Hot off the press! New research explores rare heat patterns in plants in largest study of its kind

Release date: 20 June 2023

  • New research finds that the Amorphophallus genus of plants can warm up themselves up to 21˚C above ambient temperature; experts also found a surprising variation in temperature patterns across different species
  • This is the largest study of its kind to document thermogenesis right across the genus Amorphophallus and to investigate the phenomenon in an evolutionary context
  • By developing analytical tools, experts compared the temperature patterns across a large number of plant species
An inflorescence under a thermal camera shows plant heating.
A. longituberosus showing an impressive heat of 21.7c above air temperature under a thermal camera © Cyrille Claudel, Botanic Garden Hamburg

In a new study published in The Plant Journal, researchers at the Royal Botanic Gardens, Kew, University of Hamburg and partners have developed new approaches to compare and investigate the ability of plants in the genus Amorphophallus to produce their own heat, exploring the highly varied temperature patterns and their evolutionary significance. 

This ability to generate metabolic heat – known as thermogenesis – is much more common in animals and birds than in plants, but it has been documented in some plant families, most prominently the Araceae, also known as the arum family. The process of thermogenesis happens during the flowering stage of the plant and plays a role in the pollination process. Previously, it had only been recorded in a couple of species of Amorphophallus, which is one of the largest genera of Araceae, currently comprising 237 species.  Amorphophallus is widely distributed across Africa and Australasia and is known to be morphologically diverse. A selection of Amorphophallus species develop large, dark inflorescences – cluster of flowers – accompanied by foul smells such as the impressive titan arum, which recently flowered at Kew Gardens.

For over 10 years as part of this study experts have been measuring the temperature of the plant genus Amorphophallus, with the hope to gather further understanding about the genus’ ability to create heat. A. longituberosus, a sweet-scented tropical species native to Southeast Asia was found to be the warmest temperature as part of the study, exceeding ambient temperature by 21.7°C. Many species of the Amorphophallus genus are considered vulnerable or critically endangered by the IUCN.

Professor Alexandre Antonelli, Director of Science at RBG Kew said: ‘After painstakingly setting up a heat camera and a series of small devices on various Amorphophallus plants at the early stages of this project, I first couldn’t believe my eyes: as inflorescences developed, even some of the tiniest species were producing incredible amounts of heat – something that had never been reported by scientists for those species before. The large variation in heat production among closely related species opens exciting opportunities to examine the chemical pathways to heat production, the genetic architecture involved, and the mechanisms that can switch that function on or off through evolutionary history. This understanding could one day help create more frost-tolerant crops, expanding the growing season in temperate regions. By producing more food on the same land area, we would need less land for agriculture and could increase the protection of biodiversity in other areas.’

Lead author PhD Student at University of Hamburg Cyrille Claudel said: ‘Thermogenesis is rare in plants, which makes it fascinating to study. It occurs particularly often in the arum or aroid family, which contains more thermogenic species than any other. As part of this study, we found the temperature patterns are highly varied across the genera and even the species. The functions of plant thermogenesis have long been debated and it remains a contentious topic. The exact function, the contribution to successful pollination, its evolutionary impact in terms of speciation or species richness, the morphological requirements to thermogenesis are not well investigated, let alone fully understood. Further assessments of the remaining species are urgently needed to guide effective conservation strategies and safeguard the future of these unique and fascinating plants.’

ENDS

Please find high res images linked here: https://we.tl/t-8RfmtaKSM

For interview requests please contact: Charlotte Newell, PR Manager (c.newell@kew.org); or the Press Office (pr@kew.org)

Link to paper: https://onlinelibrary.wiley.com/doi/10.1111/tpj.16343

NOTES TO EDITORS

About Kew Science

Kew Science is the driving force behind RBG Kew’s mission to understand and protect plants and fungi, for the well-being of people and the future of all life on Earth. Over 470 Kew scientists work with partners in more than 100 countries worldwide to halt biodiversity loss, uncover secrets of the natural world, and to conserve and restore the extraordinary diversity of plants and fungi. Kew’s Science Strategy 2021–2025 lays out five scientific priorities to aid these goals: research into the protection of biodiversity through Ecosystem Stewardship, understanding the variety and evolution of traits in plants and fungi through Trait Diversity and Function; digitising and sharing tools to analyse Kew’s scientific collections through Digital Revolution; using new technologies to speed up the naming and characterisation of plants through Accelerated Taxonomy; and cultivating new scientific and commercial partnerships in the UK and globally through Enhanced Partnerships. One of Kew’s greatest international collaborations is the Millennium Seed Bank Partnership, which has to date stored more than 2.4 billion seeds of over 40,000 wild species of plants across the globe. In 2020, Kew scientists estimated in the State of the World’s Plants and Fungi report that 2 in 5 plants globally are threatened with extinction.