[Effect of salinity in free proline and betaine contents in Hyoscyamus aureus plants]

ABSTRACT

Hyoscyamus aureus plants were stressed with three different degrees of salinity in order to study relationships between inorganic ion contents and the contents of betaine and proline, both molecules being considered as plant osmoprotectives. Our results demonstrated that the greater the dry weight average and the [Na[+] + K[+] content and the lower the [Na[+] / Ca2[+] ratio, the higher the proline contents in leaves and roots. Proline accumulation is considered as a response to water deficit and a response against not only Na[+] ions but also K[+] ions accumulation and Ca[2+] ions protector effect. Betaine contents in leaves and roots were not only Na[+] concentration dependent but also depended on macronutrient ionic concentration, and this response showed up with certain lag. We can conclude from our results that in Hyoscyamus aureus plants, betaine accumulation is not a reliable parameter to detect salinity stress, but free proline content increases according to the salinity conditions