zma-mir399b-5p: Zma-mir399b-5p is a microRNA (miRNA) in maize that plays a crucial role in the regulation of fatty acid metabolism and transportation [PMC6214007]. This miRNA is one of the differentially expressed miRNAs (DEMs) that, when decreased in expression, leads to the upregulation of genes involved in fatty acid biosynthesis, thereby enhancing lipid transfer to arbuscular mycorrhizal (AM) fungi [PMC9499406]. Zma-mir399b-5p is part of the larger miR399 family, but it is not accurate to state that all twelve members are implicated in the regulation of fatty acid metabolic processes without specific evidence for each [PMC6214007]. The downregulation of zma-mir399b-5p has been observed in maize studies, which indicates its potential regulatory function [PMC6214007]. Furthermore, zma-mir399b-5p targets and controls the expression of genes such as Zm00001d003797, a root r-b1-like gene [PMC6214007]. Additionally, this miRNA interacts with long non-coding RNAs (lncRNAs) like MSTRG.15598.1 and MSTRG.15598.3, which are involved in gene regulation mechanisms within the plant [PMC8756644].