Tropentag, September 19 - 21, 2012 in Göttingen "Resilience of agricultural systems against crises"

Differential Expression of alp Gene and Sporulation Pattern of Glomus with Ri T-DNA Transformed Hairy Roots

The Energy and Resources Institute, Biotechnology and Bioresources Division, India

Abstract

After nitrogen, phosphorous (P) is second most limiting element for plants growth. It is a major component of fundamental macromolecules, plays an important role in energy transfer, regulation of enzymatic reactions and different metabolic pathways. P is taken up by plant roots as phosphate (Pi), which is one of the least available nutrients in the soil even after application of P-fertilisers. Plants have evolved a variety of adaptive strategies for Pi-acquisition which involves altered root morphology, exudation of organic acids, phosphatases and nucleases for solubilising Pi from organic resources and the establishment of a symbiosis with arbuscular mycorrhizal fungi.
Alkaline Phosphatase gene (alp) is an AMF specific, considered to reflect fungal activity within the symbiotic system and not reported in uncolonised roots as it is expressed only under symbiotic conditions.

In this study the Ri T-DNA transformed roots were grown in vitro with Glomus intraradices as root organ cultures and analysed for the variations in patters for sporulation, alp gene expression and nutrient growth profiling. It was demonstrated that alp gene regulating the production of alkaline phosphatases was host dependent. For the nutrient analysis, the phosphorus concentrations obtained were similar to those obtained in the real time expression study with a maximum for Daucus carota var pusa kesar (carrot), followed by Trifolium subterraneum (egyptian clover), followed by Daucus carota var Berlicummer (carrot) with 0.9993 correlation factor.

This study helps in the selection of appropriate inoculum as a biofertiliser, based on its enzymatic ability to solubilise the phosphates and aiding better nutrient uptake in agricultural crops.

Keywords: Alp gene, biofertilisers, inocula, nutrient growth profiling, phosphorus, real time expression, sporulation

Contact Address: Alok Adholeya, The Energy and Resources Institute, Biotechnology and Bioresources Division, Darbari Seth Block, India Habitat Centre, Lodhi Road, 110003 New Delhi, India, e-mail: alokateri.res.in