Responses of <i>Salvinia</i> plant as possible bioindication to Al toxicity and its interaction with putrescine

Abstract

In the present experiment some of the cellular responses in relation to carbohydrate and nitrogen metabolites were analyzed under various concentration of Al salt along with polyamine application ( 0, 240, 360, 480 µM of Al salt [KAl (SO 4 ) 2 ,12H 2 O] and 480 µM of Al salt with 1 mM Put) . Plant responded well with some significant variation under Al concentrations when carbohydrate metabolism was studied both as reserve carbohydrate as well as from enzymatic aspects. Thus, a significant decline in total carbohydrates in whole plant including reducing sugars was the feature for Salvinia plants under Al concentration. On the contrary, the metabolism of sugars were monitored in terms of invertase and sucrose phosphate synthase activity in-vitro those recorded an up regulatory trend. This was modulated by putrescine. Photosynthetic efficiencies were measured indirectly with the assay of malate dehydrogenase and phosphoenol pyruvate carboxylseactivities and recorded to be up regulated. For the nitrogen metabolizing attributes enzymes like nitrate reductase, glutamine-2-oxoglutarate amino-transferaseand glutamine synthase recorded a diminishing trend all through Al concentration. On the contrary, glutamate dehydrogenase recorded an up-regulated trend. Therefore, nitrogen metabolism is modified with Al toxicity proportionately and thereby could be used as possible bioindicator under similar condition for Salvinia plants. With this background the present paper has discussed some aspects of carbohydrate and nitrogen metabolism in Salvinia under Al toxicity. More so, the role of polyamine has also deciphered in alleviation of Al stress with interaction of those metabolites. Abbreviations PA: Polyamine; Put: Putrescine; DNS: di-nitro salicylic acid; DTT: dithiothrietol; EDTA: Ethylene diamine tetra acetic acid; PMSF: Phenyl-methyl-sulfonyl-fluoride; MOPS: 3-(N-morpholino) propanesulfonic acid; PEP: phospho enol pyruvate; PVP: polyvinyl pyrrolidone; PVPP: poly-vinyl-poly-pyrrolidone; SPS: sucrose phosphate synthase; MDH: malate dehydrogenase activity; PEPC: Phosphoenol pyruvate carboxylase; NR: nitrate reductase; GDH: glutamate dehydrogenase; GOGAT: glutamine-2-oxoglutarate aminotransferase; GS: glutamine synthase