Headspace-Solid Phase Microextraction Approach for Dimethylsulfoniopropionate Quantification in Solanum lycopersicum Plants Subjected to Water Stress.
Dimethylsulfoniopropionate (DMSP) and dimethyl sulphide (DMS) are compounds found mainly in marine phytoplankton and in some halophytic plants. DMS is a globally important biogenic volatile in regulating of global sulfur cycle and planetary albedo, whereas DMSP is involved in the maintenance of plant-environment homeostasis. Plants emit minute amounts of DMS compared to marine phytoplankton and there is a need for hypersensitive analytic techniques to enable its quantification in plants. Solid Phase Micro Extraction from Head Space (HS-SPME) is a simple, rapid, solvent-free and cost-effective extraction mode, which can be easily hyphenated with GC-MS for the analysis of volatile organic compounds. Using tomato (Solanum lycopersicum) plants subjected to water stress as a model system, we standardized a sensitive and accurate protocol for detecting and quantifying DMSP pool sizes, and potential DMS emissions, in cryoextracted leaves. The method relies on the determination of DMS free and from DMSP pools before and after the alkaline hydrolysis via Headspace-Solid Phase Micro Extraction-Gas Chromatography-Mass Spectrometry (HS-SPME-GC-MS). We found a significant (2.5 time) increase of DMSP content in water-stressed leaves reflecting clear stress to the photosynthetic apparatus. We hypothesize that increased DMSP, and in turn DMS, in water-stressed leaves are produced by carbon sources other than direct photosynthesis, and function to protect plants either osmotically or as antioxidants. Finally, our results suggest that SPME is a powerful and suitable technique for the detection and quantification of biogenic gasses in trace amounts.
Trees and Timber Institute, National Research Council of ItalySesto Fiorentino, Italy; Department of Agriculture, Food and Environment, University of PisaPisa, Italy.
Stefano
S
Catola
Institute of Ecosystem Study, National Research Council of ItalySesto Fiorentino, Italy; School of Biology, Indian Institute of Science Education and ResearchThiruvananthapuram, India.
Srikanta Dani
SD
Kaidala Ganesha
Department of Agriculture, Food and Environmental Science, University of Florence Florence, Italy.
Luca
L
Calamai
Department of Biology, Agriculture and Food Sciences, National Research Council of Italy Roma, Italy.
Francesco
F
Loreto
Department of Agriculture, Food and Environment, University of Pisa Pisa, Italy.
Annamaria
A
Ranieri
Trees and Timber Institute, National Research Council of Italy Sesto Fiorentino, Italy.
Mauro
M
Centritto
analytical method; mass spectrometry; plant physiology; sampling; sulfur compounds