Expression pattern of key gene(s) of GA biosynthesis and Brassinosteroid pathway influences in germination and growth-promoting in response to Ascophyllum nodosum extract

The yield and acceptable quality of the oil of canola make this plant as one of the most important plants for providing edible oil. Due to the hot and dry climate in Iran and water necessary for seed germination, discovery of the solution to improve germination and seedling establishment is required. Seed priming and treatment of seedlings with the extract of the seaweed Ascophyllum nodosum is one of the solutions for uniform germination and establishment of seedlings. The currently study have been explore the effect of application of Ascophyllum nodosum seaweed extract on seed germination and changes in the relative expression pattern of some important key genes related to gibberellic acid and brassinosteroids biosynthesis pathway using qRT-PCR. For this purpose, germination indexes were measured by the application of treatment 1% v/v treatment of Ascophyllum nodosum extract in four levels of treatment (0, 10, 15 and 30 days) until flowering stage. The leaf of sampling in each treatment was performed in three biological replications. The results of this study showed the effectiveness of seaweed extract treatment on increasing germination and seed vigor percentage, so that 100% germination of treated seeds obtained on the 3-day. The relative expression of algae extract showed an increase in the expression of EXP, ATI, ENTKO, AEC and BINSP genes, which are all important and as the key genes in the germination process compared to the control treatment. The use of seaweed extract treatment showed the highest expression in ATI (4.39) and ENTKO (5.70) genes in 30-day treatment, respectively. The lowest expressions for GIB and EXP genes in all three treatments (10, 15 and 30 days) were obtained. Also, there was the highest positive correlation between EEN and GIB (1), ENTKO and BINSP (0.98), AEC and BINSP (0.96) genes at the 5% significantly level. The correlation of these genes due to the use of algae extract ultimately led to a positive effect on the germination process of rapeseed seeds. Also, the results of heat map showed the genes of EXP and AEC (-0.57), GIB and ATI (-0.50) genes and XEN and ATI (-0.49) have a negative correlation at an error level of 5% and the increase of one led to the decrease of the other. This indicates that’s the activity of the final product of each of these genes is able to affect the germination process and promoting plant growth and development.