CaCl2对UV-B辐射下菠菜叶片光合特性的影响

Effect of CaCl2 on photosynthetic characteristic of Spinacia oleracea under enhanced UV-B radiation

关键词:  菠菜  UV-B  CaCl₂  光合膜  电子传递链

Key words:  Spinacia oleracea  UV-B radiation  CaCl₂  photosyntheic membrane  electron transport chain

摘要:

以“丹麦旺盛菠菜”为材料,通过UV-B和CaCl₂复合处理,测定光合色素含量、Hill反应活力、叶绿素荧光、MDA含量和抗氧化酶活性等参数,探讨了CaCl₂对UV-B辐射下菠菜叶片电子传递链和光合膜酶保护系统的影响。结果表明,UV-B处理下,光合色素含量、chl/car、类囊体膜上PSII潜在活性(Fv/Fo)、光化学淬灭系数(qP)、非光化学淬灭系数(qN)、PSII光量子产量(ΦPSⅡ)、原初光能转化效率(Fv/Fm),以及Hill反应活力等降低,chla/chlb和MDA含量升高; 喷洒CaCl₂可不同程度缓解UV-B的伤害。不同处理下,POD、SOD和CAT活性的变化呈现补偿效应。UV-B强度与菠菜叶片PSII功能受损程度呈正相关,CaCl₂则主要通过提高chlb含量、类囊体膜上的光量子产量和POD活性,以缓解伤害。重度UV-B辐射下,CaCl₂使chlb含量显著提高可能是导致PSII捕光效率提高的重要因素。

Abstract:

In order to reveal the effect of CaCl₂ on photosynthetic characteristic of Spinacia oleracea under the enhanced UV-B radiation,the photosynthetic pigments,chlorophyll fluorescence,Hill reaction activity and MDA content were determined. The results showed that the treatments could decrease the content of chlorophyll a,chlorophyll b,total chlorophyll,potential activity of PSII(Fv/Fo),photochemical quenching(qP)and non-photochemical quenching(qN),light quantum yield of PSII(ΦPSⅡ),efficiency of primary conversion of light energy(Fv/Fm)on thylakoid membrane,and the activity of Hill reaction,whereas,the treatments could increase chl/car,and the content of MDA. The damage of spinach leaves caused by UV-B was relieved by CaCl₂.With different treatments the change of the activity of SOD,POD,CAT was compensatory effect.The relationship between the UV-B intensity and the damaged degree of PSII function of spinach leaves was positive correlation. It appeared that the most primary action by CaCl₂ radiation occured at the chlb content in total photosyntheic pigments,the light quantum yield and the activity of POD.Under the high UV-B stress,CaCl₂ caused the chlorophyll b increase,which was the most important reason that efficiency of PSII capture light could raise.