Functional comparison of catalase genes in the elimination of photorespiratory H2O2 using promoter- and 3'-untranslated region exchange experiments in the Arabidopsis cat2 photorespiratory mutant
Functional comparison of catalase genes in the elimination of photorespiratory H2O2 using promoter- and 3'-untranslated region exchange experiments in the Arabidopsis cat2 photorespiratory mutant
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DOI：
10.1111/j.1365-3040.2010.02171.x
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发表时间：
2010-10-01
影响因子：
7.3
通讯作者：
Lu, Ying-Tang
中科院分区：
文献类型：
--
作者：
Hu, Ye-Qin;Liu, Sheng;Lu, Ying-Tang
C-3植物叶片中与光呼吸相关的H_2O_2产量占总H_2O_2的大部分，并且主要被过氧化氢酶清除。在拟南芥中，缺少CAT2，而不是CAT1或Cat3，会导致生长抑制和叶片中过氧化氢的显著积累。为了评估单独的过氧化氢酶基因及其启动子对过氧化氢酶功能的贡献，我们研究了在Cat2突变背景下表达异源CAT启动子的拟南芥衍生物的生长抑制和H_2O_2积累表型。CAT2启动子的表达恢复了Cat2-1突变体的野生型表型，而CAT1和Cat3启动子驱动的CAT2表达不能恢复野生型。CAT2启动子的异位表达也恢复了正常的表型，不同于CAT1需要用CAT2的3‘非翻译区(UTR)替换CAT1。这些结果表明，CAT2的光呼吸作用主要取决于其启动子活性的调节。在光呼吸条件下，CAT2的3‘端非编码区对于控制CAT2蛋白水平是至关重要的。对异源四异构体过氧化氢酶同工酶组成的鉴定表明，CAT2、CAT1和Cat3之间存在一定的功能冗余。
Photorespiration-associated production of H2O2 accounts for the majority of total H2O2 in leaves of C-3 plants and is mainly eliminated by catalases. In Arabidopsis, lack of CAT2, but not CAT1 or CAT3, results in growth suppression and a marked accumulation of H2O2 in leaves. To evaluate the contribution of individual catalase genes and their promoters to catalase function, we investigated the growth suppression and H2O2 accumulation phenotypes of Arabidopsis derivatives expressing catalase genes from heterologous CAT promoters in a cat2 mutant background. The expression of CAT2 from the CAT2 promoter restored the wild-type phenotype in a cat2-1 mutant, while CAT1 and CAT3 promoter-driven expression of CAT2 did not. Ectopic expression of CAT3 from the CAT2 promoter also restored the normal phenotype, unlike that of CAT1 which required replacement of the CAT1 3'-untranslated region (UTR) with that of CAT2. These results demonstrated that the photorespiratory role of CAT2 is determined mainly by the regulation of its promoter activity. The 3'-UTR of CAT2 was vital for controlling CAT2 protein levels under photorespiratory conditions. Identification of component of heterotetramers catalase isoforms suggested that there is some functional redundancy between CAT2 and CAT1 and CAT3.