>>2607637>>2607637plants need sunlight as a calorie source, they need minerals and organic material from the soil as a micronutrient source. they cannot take certain nutrients directly from the soil, so they have to "trade" nutrients with microorganisms which are in a symbiotic relationship with them. similar to the animal digestive system, if the microbiome is unhealthy or not present, the organism cannot utilize its food properly, leading to nutrient deficiencies, leading to disease or simply malnutrition/malnourisment.