Showing papers on "Sterculia foetida published in 2002"

Carbocyclic fatty acids in plants: Biochemical and molecular genetic characterization of cyclopropane fatty acid synthesis of Sterculia foetida

Abstract: Fatty acids containing three-member carbocyclic rings are found in bacteria and plants. Bacteria synthesize cyclopropane fatty acids (CPA-FAs) only by the addition of a methylene group from S-adenosylmethionine to the cis-double bond of monoenoic phospholipid-bound fatty acids. In plants CPA-FAs are usually minor components with cyclopropene fatty acids (CPE-FAs) more abundant. Sterculia foetida seed oil contains 65–78% CPE-FAs, principally sterculic acid. To address carbocyclic fatty acid synthesis in plants, a cDNA library was constructed from developing seeds during the period of maximum oil deposition. About 0.4% of 5,300 expressed sequence tags were derived from one gene, which shared similarities to the bacterial CPA-FA synthase. However, the predicted protein is twice as large as the bacterial homolog and represents a fusion of an FAD-containing oxidase at the N terminus and a methyltransferase at the C terminus. Functional analysis of the isolated full-length cDNA was conducted in tobacco suspension cells where its expression resulted in the accumulation of up to 6.2% dihydrosterculate of total fatty acids. In addition, the dihydrosterculate was specifically labeled by [methyl-14C]methionine and by [14C]oleic acid in the transgenic tobacco cells. In in vitro assay of S. foetida seed extracts, S-adenosylmethionine served as a methylene donor for the synthesis of dihydrosterculate from oleate. Dihydrosterculate accumulated largely in phosphatidylcholine in both systems. Together, a CPA-FA synthase was identified from S. foetida, and the pathway in higher plants that produce carbocyclic fatty acids was defined as by transfer of C1 units, most likely from S-adenosylmethionine to oleate.

Shoot Regeneration from Hypocotyl and Shoot Tip Explants of Sterculia foetida L. Derived from Seedlings

Abstract: Hypocotyl and shoot tip explants derived from the seedlings of Sterculia foetida were placed on MS medium supplemented with various cytokinin and auxin combinations. Cytokinin-like N^6-benzylaminopurine (BAP), kinetin (KN), thidiazuron (TDZ) and auxin-like indole acetic acid (IAA), naphthalene acetic acid (NAA) and indole butyric acid (IBA) were supplemented either individually or in combinations. The regenerated shoots were separated and placed on the rooting medium augmented with different auxin-like IAA, IBA and NAA (0.1-2 mgL^(-1)). IAA (2 mgL^(-1)) induced 3-4 roots from the cut end of the micro shoots. Rooted plantlets were acclimatized to field conditions by placing them in pots containing sterilized sand, soil and manure mixture (1:1:1) and subsequently transferred to field with 40% survival.