Table 2. Survey of differential screening experiments in nodulation research.
| Host plant |
Technique |
Sourcea |
Screenedb |
Candidatesc |
Processedd |
Confirmede |
Newf |
Ref |
| Pea | DH | –; wt 14 d | 600 | – | 6 | 6 | 6 | 91 |
| Soybean | DH | –; wt 10 d | – | 10 | 10 | 3 | >1 | 92 |
| Pea | DH | –; wt 2 d | 3000 | – | – | 3 | 3 | 106 |
| Soybean | SH | –; wt 21 d | 150 000 | 1200 | – | 20 | 9 | 93 |
| –; wt 8 d | 100 000 | 250 | ||||||
| Broad bean | SH | –; wt 30 d | 55 000 | 700 | 700 | 27 | 19 | 104 |
| Alfalfa | DH | –; spontaneous nod. | – | – | – | – | 1 | 107 |
| Pea | SH | –; wt 35 d | 60 000 | 500 | 500 | 19 | – | 108 |
| M.truncatula | SH | –; wt 48, 108 h | – | – | – | – | 1 | 109 |
| S.rostrata | DD | –; wt 2, 3, 4 d | 2800 | 45 | 17 | 5 | 5 | 82 |
| M.truncatula | SH | nodA–; wt 4 d | 30 000 | 473 | 473 | 30 | 29 | 110 |
| Vetch | DD | –; NF 1, 3 h | 27 600 | 34 | 9 | 1 | 1 | 100 |
| L.japonicus | DD | –; wt 7, 11, 13, 21 d | 8000 | 137 | 137 | 19 | 13 | 101 |
| M.truncatula | ESTS | root hair-enriched root | 985 | 899 | – | – | – | 97 |
| M.truncatula | DD | –; NF 2 h | 4000 | 0 | – | – | – | 111 |
| –; NF 24 h | 2400 | 0 | – | – | – | 111 | ||
| –; NF 48 h | 2000 | 4 | 4 | 2 | >1 | 111 | ||
| Alfalfa | CPS | –; spontaneous nod. | 250 | 21 | 21 | 14 | 14 | 95 |
| M.truncatula | ESTS | wt 4–8 d | 408 | 389 | 389 | 117 | 84 | 98 |
| Alfalfa | CPS | Nod–; wt 5 d | 1000 | 38 | 38 | 38 | 22 | 96 |
| Yellow lupine | DD | –; wt 21 d | 3500 | 50 | 14 | 4 | 4 | 112 |
| S.rostrata | DD | –; wt 1, 2, 4, 8, 12, 48 h | 4000 | 57 | 34 | 9 | 6 | this work |
DH, differential hybridization; SH, subtractive hybridization; DD, differential display; ESTS, EST sequencing; CPS, cold-plaque screening.
aSamples compared in the experiment: –, uninoculated; wt, wild-type microsymbiont; nodA– and Nod–, mutant microsymbiont strains; NF, pure Nod factors. For details, see original articles.
bNumber of clones screened as plaques or colonies in the case of differential or subtractive hybridization and cold-plaque screening, bands displayed on gel for differential display, or corresponding to the number of clones sequenced in the case of EST sequencing. For the reports on differential display experiments in which no average amount of bands displayed per gel was cited, 100 was taken as the amount to calculate the approximate number of bands visualized.
cNumber of candidates, putatively differentially expressed, obtained in the differential screening experiment, or the number of readable sequences from EST sequencing.
dNumber of candidates that were further processed to confirm their differential expression pattern.
eNumber of unique clones for which the differential expression pattern could be confirmed.
fNumber of novel genes among the confirmed clones.