osmotic stress; phosphoproteomics; guard cells; starch; circadian clock; b-amylase; ABA
Flütsch Sabrina, Nigro Arianna, Conci Franco, Fajkus Jiří, Thalmann Matthias, Trtílek Martin, Panzarová Klára, Santelia Diana (2020), Glucose uptake to guard cells via STP transporters provides carbon sources for stomatal opening and plant growth, in EMBO reports
, 21(8), e49719.
Abraham Paul E., Hurtado Castano Natalia, Cowan‐Turner Daniel, Barnes Jeremy, Poudel Suresh, Hettich Robert, Flütsch Sabrina, Santelia Diana, Borland Anne M. (2020), Peeling back the layers of crassulacean acid metabolism: functional differentiation between Kalanchoë fedtschenkoi epidermis and mesophyll proteomes, in The Plant Journal
, 103(2), 869-888.
Flütsch Sabrina, Wang Yizhou, Takemiya Atsushi, Vialet-Chabrand Silvere R. M., Klejchová Martina, Nigro Arianna, Hills Adrian, Lawson Tracy, Blatt Michael R., Santelia Diana (2020), Guard Cell Starch Degradation Yields Glucose for Rapid Stomatal Opening in Arabidopsis, in The Plant Cell
, 32(7), 2325-2344.
Thalmann Matthias, Coiro Mario, Meier Tiago, Wicker Thomas, Zeeman Samuel C., Santelia Diana (2019), The evolution of functional complexity within the β-amylase gene family in land plants, in BMC Evolutionary Biology
, 19(1), 66-66.
Moles Tommaso Michele, de Brito Francisco Rita, Mariotti Lorenzo, Pompeiano Antonio, Lupini Antonio, Incrocci Luca, Carmassi Giulia, Scartazza Andrea, Pistelli Laura, Guglielminetti Lorenzo, Pardossi Alberto, Sunseri Francesco, Hörtensteiner Stefan, Santelia Diana (2019), Salinity in Autumn-Winter Season and Fruit Quality of Tomato Landraces, in Frontiers in Plant Science
, 10, 1078.
Gurrieri Libero, Distefano Luca, Pirone Claudia, Horrer Daniel, Seung David, Zaffagnini Mirko, Rouhier Nicolas, Trost Paolo, Santelia Diana, Sparla Francesca (2019), The Thioredoxin-Regulated α-Amylase 3 of Arabidopsis thaliana Is a Target of S-Glutathionylation, in Frontiers in Plant Science
, 10, 933.
Flütsch Sabrina, Distefano Luca, Santelia Diana (2018), Quantification of Starch in Guard Cells of Arabidopsis thaliana, in BIO-PROTOCOL
, 8(13), e2920.
Starch is the most abundant form in which plants store carbohydrate. Starch serves functions that range over timescales from minutes to years, according to the cell-type from which it is derived. In guard cells, which border the stomatal pores that control water and carbon dioxide exchange with the environment, starch can be mobilized within minutes, helping to generate organic acid and sugars to increase guard cell turgor and promote stomatal opening. In the rest of the leaf, starch typically accumulates gradually during the day and is metabolized at night to support metabolism. Starch is intimately integrated with plant biology. Rearrangements of starch metabolism occur in response to changes in day length, light intensity, water deficit or extreme temperatures in a cell type-specific manner, such that carbon supply is ultimately optimized to sustain continued growth under changing environmental conditions. Such adaptive plasticity of starch metabolism is a key plant survival strategy. During phase I of this SNF project, we made a new fundamental discovery on how the ability of the plant to adjust starch turnover to the need of the individual cells depends upon sub-functionalization amongst the chloroplastic members of the Arabidopsis b-amylase (BAM) gene family. BAM is the main starch-degrading enzyme. We showed that BAM1 and BAM3 are active under different conditions and in a cell-type specific manner. We identified important upstream components affecting BAM activity, demonstrating that an intricate network of differential transcriptional and post-translational regulation underpins BAM isoform sub-functionalization. This ground breaking and exclusive findings present yet only the tip of the iceberg. Urgent research is needed to expand the frontiers in our knowledge on BAM isoform sub-functionalization and its impact on plant survival under changing environmental conditions. We propose pioneering innovative approaches, ranging from guard cell phosphoproteomics, high-resolution analytical imaging and in vivo radioisotope labelling of protein synthesis and turnover in a mix that is rather unique for my laboratory and will allow us to unravel the underlying molecular mechanisms of such a remarkable adaptive plasticity of starch metabolism in plants. Given that BAM are highly conserved in plants, our work will encourage further investigations on the influence of starch adaptive plasticity on plant survival in the environment in plants with commercial value. This ultimately will have broader implications for the generation of plants with high adaptation to extreme weather conditions, allowing extending the cultivation in fallow lands to ensure food security in the face of the expanding world’s population.