biologia plantarum

Biologia plantarum 41:287-292, 1998 | DOI: 10.1023/A:1001895420374

Fluoride-induced alteration of carbon and nitrogen metabolism in developing wheat grains

B. Asthir¹, A.S. Basra², S.K. Batta¹

¹ Department of Biochemistry, Punjab Agricultural University, Ludhiana -, India

² Department of Botany, Punjab Agricultural University, Ludhiana -, India

Effect of fluoride (10 and 50 mM) on the activities of sucrose metabolizing enzymes, alkaline inorganic pyrophosphatase, and transaminases in relation to the accumulation of free sugars, starch, and soluble protein was studied in detached ears of wheat cultured in a liquid medium. Culturing for 5 d in the presence of fluoride reduced the amount of grain starch whereas contents of total free sugars, particularly sucrose, and soluble protein increased. Fluoride inhibited the activities of soluble acid and neutral invertases, as well as sucrose synthase acting in the cleavage direction. Uptake of uniformly labelled ¹⁴C-sucrose or fructose was also drastically reduced by fluoride. Glutamate-oxaloacetate transaminase (GOT) and glutamate-pyruvate transaminase (GPT) activities also increased with fluoride addition in correspondence with an increase in soluble protein. Apparently, the wheat grain responds to fluoride-mediated disruption of carbon metabolism by a compensatory effect on nitrogen metabolism.

Keywords: enzyme activities; liquid culturing; protein; starch; sugars; Triticum aestivum

Subjects: carbon metabolism, fluoride; Fok1 repetitive sequence; nitrogen metabolism, fluoride; PRINS-FISH technique, DNA sequences localization; 45S rRNA genes; saccharide metabolism, fluoride; Triticum aestivum; wheat, grain development, fluoride

Published: March 1, 1998  Show citation