强光及活性氧对大豆光合作用的影响  

Effects of Strong Light and Active Oxygen on Photosynthesis in Soybean 

作　　者：徐志防[1] 罗广华[1] 王爱国[1] 陈贻竹[1] 郭俊彦[1] 

机构地区：[1]中国科学院华南植物研究所,广州510650

出　　处：《Acta Botanica Sinica》1999年第8期862-866,共5页Acta Botanica Sinica（植物学报：英文版）

基　　金：国家自然科学基金;广东省自然科学基金

摘　　要：利用叶绿素荧光技术研究了强光及活性氧对大豆（ Ｇｌｙｃｉｎｅ ｍａｘ Ｌ．） 光合作用的影响。结果表明，大豆叶片在强光（２０００ μｍｏｌ·ｍ － ２·ｓ－ １） 下照射２ ｈ 后，净光合放氧速率下降。随着处理光强的增加，叶绿素荧光参数Ｆｍ／Ｆｏ、Ｆｖ／ Ｆｍ 、ΦＰＳⅡ、ｑＰ 和ｑＮ 均呈下降趋势。在强光处理大豆叶片时，加入外源活性氧Ｈ２Ｏ２ 、Ｏ－·２ 、·ＯＨ 和１Ｏ２ 后，大豆叶片受到伤害。其中１Ｏ２ 和·ＯＨ 的破坏作用十分明显，表现为Ｆｖ／ Ｆｍ 和ΦＰＳⅡ的明显降低。抗氧化剂ＤＡＢＣＯ、甘露醇、抗坏血酸和组氨酸对强光下的大豆叶片有保护作用，但这种保护作用不强。在暗处理叶片时，超氧物歧化酶（ＳＯＤ）的抑制剂ＤＤＣ对Ｆｍ／ Ｆｏ 和Ｆｖ／Ｆｍ 的影响不大；抗坏血酸过氧化物酶（ＡＰＸ） 的抑制剂ＮａＮ３ 使Ｆｖ／Ｆｏ、Ｆｖ／ Ｆｍ和ΦＰＳⅡ下降明显。强光处理大豆叶片时，ＤＤＣ明显降低Ｆｍ／ Ｆｏ、Ｆｖ／ Ｆｍ 和ΦＰＳⅡ，ＮａＮ３ 降低Ｆｍ／ Ｆｏ、Ｆｖ／ Ｆｍ 和ΦＰＳⅡ的作用则更大。据此推测，在强光下大豆发生了光抑制。With the use of chlorophyll fluorescence technique, it was found that the net photosynthetic oxygen evolution rate decreased after strong light (2?000 μmol·m -2 ·s -1 ) treatment for two hours in soybean ( Glycine max L.) leaves. The chlorophyll fluorescence parameters, F m/F o 、 F v/F m 、ΦPSⅡ、 q P and q N decreased along with the increase of light intensity. In strong light, exogenous active oxygen H 2O 2、O -· 2、·OH and 1O 2 were harmful to soybean leaves. The destruction of 1O 2 and ·OH to leaves was most evident, as was shown that F v/F m and ΦPSⅡdecreased significantly. The antioxidants DABCO, mannitol, ascorbate and histidine protected the leaves, but weakly, from strong light. In darkness, the SOD inhibitor sodium diethyldithiocar_bamate (DDC) had no significant effect on F m/F o and F v/F m , but NaN 3, the ascorbate peroxidase (APX) inhibitor, significantly decreased F m/F o 、 F v/F m and ΦPSⅡ. In strong light, however, both DDC and NaN 3 reduced the above_mentioned fluorescence parameters, but NaN 3 was more effective than DDC. The results suggested that photoinhibition did take place in soybean leaves under strong light, and it was related to active oxygen in vivo .

关 键 词：光抑制 活性氧 强光 叶绿素荧光 大豆 

分 类 号：S565.101[农业科学—作物学]