Turning red: Repeated evolution of pigment pathways in land plants

About this opportunity

Production of red pigments is one of the most common responses of plants to environmental stress. Until recently, most stress-induced red pigments were thought to be versions of the anthocyanin flavonoids that are also found in fruit and flowers, with the biosynthetic pathway inherited from the last common ancestor of all land plants. However, following the advent of model species for studying non-seed plants –liverworts, mosses, hornworts, and ferns – new data are challenging this view. Liverworts were found to lack anthocyanins but to have previously uncharacterised red flavonoid pigments with distinct stress-tolerance functions, and other non-seed plants may also have unique red flavonoids. In this project we will investigate the proposal that biosynthesis of red flavonoids has evolved on multiple occasions, with different pigment structures having unique functionalities in stress tolerance and habitat adaptation. Success in the project will enable a unified theory for the evolution of flavonoid biosynthesis to be presented. It will also provide underpinning knowledge on a core stress-tolerance pathway of plants that is the focus of many programmes examining how we may adapt crop plants to our changing climate.

We seek two PhD candidates for this exciting opportunity to investigate the evolution and functioning of red pigments. Both students will be enrolled at the University of Waikato in Hamilton, New Zealand, and supervised by Associate Professor Mike Clearwater (University of Waikato) and Drs Kevin Davies and Nick Albert (Bioeconomy Science Institute, BSI). Both students will be based in the BSI Plant & Food Research laboratories at Palmerston North.

Both candidates will help establish test species of moss, lycophytes, and ferns in culture and prepare extracts for chemical analysis of pigment structures by staff at BSI Auckland. PhD candidate One will carry out stress treatments to induce pigmentation, RNAseq analyses to identify pigment biosynthesis gene candidates, and some gene functional assays. PhD candidate Two will conduct the majority of the gene functional assays, establish transformation systems to test gene function using CRISPR-Cas mediated gene knockout, and conduct phylogenetics examining pathway evolution. Both students will have the opportunity to develop their own research questions within the broader outlines of the project.

This project is funded by an award from the New Zealand Marsden Fund (25-PAF-005). Both positions will receive a full PhD stipend of $NZ 35,000 per annum for three years, plus tuition fees, opportunities for conference attendance, and exchange between our laboratories at the University of Waikato, Plant and Food Research Palmerston North and Auckland, and collaborators at the University of Melbourne (Australia) and Boyce Thompson Institute (Cornell, USA).

References:

Davies K, Landi M, van Klink J, Schwinn K, Brummell D, Albert N, Chagne D, Jibran R, Kulshrestha S, Zhou Y, Bowman J. 2022. Evolution and function of red pigmentation in land plants. Annals of Botany 130: 613–636.

Berland H, Albert N, Stavland A, Jordheim M, McGhie T, Zhou Y, Zhang H, Deroles S, Schwinn K, Jordan B, Davies K, Andersen Ø. 2019. Auronidins are a previously unreported class of flavonoid pigments that challenges when anthocyanin biosynthesis evolved in plants. Proceedings of the National Academy of Sciences USA 116: 20232–20239.

Li FW et al. 2018. Fern genomes elucidate land plant evolution and cyanobacterial symbioses. Nature Plants 4: 460-472.

Location

Hamilton, New Zealand

Scholarship Value

Full PhD stipend of $NZ 35,000 per annum for three years, plus tuition fees and student service fees