Robustness of central carbohydrate metabolism in developing maize kernels.

The central carbohydrate metabolism provides the precursors for the syntheses of various storage products in seeds. While the underlying biochemical map is well established, little is known about the organization and flexibility of carbohydrate metabolic fluxes in the face of changing biosynthetic demands or other perturbations. This question was addressed in developing kernels of maize (Zea mays L.

Changes in flux pattern of the central carbohydrate metabolism during kernel development in maize.

Developing kernels of the inbred maize line W22 were grown in sterile culture and supplied with a mixture of [U-13C6]glucose and unlabeled glucose during three consecutive intervals (11-18, 18-25, or 25-32 days after pollination) within the linear phase of starch formation. At the end of each labeling period, glucose was prepared from starch and analyzed by 13C isotope ratio mass spectrometry and high-resolution (13)C NMR spectroscopy. The abundances of individual glucose isotopologs were calculated by computational deconvolution of the NMR data.

Biosynthesis of benzofuran derivatives in root cultures of Tagetes patula via phenylalanine and 1-deoxy-D-xylulose 5-phosphate.

Root cultures of Tagetes patula L. cv. Carmen were grown with a mixture of unlabeled glucose and [U-(13)C(6)]glucose or [1-(13)C(1)]glucose as carbon source.

GLC and GLC-mS analysis of thiophene derivatives in plants and in in vitro cultures of Tagetes patula L. (Asteraceae).

The occurrence of thiophenic compounds in diverse plant organs and in in vitro root-, callus- and cell suspension cultures of Tagetes patula cv. Carmen was investigated using capillary GLC and GLC-MS. The separation of thiophenes by capillary GLC and the group specific MS fragmentation with the typical sulfur isotope peaks allowed the unequivocal assignment of individual thiophenes in complex mixtures, even when occurring in traces and in the presence of different geometrical isomers.

Biosynthesis of thiophenes in Tagetes patula.

The biosynthesis of 5-(3-buten-1-ynyl)-2,2'-bithiophene was studied in root cultures of Tagetes patula. Organ cultures were grown with [U-13C(6)]glucose or [1-13C]glucose. The bithiopene and amino acids from cell protein were isolated and analysed by quantitative NMR spectroscopy.