Table 1.
Effects of nitrate (NO3−) and ammonium (NH4+) availability on plant pathogen resistance
| Type | Nutrition strategy | Positive effect of NO3− on plant resistance | Negative effect of NO3− on plant resistance | Positive effect of NH4+ on plant resistance | Negative effect of NH4+ on plant resistance |
|---|---|---|---|---|---|
| Bacteria | Biotroph | 1 | 3 | 1 | 0 |
| Fungi | Biotroph | 1 | 4 | 2 | 1 |
| Nematode/Protist | Biotroph | 1 | 3 | 3 | 1 |
| Virus | Biotroph | 0 | 1 | 4 | 1 |
| Oomycota | Biotroph | 1 | 0 | 0 | 1 |
| Bacteria | Hemibiotroph | 1 | 2 | 2 | 1 |
| Fungi | Hemibiotroph | 5 | 3 | 3 | 5 |
| Oomycota | Hemibiotroph | 1 | 1 | 1 | 1 |
| Bacteria | Necrotroph | 0 | 2 | 0 | 0 |
| Fungi | Necrotroph | 9 | 4 | 4 | 7 |
| Total | Biotroph | 4 | 11 | 10 | 4 |
| Hemibiotroph | 7 | 6 | 6 | 7 | |
| Necrotroph | 9 | 6 | 4 | 7 |
Results of a survey of different studies are summarized, comparing different pathogen types, separated by their nutrition strategy. The impact of different inorganic N sources on the plant’s immune response during respective pathogen attacks were denoted. Effects are expressed through increased resistance and elevated susceptibility, respectively. Respective numbers express the count of experiments found, displaying a similar response. A summary of the counts is presented in bold, with no differentiation between different pathogen types, but grouped according to nutrition strategy. Respective references to the included studies can be found in Supplementary Tables 1–3