Phosphoenolpyruvate carboxylase (PEPCase), encoded by the PEPC2 gene, is
vital in the production of oxaloacetic acid for tricarboxylic acid (TCA)
cycle. The team of Yanpeng Zhao from the China Agricultural University
recently found that silencing the GhPEPC2 gene using RNAi could regulate oil
and protein accumulation in Cotton seeds.

In the GhPEPC2-silenced plants, the PEPCase activities in immature embryos
were significantly reduced, resulting in a significant increase in oil
content in seed kernels and a decrease in total proteins. Moreover, compared
to wild types, the agronomic traits of transgenic plants were unaffected.

Further analysis of GhPEPC2 transgenic seeds revealed that most lipid
synthesis-related genes were upregulated, and amino acid metabolic-related
genes were downregulated. In addition, the GhPEPC2 transgenic cotton
seedlings also exhibited enhanced Salt tolerance.

These results show that GhPEPC2 can regulate oil content, protein
accumulation and salt tolerance in cotton and possibly in other plants.



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