Table 1.
Arabidopsis genes described in this review
| I. Mechanosensitive ion channels | |||||
|---|---|---|---|---|---|
| Family | Gene name | Gene locus | Mutant phenotype | Subcellular localization | Single-channel characteristics |
| Mid-1 comple- menting activity | MCA1 | At4g35920 | mca1 mutants are less able to penetrate hard agar (Nakagawa et al., 2007), hyperproduce lignin; mca1 mca2 double mutants are hypersensitive to MgCl2 and show developmental delays (Yamanaka et al., 2010) | Plasma membrane (Nakagawa et al., 2007) | ~15 or ~35 pS conductance in Xenopus ooctyes (Furuichi et al., 2012) |
| MCA2 | At2g17780 | mca2 mutants show a reduction in Ca2+ uptake (Yamanaka et al., 2010); see MCA1 entry | Plasma membrane (Yamanaka et al., 2010) | NR | |
| MscS-like | MSL1 | At4g00290 | NR | NR | NR |
| MSL2 | At5g10490 | msl2 null mutants show defective leaf shape (Jensen and Haswell, 2012 ); msl2 msl3 double mutants have enlarged chloroplasts and enlarged, round non-green plastids (Haswell and Meyerowitz, 2006); msl2 msl3 double mutant chloroplasts exhibit multiple division rings (Wilson et al., 2011) | Plastid envelope (Haswell and Meyerowitz, 2006) | NR | |
| MSL3 | At1g58200 | (See MSL2 entry) | Plastid envelope (Haswell and Meyerowitz, 2006) | NR | |
| MSL4 | At1g53470 | msl4 msl5 msl6 msl9 msl10 quintuple lacks a predominant MS channel activity in root protoplasts (Haswell, Peyronnet et al., 2008) | NR | NR | |
| MSL5 | At3g14810 | (See MSL4 entry) | NR | NR | |
| MSL6 | At1g78610 | (See MSL4 entry) | NR | NR | |
| MSL7 | At2g17000 | NR | NR | NR | |
| MSL8 | At2g17010 | NR | NR | NR | |
| MSL9 | At5g19520 | (See MSL4 entry) | Plasma membrane (Haswell, Peyronnet et al., 2008) | ~45 pS in root protoplasts (Haswell, Peyronnet et al., 2008) | |
| MSL10 | At5g12080 | (See MSL4 entry) | Plasma membrane (Haswell, Peyronnet et al., 2008) | ~137 pS conductance in root protoplasts (Haswell, Peyronnet et al., 2008); ~100 pS conductance in Xenopus oocytes and a moderate preference for anions (Maksaev and Haswell, 2012) | |
| Piezo | At2g48060 | NR | NR | NR | |
| II. Candidate RLK mechanosensors | |||||
| Family | Gene name | Gene locus | Mutant phenotype | Subcellular localization | Ligands |
| Wall-associated kinases | WAK2 | At1g21270 | wak2 mutants show reduced cell expansion under sugar limited conditions (Kohorn et al., 2006), loss of pectin-induced MAPK3 activation, and loss of pectin-induced differential gene expression (Kohorn et al., 2009). 35S-driven antisense expression targeting all WAKS apparently lethal (Wagner and Kohorn, 2001) | Plasma membrane (Kohorn and Kohorn, 2012) | Pectin (de-esterified, charged galacturonic acid backbone; Kohorn et al., 2009) |
| II. Candidate RLK mechanosensors | |||||
| Family | Gene name | Gene locus | Mutant phenotype | Subcellular localization | Ligands |
| CrRLK1L | THE1 | At5g54380 | the1 single mutants have no obvious growth phenotype; the1 partially rescues prc1-1 growth defects and ectopic lignification in the1 prc1-1 double mutant (Hematy et al., 2007) and shows reduced reactive oxygen species production and lignification in response to isoxaben treatment (Denness et al., 2011); the1 herk1 herk2 triple mutants have shortened petioles and hypocotyls (Guo et al., 2009a , b ) | Plasma membrane (Hematy et al., 2007) | NR |
| HERK1 | At3g46290 | the1 herk1 double mutants have shortened petioles, the1 herk1 herk2 triple mutants also have shortened hypocotyls (Guo et al., 2009a , b ) | Probably plasma membrane (Guo et al., 2009b ) | NR | |
| HERK2 | At1g30570 | the1 herk1 herk2 triple mutants have shortened hypocotyls (Guo et al., 2009a , b ) | NR | NR | |
| FER | At3g51550 | fer null mutant have reduced leaf expansion, shorter inflorescences (Guo et al., 2009b ), and bursting/ bulging root hairs (Duan et al., 2010) | Plasma membrane (Duan et al., 2010) | NR | |
| ANX1 | At3g04690 | anx1 anx2 double mutants show bursting pollen tubes and failure to reach female gametophyte (Boisson-Dernier et al., 2009) | Preferential localization to plasma membrane of pollen tube tip (Boisson-Dernier et al., 2009) | NR | |
| ANX2 | At5g28680 | (See ANX1 entry) | (See ANX1 entry) | NR | |
| NR, not reported. | |||||