Physiological and Gene Expression Analysis of Calcium Silicate Supplemented-tomato under Salt Stress

Abstract

Presently, many countries have problems about plant salt stress due to drought and deposition of sea salt in agricultural land. Salt stress negatively affects plant growth and production. In this research, CaSiO₃ was applied to tomato plants growing under salt stress at 50 mM NaCl. The results showed that adding 1.25 mM CaSiO₃ can provide the higher chlorophyll contents, relative water contents and weight compared with those grown without 1.25 mM CaSiO₃. Gene expression of HAK5, APPR2-like gene and SOS2 were analyzed from tomato leaves under salt stress at 50 mM NaCl with and without 1.25 mM CaSiO₃. It was found that 1.25 mM CaSiO₃–treated plants under salt stress had the level of HAK5 expression were significantly higher than those plants without 1.25 mM CaSiO₃ in the fourth week. Moreover, the 1.25 mM CaSiO₃–treated plants also had the level of APPR2-like gene expression were significantly higher than those plants without 1.25 mM CaSiO₃ in the the second week. On the other hand, the expression levels of SOS2 cannot be detected in salt stress plants supplemented with and without 1.25 mM CaSiO₃ in the whole period. According to the experimental results, 1.25 mM CaSiO₃–supplemented salinity plant had physiological and salt–responed gene expression more potential than those without 1.25 mM CaSiO₃. Also, the 1.25 mM CaSiO₃–supplemented salinity plant tends to have physiological indices and gene expression most similar to the control plants until the fourth week.