UP researchers unravel gene networks driving wood formation in trees

For millennia wood has played an integral role in the development of human civilisation, providing a source of energy and raw materials for building, furniture, industry and art.

Today, planted forests produce an important renewable feedstock (wood) that forms the basis of a multi-billion dollar forest products industry, providing timber, pulp, paper, textiles and a myriad of other bio-based products. As we begin to move away from a fossil carbon economy, wood as a sustainable source of biomaterials and bioenergy, is increasing in importance. How trees produce vast amounts of wood and how to change the properties of wood to suit various end uses are questions that have been difficult to pursue in trees, due to their large sizes and long life cycles. The advent of genomics technologies allowing the profiling of thousands of genes, even in difficult to analyse tissues, such as wood from mature trees, promises to overcome these hurdles.

A team of researchers in the Department of Genetics at the University of Pretoria (UP) consisting of Dr Eshchar Mizrachi, Dr Nanette Christie and Prof Zander Myburg, together with collaborators in Belgium, Canada and the USA, are reporting one of the first large-scale, integrated analyses of 10 000s of genes profiled in the developing wood of plantation trees. In their paper, published in the prestigious journal Proceedings of the National Academy of Sciences of the United States of America (Mizrachi et al. PNAS, 17 January 2017) the international team describes how they have used network-based approaches (connecting genes with similar expression and functions) to unravel the molecular basis of wood formation. In particular, the team pioneers a new approach, known as systems genetics, which leverages the power of genetics in large numbers of trees.

For their project the team, led by Prof Myburg, sampled genetic materials from developing wood of 156 Eucalyptus trees and profiled the expression of nearly 30 000 genes in each tree, allowing them to identify gene networks important for structural and chemical properties of different woodtypes. This information can now be used for molecular breeding or genetic engineering of trees in an effort to develop a new generation of woody biomass crops, supporting a thriving and sustainable bio-based economy.

This work was supported by the Department of Science and Technology (DST), the National Research Foundation (NRF) and by Sappi through the Forest Molecular Genetics (FMG) Programme at UP.

Paper URL: http://www.pnas.org/content/early/2017/01/12/1620119114.full

Twitter: http://www.pnas.org/cgi/content/long/1620119114v1

Prof Myburg profile: http://www.fabinet.up.ac.za/zmyburg

FMG: http://www.fabinet.up.ac.za/index.php/research-groups/forest-molecular-genetics

https://twitter.com/FMG_UP

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Researchers

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  Professor Eshchar Mizrachi

  Professor Eshchar Mizrachi completed his undergraduate studies as well as his honours, master’s and PhD degrees at the University of Pretoria (UP). He has been employed at the University since 2006, was appointed as a senior lecturer in 2013 and as associate professor in 2019.

  Prof Mizrachi says that UP is home to several world-class institutes and facilities that support his area of interest: genomics, bioinformatics and biotechnology. One of his main personal drivers in his career is empowering early-career researchers in Africa and around the world,  and doing research that has an impact on society. UP, he adds, creates spaces and initiatives that foster transdisciplinary research in Africa.

  Recently, his laboratory has led a multi-lab collaboration to sequence the genome of the king protea (Protea cynaroides), South Africa’s national flower and an iconic representative of the country’s biodiversity and the Cape Floral Kingdom. The genome opens up research opportunities to better understand the ecology, evolution and conservation of protea species and their relatives, and enables new horticulture research.

  “My research focuses on sequencing the genomes of indigenous South African and African plant species and modelling complex biological processes, such as carbon allocation and partitioning in plant biomass formation and specialised roots for the acquisition of phosphorus and nitrogen in nutrient-poor soils,” Prof Mizrachi explains. He adds that this methodology can be applied broadly to answer questions about how novel pathways in plants are regulated by gene networks for the production of important chemical compounds.

  “In the past decade or so, a convergence of technologies, computational capacity and a global drive for a more sustainable bioeconomy has highlighted the need to study and understand fundamental plant biology and evolution,” he says. Prof Mizrachi believes that his field of research contributes to the betterment of the world because the sequencing of plant genomes and the characterisation of the function of genes and gene networks that control plant traits such as growth, development and nutrient acquisition are critical for conservation efforts, biotechnology in agriculture and forestry, and for synthetic biology applications for novel products such as pharmaceuticals and nutraceuticals.

  “I believe we have a moral responsibility in South Africa to study our indigenous plant biodiversity and connect our citizens to it,” he says. With 20 000 to 25 000 plant species, many of which originate in and/or occur exclusively in the country, South Africa is in the top five countries in the world for plant biodiversity. Despite this, the legacy of systemic inequalities is preventing knowledge about our rich biodiversity from reaching most of South Africa’s citizens, especially at a young age. We are engaging with stakeholders in the creative industries to find new ways to foster these connections.”  

  He has the following message for school learners or undergraduates: “Despite my lifelong love of nature and having researched plants for more than 15 years, it is important to note that I did not study biology in high school, and only really began studying plant biology after my master’s degree. Don’t ever think it’s too late to pursue something you are interested in or curious about.”

  Prof Mizrachi hopes that his research contributes to answering fundamental questions about plant development and evolution, and leads to a broader interest from the public to engage with and value the natural world, particularly the amazing plant biodiversity that is around us.

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  UP researchers unravel gene networks driving wood formation in trees