Short-term low PPFD differentially affects protein profiles and terpenoid metabolism, and LED spectra drive clone-specific responses in Artemisia annua: implications for PFAL-based genotypic selection

Light is a key abiotic factor regulating plant-environment interactions; its short-term effects on terpenoid biosynthesis in Artemisia annua remain unclear under controlled environments. This study investigated how short-term variations in light intensity and spectrum are associated with terpenoid profiles and artemisinin-related compounds, aiming to elucidate the light-responsive pathway and assess genotype-dependent responses for PFAL. Transplants were exposed to low PPFD (60, 80, 120 μmol·m−2·s−1) for 7 days, while five genotypes were treated with white, blue, and red LEDs for 48 hours. Low PPFD maintained biomass and pigment stability, while 80 PPFD was associated with differences in light-responsive proteins and terpenoid biosynthetic proteins, accompanied by differences in terpenoid profiles. Light intensity was associated with variation among terpenoid classes, whereas spectral quality was associated with genotype-dependent responses in artemisinin-related compounds. These findings demonstrate short-term physiological and metabolic responses to controlled light conditions, providing a basis for evaluating genotype-specific light responses in PFAL systems.