短时强光对绿萝快速叶绿素荧光诱导动力学特性的影响

EFFECTS OF SHORT-TERM STRONG LIGHT ON THE CHLOROPHYLL FLUORESCENCE TRANSIENT IN LEAVES OF EPIPREMNUM AUREUM

本研究以室内培养的阴生植物绿萝(Epipremnum aureum)为实验材料,将绿萝于7月晴天上午8:30-9:30置于室外全光照环境下(光照度21000~34500 lux)处理1.0 h,然后移入室内弱光(最大光照度3600 lux)恢复48 h。于处理不同时期对绿萝叶片进行快速叶绿素荧光诱导动力学曲线的测定,通过比较叶片快速叶绿素荧光诱导动力学特性的变化,以探索绿萝叶片光合机构对短时强光胁迫的响应特征。结果表明:短时强光胁迫导致绿萝叶片光抑制(Fv/Fm)发生,并引起叶片光合性能指数(PIABS)下降,室内弱光有利于Fv/Fm和PIABS的恢复,但PIABS恢复慢于Fv/Fm。短时强光胁迫并未对PSII供体侧放氧复合体(OEC)和PSI反应中心产生影响,但造成PSII反应中心不可逆失活。短时强光使得叶片单位面积内有活性的PSII反应中心数量(RC/CS)下降,从而降低了叶片单位面积吸收的光能(ABS/CS)、捕获的光能(TRo/CS)和进行电子传递的能量(ETo/CS),且其影响在短时间内难以恢复。短时强光虽然降低了捕获光能用于电子传递的量子产额(φEo),但诱导了PSII受体侧PQ库容量(Sm)的增大,这有利于维持光合电子传递,是绿萝对短时强光的应急适应性反应。

In this study,Epipremnum aureum cultivated in the room was used as the research material.On a sunny day in July,E.aureum was placed outdoor under the natural sunlight environment(illumination:21000~34500 lux)for 1h from 8:30-9:30 and then moved indoors and recovered under weak light(the maximum illumination:3600 lux)for 48h.In order to explore the response of photosynthetic apparatus of E.aureum to short-term strong light stress,chlorophyll fluorescence transient curve(OJIP)in leaves of E.aureum were compared at different stages of the treatments.The results showed that short-term strong light caused photoinhibition(Fv/Fm)and reduced performance index(PIABS),which would be optimized by weak light during the recovery period,however,the recovery of PIABS was slower than that of Fv/Fm.Short-term strong light did not affect the PSII donor side oxygen-evolving complex(OEC)and PSI reaction centers,but caused irreversible inactivation of PSII reaction centers.Short-term strong light decreased the number of active PSII reaction centers per unit area(RC/CS),thus reduced the specific energy fluxes per unit area for absorption(ABS/CS),trapping(TRo/CS)and electron transport(ETo/CS),which were not recovered in short time.Short-term strong light also reduced quantum yield for electron transport(φEo),but induced the increase of PQ pool capacity(Sm),which were the emergency adaptive response for short-term strong light to maintain photosynthetic electron transfer.