SQUAMOSArelated

SQUAMOSA-related genes are a group of transcription factors that play a crucial role in plant development, particularly in the regulation of floral organ identity. These genes belong to the MADS-box family, a large class of transcription factors characterized by a conserved DNA-binding domain called the MADS-box. The term "SQUAMOSA-related" (or SR) refers to genes that share homology with the *SQUAMOSA* gene in *Arabidopsis thaliana*, which is essential for the transition from vegetative to reproductive growth in this model organism.

The SR gene family is widely distributed across flowering plants (angiosperms) and includes genes such as *APETALA1* (AP1) and *CAULIFLOWER* (CAL) in *Arabidopsis*, as well as *LEAFY* (LFY) and its homologs in other species. These genes function in the floral meristem identity pathway, ensuring proper formation of floral organs by specifying the switch from vegetative growth to flowering. They also influence other developmental processes, including leaf and inflorescence architecture, as well as responses to environmental cues like photoperiod and temperature.

In many plants, SR genes are expressed in meristematic tissues and are regulated by upstream factors such as *LEAFY* and *FLOWERING LOCUS T* (FT). Mutations or disruptions in SR genes often result in abnormal floral development, such as the formation of vegetative-like structures in place of flowers or altered organ identity. For example, mutations in *AP1* in *Arabidopsis* lead to the production of cauliflower-like inflorescences instead of discrete flowers.

The study of SR genes has significant implications for plant breeding and agriculture, as they influence traits like flowering time, plant architecture, and reproductive success. Understanding their regulatory networks helps researchers develop crops with improved yield, stress tolerance, and adaptability to changing environments. Additionally, SR genes are valuable tools in synthetic biology for engineering novel plant forms and functions.