Isolation of petal abscission zones (AZs) for molecular and biochemical studies is challenging due to their small size and the difficulty in separating them cleanly from surrounding non-AZ tissues, followed by the rapid exposure of the excised tissue to wound and dehydration stresses, post-excision. Immediate freezing of all the excised tissue is essential but practically difficult. In this chapter, we present a refined protocol for isolating petal AZ tissues from rose petals by optimizing the dissection process to minimize contamination with non-AZ cells coupled with immediate freezing to prevent stress-induced artifacts. The protocol includes careful tissue handling, precise excision, and rapid freezing, enabling the acquisition of high-quality samples for subsequent molecular and biochemical analyses. We also provide a method that facilitates the study of promoters by GUS expression through agro-injection of rose flower buds.