Relevance of the cellular pathway in Beta VULGARIS

VITALI V; BELLATI J; SOTO G; AYUB ND; AMODEO G

Congreso; ASPB; 2013

ASPB

Plant tolerance to abiotic stress is a subject that still includes unraveled features, especially in terms of water homeostasis and the regulatory mechanisms that water pathways might trigger to facilitate the tolerance. In salt stress, while ion transporters and/or channels have been described as crucial elements for achieving adjustments; the role of aquaporins and the contribution of the cell to cell pathway still remain unclear. In this study we examine the response of hydroponically grown Beta vulgaris plants submitted to salt stress (200 mM NaCl) during different time intervals (4, 8, 24 and 48 h). KCl was used as an alternative treatment in order to dissect the effect of the monovalent cation. Three-week-old Beta vulgaris plants show tolerance properties as recorded by their rapid turgid recovery (less than 48h) even for those that were exposed to longer stress periods (24-48h). The response was analyzed for each condition by means of different parameters as relative water content (RWC), growth rate, transpiration, as well as leaf water potential. All these physiological parameters were reduced in both treatments independently of the length of the submitted stress and did not allow us to dissect both ions. At the root level we observed a decrease in the transcript levels of three mainly expressed aquaporins, and also determined root hydraulic conductivity (Lpr). Interestingly, Lpr shows different patterns in terms of the source of stress -K+ or Na+- , in particular when plants where restored to control conditions. Therefore our results suggest that the root cellular pathway is also a crucial trait of the physiological mechanism and signals involved in the tolerance response.