Expression profiling of PAP3, BZIP, and P5CS genes in soybean underdrought stress conditions

Authors: VALIOLLAH SOLEIMANI, JAFAR AHMADI, SABER GOLKARI, BEHZAD SADEGHZADEH

Abstract: Under drought stress, a signaling system induces the expression of specific genes to alleviate the harmful effects of drought stress. The BZIP gene is a transcription factor in the signaling abiotic stresses and plays a role in the regulation of responses to different stresses in plants. The P5CS gene controls the activity of the proline-5-carboxylate synthase enzyme that is involved in proline synthesis in drought stress conditions. In this research, the effect of drought stress was investigated on the expression of GmPAP3, GmBZIP and GmP5CS genes in two soybean cultivars, Williams (tolerant) and L17 (susceptible). Total RNA was isolated from leaves and roots of both nonstressed and stressed plants, and then cDNA was synthesized and used for real-time PCR. The housekeeping gene 18SrRNA was used to normalize data. Data analysis showed that the expression of GmPAP3, GmBZIP, and GmP5CS genes increased under drought stress. GmPAP3 and GmBZIP expressions were two-fold while GmP5CS expression was seven-fold greater in Williams than in L17. GmPAP3 and GmP5CS gene expressions were similar in leaves and roots, while GmBZIP expression was higher in roots than in leaves. In conclusion, the increased expression of these genes could be attributed to higher drought tolerance in cultivar Williams and it seems that transferring these genes into susceptible cultivars may enhance drought tolerance in soybean.

Keywords: GmPAP3, GmBZIP, GmP5CS, Glycine max, water stress

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