The Effect of Iron Deficiency on the Relative Expression of Genes Encoding Transcription Factors bZIP56, WRKY1 and NAM-B1 in Bread Wheat (Triticum aestivum L.)

Bread wheat is one of the most important nutritional products throughout the world. Wheat, like other crops, faces many environmental constraints during the growing season, such as iron deficiency in the soil. Iron is one of the essential micronutrients in plants that act as a catalytic cofactor in several key processes including photosynthesis and respiration.

to investigate the expression pattern of genes encoding transcription factors WRKY1, bZIP56 and NAM-B1 under soil Fe deficiancy, a factorial experiment was conducted in a completely randomized design (CRD) with three replications. Pishtaz (Fe-efficient) and Falat (Fe–inefficient) bread wheat cultivars were planted under Fe deficiency (less than 1.5) and adequacy (5 mg Fe / kg soil) conditions and the relative expression of genes was measured in roots and leaves of the plants at vegetative (one month after germination) and reproductive (30% of heading) stages using real time PCR technique.

the results revealed the considerable enhanced expression of WRKY1 in the roots of Fe-efficient (Pishtaz) and -inefficient (Falat) cultivars at vegetative stage. The highest increased expression of bZIP56 and NAM-B1 genes was observed in the leaves and roots of Fe-efficient cultivar (Pishtaz) at vegetative and reproductive stage, respectively. The bZIP56 expression was also considerably enhanced in the leaves of Fe-inefficient cultivar in both stages.

Due to the increased relative expression of WRKY1 gene in leaves and roots of both cultivars at vegetative stage, this gene is likely involved in activating and inducing the expression of genes participating in iron uptake and transport in the early stages of plant growth. Also, the increased relative expression of bZIP56 gene in the roots of both cultivars in the reproductive stage indicates that this gene might be participated in activating the transcription of genes involved in iron absorption from the soil at the end of plant growth stages.