Iron-sulfur clusters (Fe-S) have proven to be necessary for plant growth, according to Colorado State University research. Plants involved in the research project grew normally until researchers silenced the CpNifS gene, resulting in plants with yellowish and stunted growth. The research was published last week in the journal "Proceedings of the National Academy of Sciences."
NifS-like proteins have what is known as "cysteine desulfurase activity," which releases sulfur from the amino acid cysteine for the formation of iron-sulfur clusters, said Doug Van Hoewyk, a doctoral researcher in the Pilon-Smith Laboratory, part of the Department of Biology at Colorado State University. These NifS-like proteins are found in all forms of life.
RNAi silencing of the essential chloroplastic CpNifS gene was regulated by dilute ethanol in transgenic Arabidopsis plants, a member of the mustard family. After three weeks of treating the plant with the non-toxic ethanol mixture, the plants’ chlorophyll content was reduced five-fold. Van Hoewyk found if the ethanol treatments were stopped after three weeks, the plant would recover and were able to set a seed. When the ethanol treatments were continued after the three-week period, the plan would ultimately suffer irreversible damage and die before setting seed.
"These results strongly suggest that CpNifS is not only an essential protein to Arabidopsis, but to all plants containing chloroplasts" Van Hoewyk said.
Van Hoewyk plans to continue his research into the effect CpNifS has on plant mitochondria and chloroplast functions.