Publication Date: 2014.
Differential scanning calorimetry (DSC) was employed to investigate the vitrification and annealing behaviors of the most commonly used plant vitrification solutions (PVS). These solutions are employed to protect plant tissues towards ice formation and freeze injury, and help to the vitrification of these tissues, by globally reducing the intracellular fluids mobility. Glass transition temperatures (Tg) and heat capacity increments (∆Cp) were determined for five solutions PVS1, PVS2, PVS2 mod, PVS3 and PVS3 mod, with different composition, and a range of cooling and warming rates was employed. Glass transitions showed clear and consistent temperature differences within vitrification solutions, which could be related to composition and water content. Roughly, two sets of TG values were obtained, those for PVS1 and 2, at -112 ºC and -114 ºC, respectively, and those for PSV3, at -90 ºC. The observed Tg and ∆Cp, unexpectedly, did not significantly change within a wide range of cooling rates (from 5 ºC min-1 to liquid nitrogen quenching) and warming rates (from 5 to 20 ºC). Garlic shoot tips cryopreserved after the droplet method produced a similar result to that of the vitrification solutions employed. After quench cooling to temperatures below Tg, repeated excursions to higher temperatures were made and the cooling and warming Tg were recorded. These treatments had little or no effect over the PVS solutions Tg, which remained practically constant. A direct practical consequence is that the plant vitrification solutions glass transition temperature does not significantly change with cryopreservation methods based on either direct plunging of samples into liquid nitrogen or employing closed cryovials.
Author affiliation: Schneider Teixeira, Aline. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico la Plata. Centro de Investigaciones En Criotecnología de Alimentos (i); Argentina. Universidad Nacional de La Plata; Argentina. Consejo Superior de Investigaciones Científicas. Instituto de Ciencia y Tecnologia de Alimentos y Nutrición; España
Author affiliation: Faltus, Milos. Crop Research Institute; República Checa
Author affiliation: Zámečníkc, JirI. Crop Research Institute; República Checa
Author affiliation: Gonzalez Benito, Maria Elena . Universidad Politécnica de Madrid. Escuela Técnica Superior de Ingenieros Agrónomos de Madrid; España
Author affiliation: Molina García, Antonio D. . Consejo Superior de Investigaciones Científicas. Instituto de Ciencia y Tecnologia de Alimentos y Nutrición; España
Repository: CONICET Digital (CONICET). Consejo Nacional de Investigaciones Científicas y Técnicas