Protein clue into rice seed development gene
doi:10.1038/nindia.2014.107 Published online 12 August 2014
Scientists trying to understand the role of a gene responsible for seed development in cereals have discovered previously unknown ways in which the gene works to shape up a rice grain. They have found the molecular basis of why the gene OsMADS29, a major regulator of seed development, expresses itself in a unique way – first by producting RNA on day one of the seed’s life and then by producing the protein on day four1.
Earlier research had found that the gene expressed specifically in seeds in this unique way. Scientists from University of Delhi and Guru Gobind Singh Indraprastha University have now shown that this happens because the OsMADS29 gene is regulated at an additional level after protein production.
The protein does not move into the nucleus actively when present as a single entity. Only when two moieties of OsMADS 29 protein come together to make a dimer, the protein gets actively transported into the nucleus. This is in contrast to a previous study that said the protein can move into the nucleus even as a single entity.
Lead researcher Sanjay Kapoor says they had to repeat the experiments several times to be able to prove their theory.
OsMADS29 in turn controls many genes that shape the rice seeds we eat. “We believe that it targets close to 350 genes that fall in four main pathways: cytokinin metabolism, auxin signalling, plastid biogenesis and starch metabolism,” Kapoor says. The team is now working on those genes downstream to OsMADS29 to get some more clues into seed development in cereals.
1. Nayar, S. et al.
Post-translational regulation of rice MADS29 function: homodimerization or binary interactions with other seed-expressed MADS proteins modulate its translocation into the nucleus J. Exp. Bot.
(2014) doi: 10.1093/jxb/eru296