• Scientist E
  • Joining Date in NABI: 14th Nov, 2011
  • 0172-5221124
  • pandeyak@nabi.res.in

Discipline and Specialization:

Plant Molecular Biology, Functional Genomics, Phytic acid biology in plants.

Training/advance exposure in the area of work:

1. Post Doctoral Research Fellow (Oct 2008-Oct 2011): Department of Plant Pathology, 351 Bessey Hall, Iowa State University, Ames, Iowa 50011, USA. (Physical Address): Foreign Disease-Weed Science Research Unit, USDA-ARS, Ft Detrick (Army Base), Frederick, Maryland, USA. Herein, we utilized virus induced gene silencing (VIGS) on resistant cultivars of soybean plants (Rpp1 and Rpp2) to decipher the defense pathways network against the rust disease caused by Phakopsora species.

2. Post Doctoral Fellow (Sep 2004-Oct 2008): Department of Biological Sciences, University of Alabama, Huntsville, AL-35899. USA. We studied the genetic determinants for the cold stress and its persistent pathogenicity in B. cinerea. Minor projects include development of functional genomics in ectomycorrhizal fungus Laccaria bicolor.

3. Post Doctoral Fellow (July 2003-Sept 2004): Institute of Plant and Microbial Biology, Academia Sinica, Taiwan. We focused on understanding the mechanisms of disease resistance manifested by transgenic HRAP Arabidospsis and the role of bacterial elicitor harpin.

Contribution to the scientific advancement

• Phytic acid (IP6) beside been a storage form of phosphorus in cereal grains is also a well know seed anti-nutrient. The chelating properties of PA in seeds contribute to reduced iron and other micronutrients bioavailability. In plants, the ability of phytic acid to chelate some important micronutrients including iron has led to the designing of the strategy to target the biosynthesis pathway of IP6 in different crops. The areas of the inositol phosphate and phytic acid biology in wheat remain largely elusive and unexplored. Our group identified wheat PA pathway genes and subsequently the gene function was validated using yeast mutants. In total, seven genes for wheat PA biosynthesis pathway were identified and subsequently their expression was studied in different tissues and in presence of exogenous hormones.

• In addition, we also raised wheat transgenic targeted for gene silencing of TaABCC13, that is a putative transporter of PA. Multiple lines of wheat transgenic were raised and were subjected to molecular and biochemical analysis. Lowering of PA (28-32%) in grains was achieved. Silenced wheat plants also showed phenotypic changes in the formation of lateral root and its sensitivity towards the heavy metal like cadmium.

• We are also deciphering the role of other transporter either involved in phosphate remobilization or translocation. In this direction, 23 wheat phosphate transporters (PHTs) were identified encompassing all the subfamily of these transporters. Subsequently, we have identified seed specific phosphate transporters and currently we are utilizing genome editing tools so as to control the flux of phosphate (substrate for PA) in cereal grains. We also demonstrated that phosphate and PA accumulation are linked at the molecular level in the developing grains of wheat.

Current area of research:

Project I: Metabolic engineering of phytic acid pathway for improving iron bioavailability in wheat:

The deficiency of micronutrients remains an enormous global problem in developing countries. Phytic acid (myo-inositol-1,2,3,4,5,6- hexakisphosphate; PA; InsP6) beside been a storage form of phosphorus in seed is also a well know seed anti-nutrient. The chelating properties of PA in seeds contribute to reduced iron and other micronutrients bioavailability. To improve the value of seed crops, considerable effort has been made in recent years with limited success to modify seed iron content via genetic engineering or by conventional breeding. One of my current research interest deals with the utilization of functional genomics tools to address the role of phytic acid synthesis pathway genes. The goal is to reduce the total PA content in wheat grains and therefore increasing bioavailability of iron. Role of higher forms of PA are also been explored in cereal grains in anticipation of its role in phosphate-PA homeostasis. We are utilizing genome editing based techniques to generate wheat germplasm resources for the specific trait.

Project II: Role of transporters involved in phosphate and iron homeostasis:

In an attempt to modulate the total PA content in seeds, new approaches are been explored. One of the ways to control the accumulation of PA is by targeting the transport of phosphorus (P) in the filial tissue i.e. developing grains. Identifying the specific role of phosphate transporters (PHT) and studying its impact on total seed P levels would be an important work to improve the efficient utilization of P supply. Although, the Pi uptake was predominantly studied by addressing role of PHT subfamily genes, but there are very limited studies indicating any role of such transporters for inorganic phosphate (Pi) remobilization in seeds. This work will address and identifies the tissue specific key molecular players involved for Pi loading in grains. Simultaneously, loading of iron will be explored by studying certain transporters that are involved in micro-nutrient remobilization. Interplay, between Fe- and Pi-transporter will also be explored in developing grains.