Table 1.
Expression, functions, peptide ligands, UniProt IDs, and Protein Data Bank(PDB) IDs of the major known receptor kinases (LRR-RKs) in Arabidopsis thaliana.
| LRR Name | Peptide Ligands | Expression | Function | UniProt ID | PDB ID |
|---|---|---|---|---|---|
| ERECT | EPF1/2 EPFL4/5/6 |
Shoot Apical Meristem (SAM), Xylem, Phloem, Epidermis [20,21] | Stomatal patterning, regulates inflorescence [22,23,24,25] | Q42371 | X |
| ERL1 | EPF1/2 | Developing organ, bud clusters, flowers, SAM, leaf primordia [26] | Stomatal patterning, inflorescence, organ shape [25,26,27] | C0LGW6 | X |
| ERL2 | Developing organ, bud clusters, flowers, SAM, leaf primordia [26] | Stomatal patterning, inflorescence, organ shape [25,26] | Q6XAT2 | X | |
| PEPR1 | PEP1 | Leaf, flower, root [28,29] | Pathogen-associated Molecular Pattern (PAMP)-triggered immune signaling [30,31] | Q9SSL9 | 5GR8 |
| PEPR2 | Leaf, flower, root | Immune signaling similar to PEPR1 | Q9FZ59 | X | |
| PSKR1 | PSK | Root primordia, leaves, stems and flowers [32,33,34] | Plant cell differentiation, somatic embryogenesis, cellular proliferation, plant growth [35,36] | Q9ZVR7 | 4Z63/4Z64 |
| PSYR1 | PSY1 | SAM and elongation zone of root meristem [37] | Cellular proliferation and plant growth, not involved in Phytosulfokine (PSK) sensing [35,36,37]. | Q9C7S5 | X |
| EFR | Leaf protoplast, petal, stigma [38] | Involved in plant defense [39,40] | C0LGT6 | X | |
| PXC2 | Cotyledons, shoot apex, hypocotyls [41] | Vascular development [41] | Q9LZV7 | X | |
| CLV1 | CLV3 CLE2 |
SAM and early flower meristem [42,43] | Meristem maintenance [42,43] | Q9SYQ8 | X |
| TDR | TDIF | Vascular meristem [44] | Regulation of procambium maintenance [44,45,46] | Q9FII5 | 5JFK/5GIJ 5GQR |
| MIK1 | LURE1.2 (?) | Pollen tubes [46] | Pollen tube guidance, vascular tissue development [46] | Q9M0G7 | X |
| BAME1 | CLV3 CLE5/11/18/19/22/26/40/41/42 |
Roots, leaves, flowers, anther, and gynoecium [47,48] | Gametophyte development, anther development, vascular strand development within leaves [47,48,49] | O49545 | X |
| BAME2 | CLV3 CLE11/18/19/22/25/40/41/42 |
Seedlings, roots, flowers, cortex of developing stems, anther, and gynoecium [47] | Male gametophyte development, ovule development, vascular strand development within leaves [47,48] | Q9M2Z1 | X |
| FLS2 | flg22 | Ubiquitously expressed [15] | Flagellin perception, innate immune response [15,50] | Q9FL28 | 4MNA/4MN8 |
| PRK3 | Pollen and flowers [51] | Pollen tube growth, pollen germination [52] | Q9M1L7 | 5WLS | |
| PRK6 | AtLURE1.2 | Tip of the pollen tube [53] | Pollen tube guidance, LURE perception [53,54] | Q3E991 | 5Y9W/5YAH |
| BAK1 | Ubiquitously expressed [55] | Brassinosteroid signaling, PAMP mediated immune response, interacts with FLS2, Elongation Factor tu receptor (EFR). Involved in Phosphorylation of BRI1. | Q94F62 | 3ULZ | |
| SERK1 | Vascular bundles, flowers, and embryo sac [56,57] | Phosphorylation of BRI1, brassinolide signaling pathway [58] | Q94AG2 | 4LSC | |
| SERK2 | Developing vascular tissues, flowers, embryo sac [58] | Brassinosteroid dependent and independent pathways, male gametophytic production [58] | Q9XIC7 | 5GQR/4Z61 | |
| SBIR1 | Mostly in leaves and flowers [59] | Activation of plant defense and cell death [60] | Q9SKB2 | X | |
| PXL1 | Mostly in root | Procambium maintenance during vascular tissue maintenance | Q9FRS6 | X | |
| EMS1 | Young buds, flowers, organ primordia, young pollen grains [61] | Embryonic development. In seeds plays a role in cell size enhancement | Q9LYN8 | X | |
| FEI1 | Root meristem and elongation zone | Regulates cell wall function, cellulose biosynthesis [62] | C0LGF4 | X | |
| GSO1 | CIFs | Seeds, developing embryos, flower buds, and roots [63,64] | Embryo and cotyledons epidermal surface development regulate root growth [63,65] | C0LGQ5 | X |
X denotes no structure is available in the PDB. (?) denotes debatable.