cis-regulatory-variation
Cis-regulatory variation refers to differences in DNA sequences that control when, where, and how much a gene is expressed, acting through nearby regulatory elements such as promoters and enhancers. In plant science, these variations are a major driver of trait diversity, influencing everything from stress tolerance and flowering time to yield and developmental architecture. Understanding cis-regulatory variation helps researchers identify the molecular basis of adaptive traits and accelerates breeding programs aimed at improving crop performance.
open_in_new WikipediaPubMed · 2026-04-29
Scientists identified a natural genetic variant in maize that controls how well corn plants survive drought during flowering — the make-or-break window for grain production. A tiny DNA deletion in a gene's control switch keeps a drought-response gene active, shortening the gap between male and female flowering and preserving yield under water stress.
A 12-base-pair deletion in the ZmABI45 gene promoter prevents the repressor protein ZmbHLH80 from silencing it, enabling drought-stress responses to activate more readily.
Maize plants engineered to overexpress ZmABI45 showed significantly shorter anthesis-silking intervals and improved grain yield under drought conditions.
Evolutionary analysis confirmed the drought-tolerant deletion variant has been positively selected during modern maize breeding and is geographically concentrated in low-rainfall regions.
