Table 3.
Main functions of micronutrients in plants
| Element | Symbol | Main physiological functions in plants | References |
|---|---|---|---|
| Boron | B | Cell wall synthesis and structure, cell membrane function, lignification, IAA formation, nodule development, other (secondary) processes | 1, 2, 3, 4 |
| Cobalt | Co | Nodule initiation | 3 |
| Copper | Cu | Essential for photosynthesis, mitochondrial respiration, C and N metabolism, oxidative stress protection, catalytic metal in many oxidases, pollen fertility, plant defense, synthesis of phenolics, photosynthesis | 1, 2, 4, 5 |
| Iron | Fe | Central part of hemoproteins (e.g., cytochromes), involved in photosynthesis, mitochondrial respiration, N assimilation, hormone biosynthesis, osmoprotection, pathogen defense, oxidative stress protection | 1, 2, 4, 6, 7 |
| Manganese | Mn | Cofactor/activating role for at least 36 enzymes, protection from free radicals, involved in shikimic acid pathway and production of phenolics, fatty acid synthesis, N metabolism, C fixation, chloroplast function | 1, 2, 4, 6, 7 |
| Molybdenum | Mo | N assimilation and fixation (e.g., nitrogenase, nitroreductase), biosynthesis of abscisic acid | 1, 2, 4 |
| Nickel | Ni | Urease activity, hydrogenase activity in legume nodules | 2, 4 |
| Zinc | Zn | Component of many proteins involved in DNA replication, transcription, translation, C fixation, carbohydrate and protein metabolism, oxidative stress protection, disease resistance | 1, 2, 4, 6, 7 |