Small heat shock proteins and the cold stress responde in tomato fruit

ESCOBAR MARIELA; RE MARTÍN; FERRARO GISELA; SILVANA B. BOGGIO; VALLE ESTELA

Montevideo

Congreso; Primer Conferencia de la Sección Sudamericana de Cell Stress International; 2014

Ripening is the late developmental phase of tomato (Solanum lycopersicum L) fruit that starts when the green fruit reaches the final size and is completed when the fruit is red. This process also occurs in mature green fruits that have been harvested. Shelf life, one of the most important agronomic traits for tomato, is lengthened by storing fruit at low temperature. Susceptible fruits suffer physiological disorders known as chilling injury. It has been reported that mitochondrial small heat shock proteins (MT-sHSP) were induced after cold storage of tomato fruits. The overall objective of this study was to evaluate the tolerance to chilling injury of tomato fruits from transgenic plants with increased and attenuated levels of MT-sHSP23.8using a fruit-specific promoter. The transgenic plants were analyzed in their phenotype, antioxidant response, MT-sHsp23.8 gene expression and sHSP protein levels. Transgenic and non-transformed plants were phenotypically similar under control conditions. After cold treatment, fruits of all transgenic lines showed no differences in the expression levels of MT-Hsp23.8 compared to non-transformed fruits, increased in catalase activity of all tomato lines and in the levels of sHSPs of mature green fruits from the overexpressing lines. Silenced fruits were more susceptible to chilling injury while overexpressing fruits were more tolerant to the cold treatment. Overall these data indicate that MT-sHSP23.8 is involved in the response of tomato fruit to cold stress, which could have implications for developing tomato cultivars tolerant to environmental stress.