Phenotypic evaluation and gene expression analysis of metal homeostasis genes in barnyard millet (Echinochloa frumentaceae) lines

Barnyard millet, a versatile and multi-purpose crop, is nutritionally superior to other major cereals and it is known for the efficient accumulation of metals, mainly Fe. To study the phenotypic variation in different barnyard millet lines for selecting desirable phenotype with varying metal accumulation, a pot culture experiment was conducted with nineteen barnyard millet lines and screened at seedling, vegetative, flowering and maturity stages. The experiments were laid out in a completely randomized design with three replications. Out of nineteen lines screened, the increased plant height, total dry matter production, total chlorophyll content and nitrate reductase activity, was observed in the variety MDU1 and the performance of ACM-16-5 was comparatively lower. The results showed that performance of MDU1 and ACM-16-5 was significantly varied. Since, barnyard millet is an active accumulator Fe, gene expression study was carried out to unveil the transporters that are involved in Fe and Zn uptake and translocation at seedling and vegetative growth stages of MDU1, with rice (ASD16) as control. Of all six genes studied, the expression of NAS1, NAS2 and YSL2 in leaf of MDU1 at seedling and vegetative stages was variably expressed when compared to ASD16 and this could pave the way for enhanced metal uptake and its utilization in plant growth and development.