Plant gene expression is the fundamental biological process by which the genetic information encoded in plant DNA is transcribed into RNA and, subsequently, translated into proteins or utilized as functional RNA molecules, thereby determining cellular structure and function. As a core concept and research field, it investigates the intricate molecular mechanisms, regulatory networks, and dynamic patterns governing which genes are active, when, where, and how their products accumulate across plant tissues, developmental stages, and in response to environmental stimuli, providing critical insights into plant growth, development, metabolism, and adaptation.