Siberian Federal University

An international team of scientists from SibFU and the University of Göttingen studied the genetically determined mechanism of seasonal leaf fall in Siberian larch, the only species of the pine family capable of shedding needles in the autumn period. New generation sequencing technologies have made it possible to study this phenomenon at the genome-wide level, to identify and compare the molecular genetic mechanisms of aging of leaves and needles in angiosperms and gymnosperms.

In the course of evolution, both flowering plants and some gymnosperms have developed a special adaptation to winter and unfavorable living conditions, known as deciduous. Of particular interest to science is the Siberian larch (Larix sibirica Ledeb.) — the only tree from the pine family (Pinaceae) capable of shedding needles in the autumn period.

The first author of the publication is a master's student of the Department of Genomics and Bioinformatics of SibFU Anastasia Batalova said that with the help of a comparative analysis of the genomes of evergreen and deciduous trees, it was found that genes controlling proteins that participate in the metabolism of sugars (EXORDIUM LIKE 2 and DORMANCY-ASSOCIATED PROTEIN 1) are represented in the largest quantities in the genome of Siberian larch. EXORDIUM LIKE 2 participates in the perception of signals of reduced carbon availability, which contributes to the launch of recycling of cellular components through autophagy (the so–called process of digestion and reuse of degraded cell components — natural waste recycling) in the process of seasonal aging.

This allows saving the resources of the plant that are lost when the needles are shed and necessary for the subsequent regeneration of new needles in the spring. DORMANCY-ASSOCIATED PROTEIN 1 (DRM1), a low-specific sugar sensor that is also involved in the plant's transition to a state of physiological rest. At the same time, there is an excess of genes in the genomes of evergreen plants that control proteins that function as immune receptors. Those proteins provide resistance to stress and pathogens and may be associated with a longer lifespan of coniferous trees. This supports the role of immune protection in regulating leaf lifespan.

Another important conclusion of scientists was the explanation of the role of the so—called protective genes - representatives of this family control leucine-rich repeats of receptor-like kinases (LRR-RLK). Most likely, they made the main contribution to the difference between evergreen and deciduous plants.

"The genetic regulation of seasonal aging, to which the study is devoted, is a fundamental biological problem related to the programmed cell death and life expectancy. In our opinion, it is very important to understand the evolution of these mechanisms. Solving the problem of genetic regulation of aging is critically important for new discoveries in biomedicine — ultimately, humanity will always strive to live longer. Perhaps we will learn how to solve the problems of longevity with the help from the trees," said the research supervisor, Professor of the Department of Genomics and Bioinformatics of SibFU, Honorary Professor of Siberian Federal University and the University of Göttingen Konstantin Krutovsky. The scientist noted that a comparative study of the genomes of additional plant species is planned in the future, which can provide more detailed information about the genetic differences between evergreen and deciduous species.

The concept and methodology of the study were developed jointly by Krasnoyarsk researchers — Anastasia Batalova, Yulia Putintseva (Department of Biophysics of SibFU) andMikhail Sadovsky (Institute of Computational Modeling SB RAS) under the guidance of professor Konstantin Krutovsky. Calculations and data processing were performed by Dmitry Kuzmin, Head of the Department of High-Performance Computing at the School of Space and Information Technologies, and a researcher at the Department Vadim Sharov.

• Paper in English