FranceCountry of destination:
Potato (Solanum tuberosum) is a strategic crop in terms of food security because of its high yields per cultivated hectare. Tubers are rich in starch and vitamin C, and their protein content, if referred to dry weight, is similar to that of cereals. Tubers serve as a means for vegetative propagation to the plant, and external signals for coming winter such as short day and cool temperatures promote formation of these organs in all cultivars. Studies using strict short-day (SD) Andigena potato genotypes identified a member of the Flowering Locus T (FT) gene family, StSP6A, as the mobile signal for tuberization. The StSP6A gene is specifically induced in the leaf vasculature and its expression in SD is controlled by the homolog of Arabidopsis thaliana CONSTANS (CO), StCOL1. Like AtCO, StCOL1 expression is regulated by the circadian clock and coincidence of high transcript levels with light allows StCOL1 protein stabilization. StCOL1 protein has been found to accumulate in Long Day (LD) and directly activate expression of an additional FT family member, StSP5G, with a tuberization repressive function. The expression patterns of StSP5G and StSP6A are antagonist and previous results led to propose that in LD, StSP5G inhibits StSP6A via the repression of a still unknown StSP6A activator. The objective of the proposal is to obtain a better understanding of the CO-FT pathway in potato with the identification of the putative StSP6A activator using a combination of functional genomic approaches with ChIP-seq and RNAseq analyses and genetic approaches with creation of mutants by CRIPR-Cas 9 strategy. Identification of a StSP6A activator will have a strong scientific impact by providing a better understanding of the photoperiodic control of tuber formation, in addition to an applied impact since high temperatures during the night negatively impact tuber yield by interfering with StSP6A expression.
I am a permanent junior research scientist at INRA in Bordeaux since September 2016. I work on the characterization of the genetic and molecular control of the balance between flowering and stolon production in strawberry. During my PhD on the genetic and molecular control of the continuous flowering trait in strawberry (UREF, INRA Bordeaux), I identified keys actors involved in flowering in strawberry. I continued on the molecular characterization of these actors during my first post-doc training (BFP, INRA Bordeaux). Afterwards, I integrated the Membrane Biogenesis lab (CNRS Bordeaux) for a second post-doc training on the molecular characterization of candidate proteins involved in plasmodesmata structuration. During my research experience, based on strawberry, A. thaliana and N. benthamiana models, I acquired a large panel of skills including plant physiology, microscopy, genetics, genomics and functional characterization of candidate genes. I am currently AgreenSkills fellow in Salome Prat lab in the National Center of Biotechnology (CNB) in Madrid on the characterization of the genetic pathway involved in the photoperiodic control of potato tuberization. This mobility gives me the unique opportunity to improve my knowledge on a close related thematic, to develop new skills and to establish new collaborations.
Nicolas W, Grison M, Trépout S, Gaston A, Fouché M, Cordelières F, Oparka K, Tilsner J, Brocard L, Bayer E, 2017. Architecture and permeability of post-cytokinesis plasmodesmata lacking cytoplasmic sleeves. Nature plant, 3: 17082. Doi:10.1038/nplants.2017.82.
Perrotte J, Guédon Y, Gaston A, Denoyes B., 2016. Identification of successive flowering phases highlights a new genetic control of the flowering pattern in strawberry. Journal of Experimental Botany, 67 (19): 5643-5655.
Perrotte J*, Gaston A*, Potier A, Petit A, Rothan C, Denoyes B, 2016. Narrowing down the single homeoelogous FaPFRU locus controlling flowering in the cultivated octoploid strawberry using a selective mapping strategy. Plant Biotechnology Journal, 14: 2176-2189. (*co-first authors)
Gaston A*, Perrotte J*, Lerceteau-Köhler E, RousseauGueutin M, Petit A, Hernould M, Rothan C, Denoyes B. 2013. PFRU, a single dominant locus regulates the balance between sexual and asexual plant reproduction in cultivated strawberry. Journal of Experimental Botany, 64(7): 1837-1848. (*co-first authors)
Iwata H*, Gaston A*, Remay A, Thouroude T, Jeauffre J, Kawamura K, Oyant LH, Araki T, Denoyes B, Foucher F., 2012. The TFL1 homologue KSN is a regulator of continuous flowering in rose and strawberry. Plant Journal, 69: 116-125. (*co-first authors)