Acknowledgements
We apologise to those authors whose work was unable to be included in this review owing to space limitations. Research in the laboratory of R.V.E. is supported by The New Zealand Government Ministry of Business, Innovation and Employment’s Endeavour Fund, contract C11X1704 ‘Filling the Void’ and for L.J. by NordPlant (NordForsk grant no. 84597). We thank our Plant & Food Research colleagues Kevin Davies for helpful advice on the manuscript and Elysia Arnold and Ben Lawrence for illustrations.