Investigating the effect of chitosan on gene expression, p5cs enzyme activity and proline content in rapeseed (Brassica napus L.) under salt stress

Salinity is one of the most important stresses that reduce the yield of most plants. Plants use different mechanisms in response to environmental stresses. Chitosan and its oligomers are used in plants to resist abiotic stresses such as salinity. In this study, the effect of chitosan and salinity on gene expression and p5cs enzyme activity and proline content in rapeseed was investigated.

For this purpose, rapeseed plants were treated with sodium chloride solution (0, 50, 100 and 150 mM) and chitosan (0, 5 and 10 mg/l). The experiment was performed as a factorial experiment with a completely randomized design in 3 replications. Treated plants were harvested to measure gene expression, p5cs enzyme activity and proline content.

With increasing salt concentration, the expression of delta-1 proline-5 carboxylate synthetase (P5CS) gene, enzyme activity and proline content increased. In the combined salinity of 100 mM with chitosan 10 mg/l, gene expression, activity and proline content in rapeseed had the highest amount. The use of chitosan in salt-containing medium compared to salinity treatments in same concentration, caused more P5CS gene to be expressed, increased enzyme activity and subsequently more proline was synthesized. Therefore, there is a positive correlation between gene expression, enzyme activity and the amount of proline produced.

According to the results, chitosan with a concentration of 10 mg / l in salinity treatment, by increasing gene expression and the activity of the enzyme delta-1-proline-5-carboxylate synthetase (P5CS), produced proline, which increases the plant's resistance to salinity stress.