Cells, Genes & Molecules Plants & People

State of the World’s Plants and Fungi: finding useful plants and fungi

There is great potential for further utilizing the global genetic diversity to advance the common good.

State of the World’s Plants and Fungi report was compiled by 210 researchers from 42 countries to provide an in-depth look at how we can protect and sustainably use the world’s plants and fungi for the benefit of people and the planet. One of the main chapters in the report focuses on how to select and improve fungi and plants for human use.

Dr Paul Kersey with 11 colleagues have reviewed molecular techniques for selecting and improving plants and fungi with useful properties. The researchers highlight interesting examples such as using stacking multiple biosynthetic genes to increase easily fermentable biosugars whilst reducing lignin content of biofuel crops, using genes involved in tomato domestication for enhance productivity in groundcherries (Physalis pruinosa) and how genes from two Aspergillus species could lead to the production of an insecticide compound in a third Aspergillus species. 

The researchers firstly reviewed the tools in genomics (e.g. marker assisted selection, genomic selection, direct genetic modification, CRISPR/Cas genome editing) for plants and fungi. Whilst genetically modified organisms (GMO) continuously receive bad press and are not accepted by the public in most countries, they provide possibilities to reduce insecticides, increase nutrition, increase N-fixation without synthetic fertilisers, cope with environmental stresses and overall, increase food security worldwide.

Pathways of selecting plant genetic resources for improving useful properties of crops from underutilised crops, crop wild relatives and wild ancestors. Conserving the genetic diversity is crucial to select land races and improve cultivars through either conventional breeding or genetic modification. Source: Kersey et al., 2020

Out of the estimated of 2.2–3.8 million fungi species, only 148,000 species of fungi have been named. Breeding fungal strains is a complicated process due to their life cycles and sexual incompatibilities but some hybrid strains can be used for making new forms of beer and biofuels. In the last 15 years of fungal genome sequencing, scientists have been focusing on understanding biosynthetic pathways and the production of secondary metabolites. The “one strain many compounds” (OSMAC) framework of growing fungal strains under different conditions and growing fungi-fungi or fungi-bacteria together can be used to produce new compounds.

Whilst only 277 fungal biosynthetic pathways are currently described, there are great potentials of genomic studies in the future. “[C]himeric enzymes and combinatorial expression of biosynthetic genes can also result in novel derivatives of known compounds as shown for fungal macrolide lactones with potential anti‐tumor, anti‐malarial, and anti‐bacterial activities and fungal cyclodepsipeptides with novel antiparasitic activity to treat, for example, the potentially fatal Chagas disease and Leishmaniasis”, Kersey and colleagues wrote.

Co-cultivation of fungal strains together can yield new compounds with important properties. Source: Adrian J. Hunter/WikimediaCommons

The scientists made a case for conserving plant and fungal genetic resources whilst also highlighting that 8-20% of angiosperm species produce desiccation-sensitive seeds that makes them unsuitable for seed bank conservation. Alternative storage includes cryopreservation and pollen storage. To quickly evaluate the potential of crop wild relatives and landraces for crop breeding programs, Focused Identification of Germplasm Strategy (FIGS) can be used to combine genetic, geospatial analyses with agro-ecological data for predictive characterisation. 

“DivSeek (https://divseekintl.org), a global initiative bringing together most of the world’s largest seed banks, aims to develop standards for the generation and curation of genotypic and phenotypic information and provide the link between plant breeders and public germplasm collections”, Kersey and colleagues added.

This review presented many exciting possibilities of selecting and engineering plants and fungi for human uses but the researchers highlight that “[t]he obstacles to delivering this vision are as much sociological as they are technical, including the linkage of access to genetic material (and derived information) to benefit sharing, and are being discussed in the context of the Convention on Biological Diversity (CBD), amongst other forums.”

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