Evaluation of Chlorophyll Content and Genes Expression (Catalase and DREB1) in Soybean Cultivars Under Drought Stress Condition

Drought stress is one of the important factors that restrict crop production in tropical and semi-tropical areas. This experiment has taken place in Golestan province Agriculture research station in split plot format with RCBD design with four replicates. Drought stress as a main factor included three levels (irrigation after 50، 100، and 150 millimeters evaporation from the A class evaporation pot) of which 50 millimeters evaporation is considered as control. The sub factor included factorial combination of 3 varieties (DPX، Sari and WE6) and three sampling stages (flowering، packing pod and grain filling). Evaluated traits included A and B chlorophyll amount and alternation in gene expression. The amount of chlorophyll was increased on first step of the stress condition (100 ml evaporation) and decreased again، on the second step (150 ml evaporation). The TBARM level was increased under the stress condition as well as growth stages. The gene expression analysis was carried out by using QRT-PCR technique. The results showed at first level of drought stress condition catalase gene expression had the most amounts. It was quite similar to DREB1 gene expression. DPX variety showed the most DREB1 gene expression first level of drought stress condition in packing pod stage، and least reduction in second level of the drought stress condition. Sari variety showed the most reduction in DREB1 gene expression in second level of the drought stress condition. Chlorophyll amount also showed a positive correlation with the catalase and DREB1 genes expression.