Cutting edge What’s new in the world of botanical research?

THE CUTTING EDGE

RESEARCHERS WORKING WITH THE AUSTRALIAN INSTITUTE OF BOTANICAL SCIENCE PUBLISH MORE THAN 90 PEER-REVIEWED ARTICLES EACH YEAR. DR BRETT SUMMERELL HIGHLIGHTS A FEW RECENT RESEARCH PROJECTS.

Blue Mountains Botanic Garden waratah and honeyeater SEQUENCING THE GENOME OF THE NSW WARATAH The New South Wales waratah, Telopea speciosissima, is an iconic Australian species that has captivated plant lovers around the world. This species is becoming more and more important as a commercial cut flower crop. As a member of the Proteaceae family that is most abundant in southern Africa and Australia, it is a relic of Gondwana and likely to hold some keys to better understanding the evolution of Australian plants.

For this reason, the waratah was chosen of one of the first Australian plant species to have its complete genome sequenced by the Genomes of Australian Plants program that is supported by Bioplatforms Australia¹. There is great potential for the waratah to be a model for understanding the processes of divergence, environmental adaptation and speciation in Australian plants. Our understanding of these processes can be greatly enhanced by a genome-wide perspective, that will be enabled by a reference genome.

The genome of the waratah is approximately 900 megabase* in length and contains 22 chromosomes. This is similar in size to the macadamia which is the only other publicly available reference genome in the family. The chromosome-level T. speciosissima reference genome will provide an important new genomic resource to support the conservation of flora in Australia and further afield. A reference genome will also accelerate efforts in breeding for traits such as resistance to pests and diseases (e.g. Phytophthora) as well as desirable floral characteristics.

PLANT TRAITS Plant traits are defined as those characteristics that we use to predict a plant’s ability to grow in environments or respond to different threats. They can include different morphological characteristics (flower type, leaf size, height etc) or physiological adaptability (growth rate, temperature sensitivity or water use).

A new and huge paper², involving a number of our scientists and co-lead by our own Dr Hervé Sauquet, outlines the “AusTraits” database – a compilation of values of plant traits for different species of Australian flora.

AusTraits brings together data on 448 traits across 28,640 taxa from field measurements, published literature, taxonomic monographs and individual species descriptions. These traits vary in scope from physiological measures of performance (for example, photosynthetic gas exchange and water-use efficiency) to morphological attributes (such as leaf area, seed mass and plant height) which link to aspects of ecological variation.

AusTraits contains curated and harmonised individual- and specieslevel measurements coupled to, where available, information on site properties and experimental conditions.

It is envisioned that AusTraits will be a lasting ongoing collaborative initiative for easily archiving and sharing trait data. This information is extremely useful for predicting and modelling the response of plants to a rapidly changing environment.

NEW GUIDELINES FOR CONSERVING SEED AND OTHER PLANT TISSUES A new edition of Plant Germplasm Conservation in Australia³, edited by a number of people, including Amelia Yenson Martyn and Cathy Offord, has been published by the Australian Network for Plant Conservation.

These guidelines provide an evidence-based best practice guide for the management of ex situ (off site) collections of seeds, plant tissues, or plants in nurseries and living collections. Many of the chapters in this book were written by the Gardens’ scientists and highlight a lot of our experiences resulting from work at the Australian PlantBank.

The guidelines provide information on genetic issues, nursery management, cryopreservation and seed collection, and are available to download for free at anpc.asn.au/plant-germplasm. The production of the guidelines was supported by the Ian Potter Foundation.

Paper details: 1. Chromosome-level de novo genome assembly of Telopea speciosissima (NSW waratah) using longreads, linked-reads and Hi-C. Molecular Ecology Resources (in press). 2. AusTraits, a curated plant trait database for the Australian flora. Scientific Data 8: 254 nature.com/articles/s41597-021-01006-6. 3. Plant Germplasm Conservation in Australia. Strategies and guidelines for developing, managing and utilising ex situ collections. Third Edition, 2021. *a megabase is a term used in genetics to measure the length (number of base pairs) of a genome segment.