Biotechnologie, Agronomie, Société et Environnement (Jan 2009)
Insight into the role of catalases in salt stress in potato (Solanum tuberosum L.)
Abstract
In order to investigate a possible link between catalase (CAT) activity and salinity tolerance, an in vitro and in vivo study of the behavior of transgenic lines of potato (cv. ‘Désirée’) under salt stress conditions was carried out. Three groups of transgenic lines and non transformed control (DWT) were used in this study: lines expressing a bacterial catalase gene and lines repressing catalase activity by either co-suppression or anti-sense strategies. Various concentrations of NaCl were tested: in vitro 0, 25, 50 and 75 mM and in vivo 25, 50 and 75 mM. The results of this work show that the genetic modification of CAT activity affects the multiplication rate of vitroplants, as well as vegetative and physiological growth parameters under salt stress conditions. At 25, 50 and 75 mM of NaCl, over-expression (line KatE16) and repression of CAT increased and reduced respectively the multiplication rate of vitroplants. Differences between the transgenic lines and the wild type were evident in tuber yield and leaf chlorophyll content. These parameters were significantly increased in CAT over-expressing and slightly decreased in SU3 line repressed in CAT under 25 mM of salt stress. A stability of the potential quantum yield (Fv/Fm) was observed in the lines over-expressing the CAT at 25, 50 and 75 mM of NaCl. The repression of CAT was associated with a decrease of Fv/Fm value at 50 mM of NaCl. These results show that catalases contribute to salinity tolerance mechanisms in potato.
