zma-miR399b-5p: Zma-mir399b-5p is a member of the miR399 family of microRNAs [PMC6214007]. Decreased expression of several miRNAs, including zma-mir399b-5p, leads to an increase in the expression of genes involved in the fatty acid biosynthetic process, promoting fatty acid metabolism and lipid delivery from plants to arbuscular mycorrhizal (AM) fungi [PMC9499406]. In a study, zma-mir399b-5p was found to be down-regulated [PMC6214007]. Along with zma-miR399h-5p and zma-miR397b-5p, zma-mir399b-5p is believed to control the expression of genes involved in fatty acid metabolism and/or transportation [PMC6214007]. Specifically, Zm00001d003797, a root r-b1-like gene, was found to be regulated by zma-miR399d-5p, zma-mir399b-5p, and zma-miR399h-5p [PMC6214007]. In another study, three different differentially expressed long non-coding RNAs (DELs) were found to adsorb miRNAs including zma-mir399b-5p [PMC8756644]. These findings suggest that zma-mir399b-5p plays a role in regulating genes involved in fatty acid metabolism and transportation.