Marcelo Yanovsky, researcher of the CONICET at the Instituto de Investigaciones Bioquímicas de Buenos Aires (IIBBA, CONICET-IIBFL) [Institute of Biochemical Research of Buenos Aires] and his lab team proved that LSM genes, which are present in all eukaryotic organisms ranging from yeast to humans, are controlled by a biological clock. Experts affirm that faults in its function alter circadian rhythms not only in the plant world but also in in vitro culture human cells.
LSM are a family of RNA-binding proteins that are found in almost all organisms. “These genes are involved in a core mechanism that is found in every eukaryotic cells, known as splicing. Our findings make an association between the control of rhythms by the clock with the splicing processing of a genes’ subgroup”, the scientist comments. Yanovsky is the Head of the Comparative Genomics of Plant Development Laboratory at the Fundación Instituto Leloir, in Buenos Aires.
For Yanovsky, the circadian rhythms are generated by a small group of genes called clock genes, which interact and regulate each other. In order to fulfil their biological function, the genes have to express and translate into a protein. “Among the most traditional circadian rhythms, we can find the sleep-wake cycle rhythms in humans, the locomotive activities rhythms in insects, and the rhythms in the positions of leaves in diverse plant species”, he explains.
Furthermore, the researcher describes that the circadian rhythms are maintained even when the organisms are transferred to other places where they are isolated from the natural light and temperature cycles. Rhythms also remain oscillating with periods close to 24 hours under constant environmental conditions. “This shows that those rhythms are produced by an endogenous clock”, the expert remarks.
This characterization was possible thanks to a cutting edge equipment available at the Instituto de Agrobiotecnología Rosario (INDEAR) [Institute for Agrobiotechnology of Rosario], that allowed researchers to massively sequence millions of RNAm molecules. Therefore, scientists were able to simultaneously quantify the abundance of these molecules and identify different processing variants.
“With this information, we were able to find that the LSM4 and LSM5 genes do not impact the processing and the expression of all the plants’ genes in the same way, they mainly affect a subgroup of genes linked to processes such as the biological rhythm and the responses to abiotic stress like cold and drought”, the researcher comments. Besides, this allows plants to improve their growth and development in response to recurring daily and seasonal changes in the environment.
This finding reveals the mechanisms that regulate the biological rhythms in plants, allowing scientists to obtain more genetic tools to enhance the growth and development of farming in different geographical regions and particularly in different latitudes.
“The circadian clock is part of the machinery that allows plants to measure changes during the lighted period of day, what varies considerably throughout the year as we move away from the Equator. In this way plans are able to anticipate seasons and coordinate their development and growth with the most favourable times of the year”, Yanovsky states.
To understand the regulation of biological rhythms in animals could be valuable to reduce diseases connected with the bad performance of the clocks such as some sleep disorders. Nevertheless, Yanovsky highlights that this finding is still far from impacting on concrete applications for agricultural or health issues.
By Douglas Mac Donald.
About the research
Marcelo Yanovsky. CONICET independent researcher. Head of the Comparative Genomics of Plant Development Laboratory at the Leloir Institute Foundation.
Soledad Perez Santangelo. CONICET doctoral fellow.
Estefania Mancini. Doctoral fellow at the Agencia Nacional de Promoción Científica y Tecnológica (ANPCyT).
Gustavo Schlaen. Postdoctoral fellow at the Fundación Bunge y Born.
Ariel Chernomoretz. CONICET associate researcher. Head of Bioinformatics Laboratory at the Leloir Institute Foundation.
John Hogenesch. University of Pennsylvania.
Lauren Francey. University of Pennsylvania.