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The ability of a seed to germinate rapidly and uniformly under different environmental conditions is an important agronomical trait, ensuring homogenous seedling establishment needed for optimal crop production. A key factor that contributes to this trait is the seed’s capacity to remain alive for extended periods of time in the dry state, called longevity. Seeds with elevated longevity will only slowly deteriorate during conservation, retaining high germination vigour. Improving seed quality and better understanding seed longevity are major issues for breeders and farmers. Seed vigour is a complex trait determined by gene x environment interactions that remain poorly understood. To identify loci related to seed longevity, the HAPMAP collection of Medicago truncatula was used to identify associations between SNPs and seed longevity. The objectives of this project is to functionally characterize the genes behind the most highly significant SNPs related to seed longevity. A part of the project will focus on the implication of the glyoxylate cycle and malate in the acquisition of seed longevity during maturation. A previous gene regulatory network study from the group proposed an implication of defense and ABA signalling components in the regulation of seed longevity, A part of my project will focus on understanding whether these components are involved in integrating environmental cues to control developmental transition and this by characterising the function of the candidate gene encoding for a PP2C type of phosphatase.
I graduated as Agronomist in 2006 from the National Institute of Agronomy of Tunisia. My undergraduate research thesis focused on the germination quality of wheat seeds and its relation to the plant yield. After my graduation, I decided to follow an academic research carrier that started with a Master degree at Agrocampus of Rennes in France and later a PhD at the University of Evry in Paris. My PhD project focused on plant signaling through Mitogen-activated protein kinases (MAPK) cascades where I identified hyperactive forms of Arabidopsis MAPKs through a genetic screen in yeast, which helped studying their specific target and functions. For my first post-doctoral experience I moved to the UK at the John Innes Centre where my research aimed at the understanding of the molecular mechanisms behind temperature-induced defense breakdown and the role of the histone variant H2A.Z in this regulation using a combination of genetic, molecular biology and biochemical approaches. My AgreenSkill project focuses on unravelling new regulators of seed longevity with a particular interest in those playing a role in stress response and signaling using a Genome wide association approach.
Genot B, Lang J, Berriri S, Garmier M, Gilard F, Pateyron S, Van Der Streaten D, Hirt H, Colcombet J, 2017. Constitutively Active Arabidopsis MAP Kinase 3 Triggers Defense Responses Involving Salicylic Acid and SUMM2 Resistance Protein. Plant Physiology. 174(2):1238-1249.
Gangappa SN, Berriri S and Kumar SV, 2017. PIF4 coordinates thermosensory growth and immunity in Arabidopsis. Current Biology. 27(2):243-249.
Berriri S, Gangappa SN, Kumar SV, 2016. SWR1 Chromatin-Remodeling Complex Subunits and H2A.Z Have Non-overlapping Functions in Immunity and Gene Regulation in Arabidopsis. Molecular Plant. 9(7):1051-65.
Yu N, Nützmann HW, MacDonald JT, Moore B, Field B, Berriri S, Trick M, Rosser SJ, Kumar SV, Freemont PS, Osbourn A., 2016. Delineation of metabolic gene clusters in plant genomes by chromatin signatures. Nucleic Acid Research. 8. Doi: 10.1093/nar/gkw100.
Berriri S, Garcia AV, Frei dit Frey N, Rozhon W, Pateyron S, Leonhardt N, Montillet JL, Leung J, Hirt H, Colcombet, 2012. Constitutively active mitogen-activated protein kinase versions reveal functions of Arabidopsis MPK4 in pathogen defense signalling. Plant Cell. 24(10):4281-93.