RT - Journal Article T1 - P5CS and PDH expression levels and proline content in rapeseed doubled haploid lines (Brassica napus) under salinity stress JF - MGJ YR - 2021 JO - MGJ VO - 16 IS - 1 UR - http://mg.genetics.ir/article-1-1632-en.html SP - 33 EP - 41 K1 - Gene expression K1 - Prolin dehydrogenase K1 - P5CS K1 - Salt stress K1 - Canola AB - Salinity is considered as one of the abiotic stresses, which decreases the agricultural production of most crops around the world. Plants use different of adaptive mechanisms to counteract the deleterious effects of salinity as changes in gene expression patterns and the content of compatible osmolytes such as proline. This study was conducted to investigate the effects of salinity stress on expression of P5CS and PDH genes and proline content in canola. To do this, a factorial experiment with three replications was carried out in greenhouse of Agricultural Sciences and Natural Resources of Khuzestan University. Three different lines of doubled haploids (Tolerant, Semi- Tolerant and Sensitive) and two sampling times were considered as the first and second factors. The plant seedling were exposed to 150 mM NaCl as salinity stress at 4-leaf stage. Then, the sampling was performed at 6 and 24 hours after stress application. The results of P5CS gene expression showed that this gene was expressed more in the sensitive line after 6 hours from NaCl application, its expression decreased after 24 hours from starting of stress. On the other hand, the gene expression of P5CS increased sharply in the tolerated line after 24 hours of stress. Comparison of the relative mean of PDH gene expression showed that the sensitive line had a significant increase at both times (6 and 24 hours after stress), while a semi-tolerant line had a significant decrease in PDH expression. The content of proline was more in tolerant line than the others, but non-significant difference observed between the semi-tolerant and sensitive lines in terms of proline content. The results of this study indicated that the expression of PDH and P5CR genes depends on the intensity of plant tolerance and post stress times. With considering the more gene expression in P5CS and greater inhibition of PDH activity in tolerant line, more proline accumulation was occurred in tolerant genotype rather than sensitive one. Therefore, proline may be used as an indicator osmolality in the identification of salt stress tolerance in canola. LA eng UL http://mg.genetics.ir/article-1-1632-en.html M3 ER -