Eshchar Mizrachi

Tuesday 25 October 2022 | 12:00 noon – Cape Town, SOUTH AFRICA

Department of Biochemistry, Genetics and Microbiology and Forestry and Agricultural Biotechnology Institute, University of Pretoria, SOUTH AFRICA

Understanding molecular mechanisms for nitrogen and phosphorus acquisition in indigenous South African plants

(Host L. Donaldson)

The African Plant Systems Biology for the Bioeconomy Research Progamme explores development, primary and secondary metabolism of indigenous and endemic plant species, using multi-‘omics, systems biology and evo-devo approaches. A primary focus is the exploration of independently evolved strategies for nitrogen and phosphorus acquisition in low nutrient environments. To this end, we have produced a comprehensive gene expression atlas for the cycad Encephalartus natalensis to better understand how these plants – uniquely so in the seed plants – are able to form symbiosis with cyanobacteria in specialized roots for nitrogen acquisition. We have also completed the first chromosome-level, fully annotated genome of an endemic South African and Fynbos plant species – the King Protea, Protea cynaroides. This marks a beginning of several project underway to sequence reference genomes for economically, ecologically and culturally important South African endemic plant species, particularly those from the Fynbos biome. The Protea cynaroides genome has proven useful both for the discovery, role and timing of whole- genome duplications in basal Eudicots, as well as providing causal mechanisms for the Family (and indeed Order’s) inability to form mycorrhizal associations for nutrient acquisition. This reference genome and several other being sequenced currently also provide the basis for a deep understanding and modelling of the regulation and development of phosphorus mining roots – a trait that has independently evolved several times both in Eudicots (Proteaceae, legumes and some cacti) and monocots (restios, sedges and Vellozeacae), and one which has strong potential for biotechnological improvement of crops in the coming decades.