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为探讨乙酰水杨酸(ASA)对增强UV-B辐射条件下长春花光合功能的调控作用,以长春花幼苗为试材,喷施一定浓度的乙酰水杨酸溶液,测定其在UV-B辐射增强下叶绿素含量、光合参数、叶绿素荧光参数、MDA含量及抗氧化酶活性的变化,结果表明:UV-B辐射降低了长春花叶片叶绿素含量、净光合速率(Pn)、原初光能转化效率(Fv/Fm)、光化学猝灭系数(qP)、实际光化学效率(ΦPSⅡ)及光合电子传递速率(ETR),提高了类胡萝卜素的含量和非光化学猝灭系数(qN).UV-B辐射引起了长春花叶片丙二醛(MDA)含量增加,超氧化物歧化酶(SOD)和过氧化物酶(POD)活性升高,过氧化氢酶(CAT)活性降低.2 mg/L的乙酰水杨酸处理则降低了UV-B辐射胁迫下上述指标的变化幅度.分析认为,乙酰水杨酸可能直接或间接地通过清除O2-.而使类囊体膜保持完整及光合色素免受UV-B的伤害,进而使PSⅡ维持较高的光化学活性和电子传递速率,这可能是乙酰水杨酸提高增强UV-B辐射下长春花光合速率的内在原因.
In order to investigate the regulatory effect of acetylsalicylic acid (ASA) on the photosynthetic function of Catharanthus roseus under enhanced UV-B radiation, a certain concentration of acetylsalicylic acid solution was sprayed on the seedling of Catharanthus roseus, The results showed that UV-B radiation reduced chlorophyll content, net photosynthetic rate (Pn), primary light energy conversion efficiency (Pn), photosynthetic rate, photosynthetic rate (Fv / Fm), photochemical quenching coefficient (qP), actual photochemical efficiency (ΦPSⅡ) and photosynthetic electron transfer rate (ETR) increased the content of carotenoids and the non-photochemical quenching coefficient (qN) Caused the increase of malondialdehyde (MDA) content, the activity of superoxide dismutase (SOD) and peroxidase (POD) and the activity of catalase (CAT) Salicylic acid reduced the change range of the above indexes under UV-B radiation stress.According to the analysis, acetylsalicylic acid could directly or indirectly clear the thylakoid membrane and photosynthetic pigment from UV B injury, which in turn PS Ⅱ to maintain high photochemical activity and electricity Transfer rate, which may be enhanced improving the underlying causes of acetylsalicylic acid in Catharanthus spent on-rate of UV-B radiation.