Biotech Updates

Chinese Research Team Finds Chloroplast Biogenesis Genes in Rice

April 18, 2018

Chloroplast genes are transcribed by the plastid-encoded RNA polymerase (PEP) or nucleus‐encoded RNA polymerase. FRUCTOKINASE‐LIKE PROTEINS (FLNs) are carbohydrate kinases that act as part of the PEP complex. However, the mechanisms underlying FLN activity are quite unknown. In their study, the team of Lei He of the China National Rice Research Institute studied the OsFLN1 gene, a homolog of HSA1/OsFLN2, and the effect of its knockout on chloroplast biogenesis.

The team found that OsFLN1 is localized in the chloroplast. Analysis revealed that OsFLN1 and HSA1/OsFLN2 interact with THIOREDOXINZ (OsTRXz) to regulate chloroplast development. To prove this, the team generated fln1 knockout mutants via CRISPR-Cas9. These mutants exhibited severe albino phenotype and seedling lethality. The team also developed OsTRXz-knockout mutants, which also showed a similar albino and seedling lethality phenotype to that of the fln1 mutants.

Further analysis revealed that the transcription and translation of PEP‐dependent genes were strongly inhibited in fln1 and trxz mutants.

These results show that OsFLN1 and HSA1/OsFLN2 contribute to chloroplast biogenesis and plant growth.

For more information, read the article in Journal of Integrative Plant Biology.