ABSTRACT

Salinity inhibits growth and development of most plants. Inhibition of shoot and root development is the primary response to the stress. Growth, morphology, anatomy, and physiology of roots are aected by salinity. Changes in water and ion uptake by the roots, production of hormonal signals that communicate information to the shoot, and changes in patterns of expression might induce changes in plant development. Since root growth is usually less sensitive to salt stress than shoot growth, an increased root/shoot ratio is oen observed when plants are subjected to saline conditions (Cheeseman 1988; Cruz and Cuatreno 1990; Bernstein et al. 2004; Perica et al. 2008; Khayyat et al. 2009; Cécooli et al. 2011). Root growth of halophytes may be aected dierently (Flowers and Colmer 2008). e restriction of root growth by salinity, which reduces the soil volume that can be explored by the root and hence the availability and uptake of water and essential minerals, diminishes the supply of nutrients to the shoot which may contribute to growth reduction (Pitman 1984; Bernstein et al. 1995; Lazof and Bernstein 1998). e increase in root/shoot ratio reduces the demand for element supply to the shoot and thereby has a potential to increase the ability of the root to supply those elements and present an adaptive advantage (Cheeseman 1988). A potentially negative eect of such a change is the decreased capacity of the shoot to supply assimilates to the root and the growing tissues, which is likely to aect plant development and survival particularly under long-term salinization.