Timeline of Key Discoveries Relevant to PP-04
Key Firsts:
| Discovery | Scientist(s) | Year | Significance |
|---|---|---|---|
| Cohesion-tension theory | Dixon & Joly | 1894 | Primary water ascent mechanism |
| Legume fixation by bacteria | Hellriegel & Wilfarth | 1888 | Symbiotic nitrogen fixation |
| Essentiality criteria | Arnon & Stout | 1939 | Defined "essential element" |
| Nitrogenase characterisation | Carnahan et al. | 1960 | First in vitro nitrogen fixation |
| 17th essential element (Ni) | Brown et al. | 1987 | Urease requires Ni |
| Aquaporins in plants | Maurel et al. | 1993 | Facilitated water transport |