Séminaire IBIP
Les séminaires ont lieu sur le Campus Montpellier SupAgro/INRA de La Gaillarde (2, place P. Viala Montpellier)

Jeudi 17 septembre 2026 à 14h, Amphi 206

Phosphorus-mining strategies of cluster-root-forming species naturally occurring severely phosphorus impoverished soils.

Cluster roots are specialized root structures that represent an evolutionary adaptation to severely phosphorus (P)-impoverished environments. I have been studying cluster roots, particularly those of Proteaceae native to southwestern Australia, from physiological, molecular biological, and ecophysiological perspectives. In this seminar, I will present the following five topics, ranging from P-acquisition mechanisms to the developmental regulation of cluster roots, and conclude with future research directions that I would like to pursue in collaboration with the Benjamin Peret team.

1. How does Hakea laurina,a cluster-root-forming Proteaceae, achieve rapid carboxylate exudation? By exploring the transcriptome of cluster roots and identifying a malate transporter (HalALMT1), I investigated the molecular mechanisms underlying carboxylate release and proposed a possible adaptation to extremely P-limited conditions.
2. Divergent P-mining strategies between two morphological distinct types of cluster roots (simple and compound cluster roots).By combined fieldwork with glasshouse pot experiments, I identified contrasting P-mining strategies associated with simple and compound cluster roots. Although both roots are highly adapted to severely P-impoverished soils, they appear to employ different strategies for P acquisition.
3. Local physiological responses of cluster roots to locally-supplied phytate.Using a rhizobox cultivation system, I investigated spatially localized physiological responses and gene expression under soil conditions.  Hakea laurina produced more cluster roots and enhanced acid phosphatase activity in response to locally supplied phytate, suggesting that cluster-root formation and function can be locally regulated by the availability and form of soil P.
4. Are cluster-root traits transferable between plant species? Insights from reciprocal grafting between white and blue lupin.Using grafting between cluster-root-forming white lupin (Lupinus albus) and non-cluster-root-forming blue lupin ( angustifolius), white lupin rootstock conferred cluster-root-associated traits, including enhanced carboxylate release and acid phosphatase activity, and improved growth and P uptake under low P conditions.
5. Future work: Understanding the developmental regulation of cluster roots.Based on the developmental roles of LBD16-family transcription factors in lateral roots and nodules, I am investigating whether LBD16 homologs also regulate cluster-rootlet formation in white lupin. I will introduce our current results and discuss future experiments in collaboration with the Benjamin Peret team.

Contact : Benjamin Péret