Skip to main content
ARS Home » Research » Publications at this Location » Publication #189032
Title: THE COMPLETE CHLOROPLAST GENOME SEQUENCE OF CITRUS SINENSIS (L.) OSBECK VAR 'RIDGE PINEAPPLE': ORGANIZATION AND PHYLOGENETIC RELATIONSHIPS TO OTHER ANGIOSPERMS

Author
item Bausher, Michael
item SINGH, D - UNIV. CENTRAL FLORIDA
item LEE, S-B - UNIV. CENTRAL FLORIDA
item JANSEN, R.K. - UNIV. OF TEXAS, AUSTIN
item DANIELL, H. - UNIV. CENTRAL FLORIDA

Submitted to: DNA Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/22/2006
Publication Date: N/A
Citation: N/A

Interpretive Summary: Little is know about the chloroplast genome of crop plants , yet this part of the plant cell is the primary energy gathering mechanism which allow plants to survive and produce all of the products necessary for development. Chloroplasts, like mitochondria, are unique in that these organelles possess their own genome and a full complement of transcriptional and translation machinery to express their genetic information. Besides photosynthesis the chloroplasts contain important metabolic activities take place within chloroplasts including the production of starch, certain amino acids and lipids, some of the colorful pigments in flowers, vitamins and several key aspects of sulfur and nitrogen metabolism. Having genetic information about the chloroplast opens our horizon to use the chloroplast apparatus for organelle tranformation. Chloroplast engineering offers a number of advantages over nuclear transformation, including high-level transgene expression, which can be used in consort with non-host resistance to produce for new and emerging diseases (like citrus canker) and insect problems using multi-gene engineering in single transformation event and transgene containment via maternal inheritance. This work is the first record of a complete chloroplast genome of Citrus With this information it is possible to explore and implement new plant improvement strategies which place emphasis on fruit quality and eliminate new pest problems with transgene strategies.

Technical Abstract: The complete nucleotide sequence of the chloroplast genome of Citrus sinensis (L.) Osbeck var ‘Ridge Pineapple’ is contained here. The genome is 160,614 bp long and includes a pair of inverted repeats of 26,136 bp separated by small and large single copy regions of 18,942 bp and 89,400 bp, respectively. Annotation revealed a total of 133 genes, 113 of which are unique while 20 genes are duplicated in inverted repeat regions. Among these, 89 genes, including nine genes duplicated in the inverted region, code for proteins. There are four rRNA genes and 30 distinct tRNAs, seven of which are duplicated in the inverted repeat regions. Seventeen genes contain introns, 15 with a single intron and two with 2 introns. The gene order is identical to the available genome sequences of the Solanaceae family. However, the infA gene is absent in the citrus chloroplast genome. Repeat analysis identified 34 direct and inverted repeats 30 bp or longer with a sequence identity ' 90%. Comparison of protein coding sequences with expressed sequence tags (ESTs) revealed six RNA edits, five of which resulted in nonsynonomous modification of PetL, psbH, ycf2 and ndhA amino acid sequence.. Phylogenetic analysis of the protein coding genes are being performed to assess the relationship of citrus to the 30 other sequenced angiosperm chloroplast genomes. Availability of the complete chloroplast genome sequence will greatly increase successful chloroplast genetic engineering of Citrus. This report is the first record of the entire Chloroplast of Citrus and the Rutucease family.