Date of Award

1984

Publication Type

Doctoral Thesis

Degree Name

Ph.D.

Department

Biological Sciences

Keywords

Biology, General.

Rights

info:eu-repo/semantics/openAccess

Abstract

The chloroplast DNA from soybean (Glycine max L.) was isolated and characterized. Cleavage sites of restriction endonucleases KpNI, Pvu II, Sac I were arranged with respect to endonuclease Xho I sites by filter hybridization using Xho I fragments as labeled probes. A total of 66 sites were aligned on the soybean chloroplast genome. Restriction analysis indicates a circular DNA molecule of 151 Kb which is organized into two unequal single copy regions of 84 Kb (large) and 20 Kb (small). The large and small single copy regions are interrupted by a single 23.5 Kb repeat region on either side. The repeated region is organized in an inverted orientation. Position of rRNA genes was determined by hybridizing radio-labeled 16S and 23S rRNAs. Results indicate that rRNA encoding region is present once per segment of the inverted repeat, hence two copies are present per chloroplast genome. The entire genome was cloned in 4.36 Kb pBR322 qnd 2.5 Kb pDPL13. A set of seven Pvu II fragments and a set of eight Sac I fragments were inserted in pBR322 and PDPL13 vectors respectively. Fine mapping of the cloned fragments containing the rRNA cistron (rDNA) suggests the presence of a single copy of 16S and 23S rRNA genes per rDNA unit. The 16S and 23S sequences in each unit are separated by 2.3-3.0 Kb spacer. The direction of transcription is from 16S to 23S. The tRNA genes for leucine, (trnL1, trnL2, TrnL3), serine (trnS), phenylalanine (trnF) were located by Southern hybridization. Plastid protein encoding genes were mapped by hybridizing internal region of gene probes from other plants to soybean restriction digests. The genes for ribulose-1,5-bisphosphate (rbcL), alpha, beta and epsilon subunit of CF(,1) (atpA, atpB and atpE respectively), Subunit III (DCCD binding polypeptide) of CF(,0) of ATP synthase (atpH, the cytochrome f (CytF), and the "32Kd" polypeptide (psbA) are located in the large single copy region.Dept. of Biological Sciences. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis1984 .S476. Source: Dissertation Abstracts International, Volume: 45-04, Section: B, page: 1095. Thesis (Ph.D.)--University of Windsor (Canada), 1984.

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