Crop Biotech Update

OSOTP 51 Mutation in Rice Leads to Impairment of PSI Complex

February 24, 2012

Gene expression of chloroplasts is regulated by multiple nuclear-encoded proteins. Jian-Wei Ye of the Chinese Academy of Sciences and colleagues isolated a rice mutant osotp51 with significant reduction in photosystem I (PSI), a cluster of chlorophylls that harvest light energy.

The osotp51 was found to be sensitive to light and produces more reactive oxygen species, which could cause destruction of cell structures. The leaves turned less green (almost albino) when exposed to a light intensity of 40 μmol photons/m2 per s. The leaves exhibited the same color with the wild-type when grown on much lower light intensity (4 μmol photons/m2 per s).

The researchers also observed that the level of PSI and PSII dimer was significantly decreased in ostp51. Thus, mutation of ostp51 indirectly leads to widespread alteration of PSI, as well as extreme photoinhibition, and finally dies, even when exposed under low light intensity.

Subscribers of Journal of Integrative Plant Biology may access the research article at