集胞藻PCC6803 EGY同源基因破坏突变体的构建及表型分析

Construction of sll0862 or slr0643 disrupted mutants and their phenotype analysis in Synechocystis sp. PCC6803

摘要:

摘要：拟南芥中近来发现的定位于叶绿体的膜嵌合金属蛋白酶EGY1影响叶绿体发育与脂肪酸合成，经生物信息学分析，集胞藻PCC6803 (Synechocystis sp. PCC6803)中slr0643、sll0862基因编码同源蛋白。【目的】为了鉴定这两个基因的功能，【方法】本文通过同源重组插入卡那霉素抗性基因、切断目的基因，分别构建了slr0643::km和sll0862::km两种突变体，检测突变体的生理生化表型。【结果】在30℃，20 μE/m2s自养培养下，slr0643::km与野生型相比，早期

关键词:关键词：集胞藻PCC6803;蛋白酶EGY1;同源基因;slr0643;sll0862;突变体;77K荧光

Abstract:

Abstract: Recently a novel membrane-associated metalloprotease EGY1 was found to localize in the chloroplast of Arabidospis and is required for chloroplast development and fatty acid biosynthesis. The genes slr0643 and sll0862 from cyanobacteria Synechocystis sp. PCC6803 encode EGY1 homologs. [Objective] For functional characterization of these two genes, [Methods] disrupted mutants slr0643::km and sll0862::km were constructed by homologous recombination. [Results] Under 30 degree, normal light and autotrophic growth, compared with wild type, slr0643::km showed similar growth rate in the early stage, but emitted less photosystem I (PSI) fluorescence under 77K and the activity of the entire photosynthetic electron transfer chain was only 83% of the wild type, while cells contained normal thylakoid membranes. No significant difference was found between sll0862::km and wild type under this condition. [Conclusion] These results indicated that slr0643 was involved in PSI assembly and photosynthesis directly while sll0862 did not affect assembly of PSI and PSII directly at this stage, which lay a foundation for further exploring their function and mechnism in cyanobacteria.

Key words:Keywords：Synechocystis sp. PCC6803;protease EGY1;homologs;slr0643;sll0862;disrupted mutant;77K fluorescence