Transcriptomics Combined with Physiology Reveals the Effect of Different Light Qualities on the Development of Fritillaria Cirrhosa In the Qinghai Tibet Plateau

Fritillaria cirrhosa, a high-altitude plant susceptible to environmental conditions, commonly grows beneath bushes and is characterized as a shade-tolerant plant. The development and secondary metabolite synthesis of F. cirrhosa are significantly influenced by light quality. This study investigated the physiological responses and molecular mechanisms of F. cirrhosa under different light quality using colored agricultural films treatments. The study revealed that F. cirrhosa under different agricultural films exhibited varying degrees of inverted seedlings, fruit quality, and seed fullness, with blue film (BF) having the highest levels, followed by green film (GF), yellow film (YF), and white film (WF) (P<0.01). The content of guanosine was the highest in BF, and uracil was the highest in GF. Interestingly, F. cirrhosa exhibited improved photosynthesis at BF and YF compared to WF and GF (P<0.05), based on analyses of photosynthesis and fluorescence data. The transcriptome results indicated that 75 differentially expressed genes (DEGs) involved in photosynthetic related pathways regulated photosynthetic utilization efficiency by encoding photosynthetic–antenna proteins (Lhca and Lhcb), photosynthetic electron transporters (PsbE, PsbP and PetA) and carbon fixation enzymes (PPC, PPDK and rbcL). The majority of these genes were upregulated in BF and GF, improving light energy conversion efficiency, photosynthetic electron transport rate, and CO2 assimilation ability in F. cirrhosa. Notably, 44 DEGs involved in flavonoid metabolic pathways (PAL, HCT, 4CL, CHS, CHI, and ANS) showed higher expression levels in WF and YF, differing from the regulation of the photosynthetic pathway. This suggests that F. cirrhosa can utilize nutrients produced by photosynthesis more efficiently under BF and GF, and do not require excessive amounts of flavonoids for cell homeostasis maintenance. The results offer valuable insights into the transcriptional changes and molecular processes occurring in F. cirrhosa in response to different light qualities, and provide a basis for research on the mechanisms of photoregulation cultivation and ecological adaptation in F. cirrhosa.