Lipid biosynthesis in seeds of mustard (Brassica juncea) influenced by zinc and sulphur deficiency

Abstract

S. 1990. Lipid biosynthesis in seeds of mustard {Brassica juncea) influenced by zinc and sulphur deficiency. -Physiol. Plant. 80: 102-108.In developing seeds of mustard {Brassica juncea L. cv. RLM198) the period between 20 and 30 days after fertilization (DAF) was identified as the period of active lipid biosynthesis, although dry matter continued to accumulate until maturity. The period of lipid synthesis was associated with a decrease in starch, soluble sugars and protein, thus, giving rise to precursors for the biosynthesis of lipids. Besides decreasing the dry matter content (on both % and seed basis), Zn and S deficiency caused a significant (F < 0.05) reduction in oil content. As compared to control, the decrease in oil content was 11, 12 and 18% at ,30 DAF and 4, 9 and 16% at maturity in Zn, S and (Zn+S) deficient treatments, respectively. Throughout the period of seed development, a significant decrease in starch anil protein with a slight accumulation of soluble sugars was observed due to deficiency of Zn or S. The rate of [l-'^Cj-acetate incorporation into total lipids, which was maximal at 30 DAF, also displayed a significant decrease due to the abovementioned mineral deficiencies. Addition of Zn or S in vitro, enhanced the lipid synthesis at all stages of seed development. Under Zn and S deficiency, the phospholipids increased from 10 to 30 DAF and then declined until maturity. However, the proportion of giycolipids and free fatty acids increased, with a corresponding decrease in total giycerides. Further, io deficiency treatments, there was an increase in 22:1 with a corresponding decrease in 18:1, 18:2 and 18:3 in developing and mature mustard seeds.

Distribution and biochemical composition of large and small seeds of soybean (Glycine max L.)

“…Samples were divided into three replicates, each with duplicate observations. Lipids were extracted by the method of Folch et al 16 The methods used for the estimation of soluble sugars, starch, lipid content, different lipid classes and fatty acid composition were as given in Munshi et al 17 The extraction and estimation of soluble proteins was done as per the method of Lowry et al 18 The storage proteins of the seeds were extracted and separated into glycinins and β-conglycinins by the method of Pant and Tulsiani 19 and electrophoretically separated by the method of Laemmeli. 20 The protein extract (250-300 µg) was processed with 6 mol L −1 urea and sodium dodecyl sulfate (SDS)-three volumes, 0.01% bromophenol blue and sucrose and 150 µg of protein was loaded in each well of the electrophoretic gel.…”

Sugar, Non-volatile and Phenolic Acids Composition of Strawberry Tree (Arbutus unedo L. var.ellipsoidea ) Fruits

“…Half of the extract (25 mL) was concentrated at 403C under diminished pressure. The aqueous extract obtained was de-proteinated with basic lead acetate, removing excess lead by addition of sodium oxalate crystals (Munshi et al, 1990). The sugar-free residue after ethanol extraction was air-dried, and used for GC-MS analysis.…”

Sugar and Phenolic Acid Composition of Stored Commercial Oleaster Fruits

“…The aqueous extract was de-proteinated with basic lead acetate and the excess lead was removed by the addition of sodium oxalate crystals. Then, the sample was again extracted with ethanol (70%) and the ethanolic extract was air dried and used for gas chromatographic analysis (Munshi et al, 1990).…”