Changes in photosynthesis and pigmentation in an agp deletion mutant of the cyanobacterium Synechocystis sp.

Authors: Miao X.^{1, 2}; Wu Q.^{1, 3, 4}; Wu G.¹; Zhao N.¹

Source: Biotechnology Letters, Volume 25, Number 5, March 2003 , pp. 391-396(6)

Publisher: Springer

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Abstract:

The agp gene encoding ADP-glucose pyrophosphorylase is involved in cyanobacterial glycogen synthesis. By in vitro DNA recombination technology, agp deletion mutant (agp^-) of cyanobacterium Synechocystis sp. PCC 6803 was constructed. This mutation led to a complete absence of glycogen biosynthesis. As compared with WT (wild type), a 60% decrease in ratio of the c-phycocyanine/chlorophyll a and no significant change in the carotenoid/chlorophyll a were observed in agp^- cells. The agp^- mutant had 38% less photosynthetic capacity when grown in light over 600 mgr mol m^-2 s^-1. Under lower light intensity, the final biomass of the mutant strain was only 1.1 times of that of the WT strain under mixotrophic condition after 6 d culture. Under higher light intensity, however, the final biomass of the WT strain under mixotrophic conditions was 3 times that of the mutant strain after 6 d culture and 1.5 times under photoautotrophic conditions. The results indicate that there is a minimum requirement for glycogen synthesis for normal growth and development in cyanobacteria.

Keywords: ADP-glucose pyrophosphorylase; agp deletion mutant; glycogen; photosynthesis; Synechocystis sp.

Language: English

Document Type: Research article

Affiliations: 1: Department of Biological Sciences and Biotechnology and Protein Science Laboratory of MOE, Tsinghua University, Beijing 100084, P.R. China 2: Department of Biological Sciences, Ningde Teachers College, Fujian, Ningde 352100, P.R. China 3: Fax: +86-10-62781825 4: E-mail: qingyu@tsinghua.edu.cn

Publication date: 2003-03-01