Transcriptional profiling and functional characterization of candidate genes related to iron enrichment in wheat Triticum aestivum L grains

Abstract

The microarray based comparative transcriptional profiling of developing grains of two wheat genotypes (IITR26 and WL711) for contrasting grain mineral content, several genes were identified as having differential expression. Predominance of transcripts related to mineral accumulation and transport, mineral tolerance, amino acid and protein transporters, lignin and flavonoid biosynthesis pathways, aquaporins, biotic and abiotic stress response were observed in IITR26 during grain filling stages. Probe sets related to lipid transport and binding (LTP family protein), mineral detoxification and sufficiency, reduction-oxidation, were up-regulated in WL711, during grain filling. Thus, the differential expression analysis of microarray data identified several candidate genes which may facilitate the elevated levels of minerals in the grains. newlineThe expression of TaVIT2D is similar to the pattern of iron accumulation in roots, stem, leaves, flag leaf and seeds of field grown wheat plants at 14 DAA of IITR26. TaVID2D responded to both Fe depletion and excess conditions. The investigation demonstrated that the over-expression of TaVIT2D in vit1 mutant of Arabidopsis improved its chlorophyll content, vegetative and reproductive growth. The complementation lines exhibited higher Fe and Mn content in roots, leaves and seeds under iron deficient conditions. Expression of genes involved in metal uptake and transport, FIT, FRO2 and IRT1, as well as NAS1, NAS2, YSL, and NRAMP was higher in the complementation lines as compared to Col-0 and vit1 mutant plants. Thus, TaVIT2D seems to be a promising candidate for biofortification of wheat, and the engineered plants may grow better in Fe deficient soils. newline newline