Table 2.
Beneficial action of melatonin in plants infected with bacterial pathogens.
| Plant | Pathogen | Melatonin Dosage (µM) | Delivery Method | Mechanism | Effect | Ref. |
|---|---|---|---|---|---|---|
|
Arabidopsis thaliana, Nicotiana benthamiana |
Pseudomonas syringae | 1 or 10 | Leaf treatment | ▲ Expression of defense genes PR1, PR5, and PDF1.2 | Inhibition of pathogen propagation | [44] |
| A. thaliana | P. syringae | 10 | Leaf treatment | ▲ Pathogenesis-related (PR) genes by the harmonizing signaling between SA and ET |
Increase resistance against pathogen | [39] |
|
A. thaliana, N. benthamiana |
P. syringae | 1 | Leaf treatment | ▲ Induction of PR genes through MAPK signaling cascades | Disease resistance | [47] |
| A. thaliana | P. syringae | 20 | Added to nutrient solution | Involvement of sugars and glycerol in melatonin-mediated innate immunity in SA- and NO-dependent pathways |
Disease resistance | [42] |
| A. thaliana | P. syringae | 20 | Added to nutrient solution | ▲ NO and melatonin levels in leaves ▲ Defense-related genes |
Improvement of disease resistance | [43] |
| A. thaliana | P. syringae | 50 | Added to plant culture medium | ▲ Activities of CWI and vacuolar invertase (VI) |
Cell-wall reinforcement and callose deposition during infection | [45] |
| A. thaliana | P. syringae | 1 | Leaf treatment | Induction of PR1 and ICS1 expression genes through MAPK cascades in coexistence H2O2 and NO | Disease resistance | [48] |
▲ = increasing in content or action; SA = salicylic acid; PR1 and PR5 = plant resistance genes 1 and 5; ET = ethylene; MAPK = mitogen-activated protein kinase; NO = nitric oxide; PDF1.2 = plant defensin 1.2 gene; ICS1 = isochorismate synthase 1 gene; H2O2 = hydrogen peroxide.