) (Ramsay et al. 2011) | TaTB1 (Dixon et al. 2018b) | MULTISEEDED 1 (MSD1) (Jiao et al. 2018) |
| – | OsTB2/RETARDED PALEA1 (REP1) (Lyu et al. 2020) | Branch angle defective1 (bad1)/Wavy auricle in blade1 (Wab1) (Lewis et al. 2014) | COMPOSITUM 1 (COM1) (Poursarebani et al. 2020) | – | SbWab1 (Poursarebani et al. 2020) |