Expression analysis of some genes involved in lignin biosynthesis pathway under salt strees in soybean (Glycine max)

Background and Aim: Identification of co-expression genes that are effective in tolerating salinity stress in plants and evaluation of their expression in biochemical pathways can increase productivity and development of crop cultivation area.Methods: To investigate the effect of salinity treatment (۲۰۰ mM NaCl) on the expression level of some key genes of the lignin biosynthesis pathway, including CCR and COMT and their co-expression genes (CECCR and CECOMT) and a gene related to Soybean salinity (GmSALT۳), Real-Time polymerase chain reaction (PCR) was used at two intervals three and seven days after treatment in two salinity resistant and susceptible cultivars.Results: According to the laboratory results, the expression level of COMT gene in the resistant cultivar was increase ۲.۲۶ times compared to the control after ۳ days of salinity treatment and also it was significantly decrease ۴ times compared to the control in the susceptible cultivar after ۷ days of treatment. Also, the expression level of CECOMT gene in the studied samples showed a significant decrease (۱.۲ and ۳.۹۵ times compared to the control) in the resistant cultivar at three and seven days after treatment, respectively. On the other hand, CCR gene expression increased ۲۰۶.۵ times compared to the control in the resistant cultivar and seven days after treatment, which was significant at ۵% probability level. Also in the same cultivar, the expression level of CECCR co-expression gene at two intervals three and seven days after treatment was significantly decreased ۲۷.۰۲ and ۲۰۰ and ۱.۷۸ and ۲.۴۲ times compared to the control in the susceptible cultivar, respectively. The relative expression of GmSALT۳ gene was significantly increased in resistant cultivar ۲.۷۱ and ۱.۶۲ and ۷.۲۳ and ۱۵.۸۳ times compared to the control, respectively at intervals three and seven days after treatment.Conclusion: According to the results of this study, salinity treatment had a significant effect on the expression of genes involved in the lignin biosynthesis pathway, and its co-expression genes and salinity-tolerant genes in Soybean at intervals three and seven days.

Keywords:

Soybean , Salinity , Lignin , Co-expression genes