<![CDATA[Flavone synthase (FNS) is a key enzyme involved in the conversion of flavanones into flavones, a class of secondary metabolites that contribute to plant defense through their antimicrobial and antioxidant properties. These bioactive compounds play an important role in mitigating oxidative stress induced by environmental factors, including ultraviolet (UV) radiation and other stressors relevant to Chemical, Biological, Radiological, Nuclear, and Explosives (CBRNE) scenarios. Bidens pilosa L. is a herbaceous plant recognized for its rich flavonoid content, particularly in its leaves and stems, making it a promising source of bioactive phytochemicals. This study aimed to evaluate tissue-specific FNS gene expression in B. pilosa to assess its flavonoid biosynthetic potential and its prospective relevance to CBRNE protective phytotechnology. Total RNA was isolated from fresh leaf and stem tissues using the phenol–chloroform method, followed by cDNA synthesis through reverse transcription. Gene expression analysis was conducted using real-time quantitative PCR (RT-qPCR), with FNS as the target gene and actin as the reference gene. The results revealed differential FNS expression between leaf and stem tissues, indicating variations in flavonoid biosynthesis and potential flavonoid accumulation. These findings provide a molecular basis for evaluating flavonoid-producing capacity in B. pilosa and support the exploration of plant-derived antioxidant resources for future applications in protective phytotechnology and resilience against oxidative stress associated with CBRNE-related environmental challenges.]]>
