SPL7

SPL7, or SQUAMOSA PROMoter-BINDING PROTEIN-LIKE 7, is a gene encoding a transcription factor in plants. It is a member of the SPL (SQUAMOSA PROMOTER-BINDING PROTEIN-LIKE) family, which is defined by the SBP-box DNA-binding domain that recognizes GTAC core sequences in target promoters.

In the model plant Arabidopsis thaliana, SPL7 serves as a central regulator of copper homeostasis, especially under conditions of copper deficiency. It activates transcription of genes involved in copper uptake and transport, enabling plants to acquire copper from the soil and to reroute intracellular copper where it is needed.

The protein's activity is tied to copper status and contributes to the plant's transcriptional response to micronutrient limitations. Through its regulatory network, SPL7 coordinates the expression of copper transporters and copper-containing enzymes to maintain essential metabolic processes.

Genetic studies in Arabidopsis have shown that loss of SPL7 results in impaired copper uptake and growth defects under copper-limited conditions, while altering SPL7 activity can influence copper homeostasis.

SPL7 is one of several SPL family transcription factors that regulate diverse developmental and physiological processes in plants. While the broader SPL family is frequently discussed in the context of development and microRNA regulation, SPL7 is specifically recognized for its role in micronutrient regulation and copper homeostasis.