[3] The phloem and xylem of plants are rich in carbohydrates (in the form of sucrose) but lack lipids and proteins.
Lipids can be synthesized from carbohydrates; however, proteins require nitrogen, which is not commonly found in plant sap.
[1] Leafhoppers return the favor by providing shelter in the form of a specialized organ in their abdominal cavity called a bacteriome, which they have on both sides of their abdomens.
[5] These bacteriocytes comprise an organ called a bacteriome, whose cells host a variety of bacterial endosymbionts.
As a result, their genomes often lack genes that would be required for life in an extracellular environment, even one containing abundant nutrients.