Table 5.
Changes in the endogenous content of major polyamines (PAs), stress-associated amino acids, and stress-associated phytohormones in citrus and its relative species as affected by water stress.
| ‘Cultivar’/Variety/(species) | Tissue | Treatment/experimental design | Pro a | Arg | JA | ABA | Put | Spd | Spm | Reference |
|---|---|---|---|---|---|---|---|---|---|---|
| ‘Red Tangerine’ (C. reticulata) | Leaves | The role of spermine application (1 mM) in dehydration tolerance after 12 hpt in vitro. | - | - | - | - | ▲ | ▲ | ▲ | 57 |
| Tomato (Solanum lycopersicum ‘Zhongshu No. 4′) | Leaves | Overexpression of PtADC gene from P. trifoliata in transgenic tomato plants | - | - | - | - | ▲ | ▲ | ↑↓ | 82 |
| Tobacco (Nicotiana nudicaulis) overexpressing PtADC | Leaves | Overexpression of PtADC gene from P. trifoliata in transgenic tobacco plants | - | - | - | - | ▲ | ▲ | ● | 82 |
| Citrumelo CPB 4475 (C. paradisi × P. trifoliata) | Roots | Severe drought stress by transplanting plants to dry perlite for different periods | - | - | ▲ | ▲ | - | - | - | 184 |
| ‘Owari’ Satsuma orange (C. unshiu) | Leaves | Dropping the soil moisture content to 20% of the water holding capacity for 5 days | ▲ | ▼ | - | - | ● | ● | ▼ | 4 |
| Tobacco (N. nudicaulis) overexpressing FcWRKY70 | Leaves | Overexpression of FcWRKY70 from ‘Meiwa’ Kumquat (Fortunella crassifolia) | - | - | - | - | ▲ | - | - | 185 |
| Cleopatra mandarin (C. reticulata), | Leaves | Progressive drought was imposed by transplanting plants to perlite, ceasing watering and allowing the substrate to dry for a period of 14 days. | ▲ | - | ▲ | ▲ | - | - | - | 186 |
| Carrizo citrange (C. sinensis × P. trifoliata) | Leaves | Progressive drought was imposed by transplanting plants to perlite, ceasing watering and allowing the substrate to dry for a period of 14 days. | ▲ | - | ▲ | ▲ | - | - | - | 186 |
| ‘Jincheng’ Sweet orange (C. sinensis) | Leaves | The seedlings were dehydrated in vitro at 25°C | - | - | - | - | ▲ | ▲ | ▼ | 11 |
| Rangpur Lime (C. limonia) b | Leaves & Roots | Either ungrafted or grafted subjected to distinct watering regimes (well-watered vs. severe drought) | - | - | - | ▲ | - | - | - | 180 |
| ‘Sunki Maravilha’ mandarin (C. sunki) b | Leaves & Roots | Either ungrafted or grafted subjected to distinct watering regimes (well-watered vs. severe drought) | - | - | - | ▲ | - | - | - | 180 |
| ‘Valencia’ Sweet Orange (C. sinensis) on C. limonia | Leaves & Roots | Responses of Valencia scion grafted on two rootstocks, Rangpur Lime (C. limonia) and ‘Sunki Maravilha’ mandarin (C. sunki), during three successive periods of water deficit | - | - | - | ▲ | - | - | - | 187 |
| ‘Havana’ Tobacco (N. tabacum) overexpressing CsNCED3 | Leaves | Overexpression of CsNCED3 from ‘Rangpur’ lime (C. limonia) | - | - | - | ▲ | - | - | - | 188 |
a(▲) signifies for increased levels, (▼) signifies for decreased levels, (●) signifies for no significant change, (↑↓) signifies for varied responses, and (˗) signifies for not-reported compounds. Abbreviations: Pro: L-proline, Arg:L-Arginine, JA: jasmonic acid, ABA: abscisic acid, Put: putrescine, Spd: spermidine, and Spm: spermine.
bThe two Citrus rootstocks (Rangpur lime and ‘Sunki Maravilha’ mandarin) either ungrafted or grafted with their reciprocal graft combinations or with shoot scions of ‘Valencia’ Sweet Orange (C. sinensis) and Tahiti acid lime (C. latifolia) subjected to distinct watering regimes (well-watered vs. severe drought)