Rishikesh Bhalerao (left), Åsa Strand (middle) and Nathaniel Street (right) each lead a project exploring key aspects of plant development, environmental adaptation and resilience (photo credit (from left to right): Andreas Palmén, Vaughan Hurry, Fredrik Larsson).
Last week, the Swedish Research Council announced the recipients of funding under its call for research projects in natural and engineering sciences. Among those selected are three projects led by UPSC researchers Rishikesh Bhalerao, Åsa Strand and Nathaniel Street. Their research explores how trees regulate the timing of bud break in spring, how photosynthesis is established, and the evolutionary innovations that have shaped conifers.
The four-year funding will enable the researchers to build on previous findings and apply new approaches to fundamental questions in plant biology. Their projects will span different scales, from molecular processes in seedlings and trees to genome-wide adaptation mechanisms in conifers, each contributing to a broader understanding of how plants develop and respond to their environment.
Rishikesh and his team want to understand how trees can sense the perfect moment to open their buds in spring. When days slowly warm, temperatures often swing unpredictably between warm and cold. To prevent damage by late frost and still use the short growing season as effectively as possible, plants need to time the opening of their buds carefully. Rishikesh Bhalerao and his team have identified a protein complex that helps plants sense temperature and controls the timing of bud break via plant hormones, which regulate the strength and elasticity of the cell wall.
Together with his team, Rishikesh Bhalerao will investigate the role of this protein complex by combining genetic, cell biological and tree physiological approaches in the model tree species hybrid aspen. Their research will reveal how plants sense and respond to temperature changes at the molecular level helping them to decide when to open their buds in spring and, more broadly, how to time key developmental transitions.
While Rishikesh Bhalerao’s team investigates seasonal timing in trees, Åsa Strand and her group will look into the cellular choreography that enables plants to begin photosynthesis. Turning green and starting photosynthesis is a remarkably complex process for plant cells. The chloroplast, where photosynthesis takes place, was once an independent cell that merged into another cell during evolution. Although many of its genes were transferred to the nucleus of the host cell, it retained a few essential ones, requiring precise coordination between the chloroplast and the nucleus.
Åsa Strand and her team have already identified several key players involved in this communication. Now, they will investigate in more detail how the signals are sent from the chloroplast to the nucleus, how these signals are perceived in the nucleus and how they modify chromatin to activate photosynthetic genes in the nuclear genome. These insights will be included into a model explaining how photosynthesis is established through changes in cellular metabolism.
In contrast to chloroplast genomes, the genomes of conifers such as Norway spruce and Scots pine are enormous - about ten times larger than the human genome. Yet only a small fraction contains actual genes. Nathaniel Street and his colleagues have found that much of the remaining DNA consists of repeated segments, some integrated into regions that control when, where and how strongly genes are switched on. They hypothesise that these duplications give conifers an evolutionary advantage, helping them adapt to changing conditions.
To test this idea, Nathaniel Street and his team will focus on Norway spruce and Scots pine, using advanced genomic and epigenomic techniques to uncover the role of these repeated DNA segments. They will compare their findings with aspen, an angiosperm whose entire genome was duplicated during evolution, and validate their results by genetically modifying Norway spruce. Ultimately, their work will help to understand what makes conifers resilient, providing knowledge that could support sustainable forestry in a changing climate.
Link to the announcement from the Swedish Research Council
The three research projects awarded by the Swedish Research Council within Natural and Engineering Sciences:
• Project: Understanding how trees robustly regulate the timing of bud break in spring
Rishikesh Bhalerao
Umeå Plant Science Centre
Department of Forest Genetics and Plant Physiology
Swedish University of Agricultural Sciences
Email:
https://www.upsc.se/rishikesh_bhalerao
• Project: Establishment of Photosynthesis, a Tale of Two Genomes
Åsa Strand
Umeå Plant Science Centre
Department of Plant Physiology
Umeå University
Email:
https://www.upsc.se/asa_strand
• Project: Con-TEki - Conifer Transposable Elements as key drivers of regulatory innovation
Nathaniel Street
Umeå Plant Science Centre
Department of Plant Physiology
Umeå University
Email:
https://www.upsc.se/nathaniel_street