The main transportation pathway for nutrients in plants is through the phloem, a type of vascular tissue. Phloem transports photosynthates (sugars produced during photosynthesis) from leaves to non-photosynthetic parts, such as roots and stems, where they are used for energy or storage. This bidirectional flow ensures that all parts of the plant receive the necessary nutrients for growth, maintenance, and reproduction. Effective nutrient transport is critical for plant health and overall ecosystem productivity.