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Researchers at the Max Planck Institute and the Consejo Superior de Investigaciones Científicas (CSIC) have identified a gene involved in regulation of flowering in perennial plants (those that live several years). The work, published in the journal Nature, provides a better understanding of the molecular mechanisms that determine the reproductive Advertisement differences between annuals and perennials, a fundamental problem in plant biology. Advertisement

The team, led by George Coupland Max Planck Institute, has identified the gene PEP1 as a gene repressor of flowering in perennial species Arabis alpina. In addition, they compared its performance with that of the FLC gene, the orthologous (genes that descended from a common gene) in Arabidopsis thaliana, a model species for studying the control of flowering in annual plants.

The study noted that although the expression of both genes is repressed by low winter temperatures in the case of annual plants such repression is permanent, whereas in the case of perennials, the suppression of the gene is transient, so that the plant returns to its vegetative state with rising temperatures.

Carlos Alonso Blanco, Centro Nacional de Biotecnología (CSIC in Madrid's center), explains the importance of research: "This mechanism may explain the different regulation of the onset of flowering among the annuals and perennials, a fundamental problem in reproductive biology of plants. In addition, it can shed light on how they have evolved different forms of plant life. "

The study has also served to make the first analysis of the development at the molecular level in species Arabis alpina, a plant selected by researchers because of the same phylogenetic family (crucifer) to Arabidopsis thaliana, where the annual species have been made most studies of regulation of flowering. The analysis has shown the potential of Arabis alpina as a model for the study of development processes specific to perennial plants.

The regulation of initiation of flowering is a crucial process in the life cycle of plants, as it determines the success of its reproduction. This process is regulated by several environmental factors, such as low temperatures during the winter season and, although widely studied in annual plants, it has not been in perennial plants. Low temperatures suppress gene expression repressors of flowering in annual and perennial plants (FLC and PEP1) by modifications of chromatin, the structure that organizes the genetic material. Chromatin, which forms the chromosomes, is formed by a combination of DNA, RNA and proteins. Basically, DNA is not naked in the cell nucleus, but a kind of coiled around proteins called histones, forming chromatin. The modifications in histones, called epigenetic changes, are one of the factors involved in regulating the function of genes.

This study shows that some modifications of chromatin caused by low temperatures are permanent in the case of annuals, but transient in the case of perennials, allowing them to return to a vegetative state. To this group belong some herbaceous plants and the vast majority of the wood.