Effects of Different Irradiance Conditions on Photosynthetic Activity, Photosystem II, Rubisco Enzyme Activity, Chloroplast Ultrastructure, and Chloroplast-Related Gene Expression in Clematis tientaiensis Leaves

Clematis is a perennial ornamental vine known as the “Vine Queen” for its gorgeous floral color and rich flower shape. tientaiensis, an endangered plant, key protected wild plant rare breeding parent of because extremely high value. Light environment one important environmental factors affecting space distribution size C. tientaiensis population. One-year-old homogenous healthy potted plants were grown under four different light intensities (T1: 1800 ± 30/0 µmol m?2 s?1; T2: 1500 T3: 1200 T4: 900 s?1). This study analyzed potential adaptive mechanism in response to irradiance by investigating photosynthesis, rapid curve, chloroplast ultrastructure, Rubisco activase enzyme (RAC), enzyme, amino acids, gene expression treatments. High caused leaves chlorosis yellowing, reduced net photosynthetic rate (Pn), stomatal conductance (Gs), RAC activity; quantum yield unregulated energy dissipation [Y(NO)], increased content eight acids content. The psbA, psbB, psbC, Psb(OEC) down-regulated with decreasing irradiance. results showed that T1 (1800 30 s?1) danger absorbing more than they could use while exhibited good adaptability T3 (1200 irradiance, PSII reaction center RCA enzymes be points stress, which also emphasized importance appropriate management practices promoting growth population expansion tientaiensis.