HMG1 — Lactuca sativa

Summary

LsHMG1, also known as HMG1, encodes a hydroxymethylglutaryl-CoA reductase (HMGR) with NADPH activity, a key enzyme in the mevalonate (MVA) pathway. This gene is associated with the biosynthesis of sterols, triterpenoids, saponins, and other isoprenoids, as well as with phenylpropanoid metabolism and responses to jasmonic acid and the absence of light. The encoded protein localizes to multiple membranes, including the endoplasmic reticulum, plastid, and peroxisome membranes. LsHMG1 is linked to photosynthetic rate, plant height, biomass, flowering time, male fertility, and defense responses. Studies of related genes in other species connect the HMGR family to isoprenoid biosynthesis, phytosterol content, disease resistance, and fruit development, though these associations are not yet established in lettuce.