Assessing Factors that Influence Spruce Growth and Lignin Synthesis


Investigations into factors controlling growth and lignin synthesis in spruce have received considerable interest in recent decades, with the Norway spruce in particular being a highly valued model species. Norway spruce is a large coniferous tree native to Central, Northern, and Eastern Europe, and is consumed and processed for a number of both wood-based and chemical-based applications. What’s more, a high proportion of the carbon obtained from terrestrial biomass is stored in the form of the cell walls of wood tissues, specifically in the form of an important phenolic polymer known as lignin.

So, it’s no surprise that efforts have been made to unravel the metabolic pathways involved in spruce growth and lignin production. Leading this research is a team from Tokyo University of Science (TUS), Japan, including professor Kazuyuki Kuchitsu, a renowned expert in reactive oxygen species (ROS). Thanks to their tireless work, recent breakthroughs have been made in uncovering the molecular intricacies behind lignin biosynthesis, particularly the oxidation of monolignols to phenolic radicals, which are then coupled non-enzymatically.

Further experiments revealed that PaRBOH1 — plant RBOHs or NADPH oxidases — has an important role in the last steps of lignin formation and spruce growth, with cytoplasmic NADPH as its electron donor, producing superoxide anions which then dissipate to hydrogen peroxide. To gain a deeper understanding of the regulatory mechanism of PaRBOH1, Prof Kuchitsu worked closely with scientists from the University of Oulu, Finland, Institution Polytechnique UniLaSalle, France, and the Natural Resources Institute Finland (Luke), Finland, to study the connection between calcium ions, phosphorylation, and PaRBOH1, publishing the results in Frontiers of Plant Science.

The research uncovered that PaRBOH1 was directly activated by both calcium ions and phosphorylation, indicating that all seed plants, both gymnosperms and angiosperms, use similar methods to regulate the activity of their RBOHs. Professor Kuchitsu believes their findings can be used to promote the growth of trees, and potentially advance the technologies used to produce useful materials.

The Tokyo University of Science is one of the oldest and most reputable science universities in Japan, being founded in 1881. Located in Tokyo and boasting 16 faculties, it educates thousands of students each year and conducts during cutting-edge research across many scientific fields and industries.

Kazuyuki Kuchitsu, professor at the Tokyo University of Science and leading researcher on ROS in plants, has developed a sterling reputation worldwide for his work in this field. He has taken part in numerous collaborations with universities and organizations in Japan, Finland, and France, and his extensive academic experience in molecular biology and biochemistry has enabled him to research and uncover various previously unknown ROS-related processes in plants.