ViPS Invited Seminar February 2022

Karin Ljung, Umeå Plant Science Centre (UPSC), Swedish University of Agricultural Sciences (SLU), Umeå, Sweden

Date: 16th Februay 2022

Time: 13:00

Title: Roles of plant hormones during root growth and development in relation to nutrient availability and drought stress

Location: Remotely via Zoom

Host: Ari-Pekka Mähönen

Abstract: We are currently studying root development in different plant species in order to understand how processes such as lateral root initiation and development are regulated by internal as well as external factors, e.g. drought stress and nutrient availability.

Auxin (indole-3-acetic acid, IAA) and cytokinins (CKs) are major regulators of plant growth and development. Biosynthesis, conjugation and catabolism regulate, together with transport, intracellular hormone levels in a highly redundant manner, in order to maintain hormone levels that are optimal for growth and development. The non-uniform distribution of IAA and CKs underlie spatiotemporal coordination of root development and the root responses to environmental stimuli, such as drought stress.

High-resolution measurements of plant hormones at the tissue, cellular and subcellular level can provide valuable insights into their metabolism and transport, and how they regulate specific developmental processes in plants. Using cell-type specific methods for transcript and metabolite profiling, we are currently investigating the early stages of lateral root initiation and development, processes where both IAA and CKs play critical roles. We are also investigating the impact of nutrients, especially nitrogen, on these processes.

Karin's research is focused on the mechanisms and processes regulating plant growth and development, particularly the role of plant hormones in primary and secondary root development. Her group also works on understanding how plants coordinate the growth of their aerial parts with their root systems under different conditions and stresses, and the role that plant hormones play in these processes. Her group has developed ultra-sensitive methods for plant hormone quantification at the tissue, cellular and subcellular level, and are using these methods for studies of auxin and cytokinin biosynthesis, transport and degradation.

Read more about Karin's work

Related publications:

Mateo-Bonmatí E, Casanova-Sáez R, Šimura J, Ljung K. (2021) Broadening the roles of UDP-glycosyltransferases in auxin homeostasis and plant development. New Phytol. 232: 642-654.

Brunoni F, Collani S, Casanova-Sáez R, Šimura J, Karady M, Schmid M, Ljung K, Bellini C (2020) Conifers exhibit a characteristic inactivation of auxin to maintain tissue homeostasis. New Phytol. 226:1753-1765.

Antoniadi I, Novak O, Gelova Z, Johnson A, Plihal O, Simersky R, Mik V, Vain T, Mateo-Bonmati E, Karady M, Pernisova M, Plackova L, Opassathian K, Hejatko J, Robert S, Friml J, Dolezal K, Ljung K, Turnbull C (2020) Cell-surface receptors enable perception of extracellular cytokinins. Nat Commun. 11: 4284.

Šimura J, Antoniadi I, Široká J, Tarkowská D, Strnad M, Ljung K, Novák O. (2018) Plant Hormonomics: Multiple Phytohormone Profiling by Targeted Metabolomics. Plant Physiol. 177:476-489.

Porco S, Pěnčík A, Rashed A, Voß U, Casanova-Sáez R, Bishopp A, Golebiowska A, Bhosale R, Swarup R, Swarup K, Peňáková P, Novák O, Staswick P, Hedden P, Phillips AL, Vissenberg K, Bennett MJ, Ljung K. (2016). Dioxygenase-encoding AtDAO1 gene controls IAA oxidation and homeostasis in Arabidopsis. Proc Natl Acad Sci USA. 113:11016-21.