A Comparison of Tomato Fruit Chloroplast and Chromoplast DNAs as Analyzed with Restriction Endonucleases

Plastid DNA was isolated from the chloroplasts of tomato (Lycopersicon esculentum var Traveler 76) leaves and the chromoplasts of ripe tomato fruit. Comparisons of the two DNAs were made by restriction endonuclease analysis using PvuII, HpaI, and BglI. No differences in the electrophoretic banding patterns of the restricted plastid DNAs were detected, indicating that no major rearrangements, losses, or gains of plastid DNA accompany the transition from chloroplast to chromoplast.Central to the ripening process in tomato fruit is the transition of chloroplasts in the green fruit to chromoplasts in the ripe fruit.In this process the morphology and biochemical activities of the plastids are profoundly altered. The granal thylakoids characteristic of chloroplasts degenerate and carotenoid inclusions form (5,13). Chl is lost and photosynthetic activities cease, whereas synthesis of carotenoid pigments increases dramatically (12).Chloroplasts contain DNA which encodes proteins functional in photosynthesis and protein and RNA components of the plastid protein synthesis apparatus (2, 17). Other plastids also contain DNA, sometimes in quantities greater than chloroplasts of the same plant (15). However, the role of plastid DNA in the function of these organelles is not known.This study addresses the question of whether changes in the plastid DNA are involved in the transition from chloroplast to chromoplast. Plastid DNAs were isolated from the leaves and from the red-ripe fruit of tomato. These DNAs were digested with restriction enzymes PvuII, HpaI, and Bgl I, and the electrophoretic banding patterns of the fragments were compared. Any rearrangements or other changes in plastid DNA that occur during the plastid transition would alter the pattern of restriction endonuclease cleavage sites and be detected as a change in size of restriction fragments. In previous work, Iwatsuki et al. (6)

mentioning

confidence: 89%

Restriction Enzyme Analysis of Tomato Chloroplast and Chromoplast DNA

Hunt

Hardison²,

Boyer³

1986

“…From the available data it appears unlikely that chr genes will be found in the plasmid genome (2,3,7,8,11,12). Plant breeders, however, have identified a number of genes that are probably chr.…”

Section: Plant Materialsmentioning

confidence: 99%

“…In analyzing the molecular genetics of chromoplast development, it is useful to consider chr2 and we have undertaken a program for the isolation of members ofthe set. For reasons cited earlier (2), we have chosen to work with the bell pepper Capsicum annuum L.From the available data it appears unlikely that chr genes will be found in the plasmid genome (2,3,7,8,11,12). Plant breeders, however, have identified a number of genes that are probably chr.…”

mentioning

confidence: 99%

Synthesis of Two Chromoplast-Specific Proteins During Fruit Development in Capsicum annuum

Newman¹,

Hadjeb²,

Price³

1989

The time-course of accumulation of two membrane proteins during fruit ripening was examined by sodium dodecyl sulfatepolyacrylamide gel electrophoresis and western blots in tissue extracts of Capsicum annuum L., vars Emerald Giant, Albino, and DNAP VS-12. The proteins, named ChrA and ChrB, were previously shown to occur specifically in chromoplasts. Fruit development was divided into five stages based on changes in color. MATERIALS AND METHODS Plant MaterialFruits of Capsicum annuum L., vars Emerald Giant, Albino, and DNAP VS-12 were grown in the greenhouse. Fruits were harvested and the proteins extracted on the same day. In analyzing the molecular genetics of chromoplast development, it is useful to consider chr2 and we have undertaken a program for the isolation of members ofthe set. For reasons cited earlier (2), we have chosen to work with the bell pepper Capsicum annuum L.From the available data it appears unlikely that chr genes will be found in the plasmid genome (2,3,7,8,11,12). Plant breeders, however, have identified a number of genes that are probably chr. C. annuum has four Mendelian loci that affect chromoplast development in mature fruit (5) and two other loci that affect chromoplast development in immature fruits (10). Our strategy has been to isolate chromoplast-specific proteins and, through these, to isolate chr genes.We previously reported the specific accumulation of a 58-kD and a 35-kD protein in chromoplasts of C. annuum (4).

“…The transformation of etioplasts (proplastids) to chloroplasts upon illumination of dark-grown seedlings and that of chloroplasts to chromoplasts in fruit tissues, such as tomato and Capsicum spp., are well characterized examples of organelle differentiation (1, 3,6,7,19,20,26). Several investigators have reported that the restriction profiles of DNA isolated from the chromoplasts are identical with those of chloroplast DNA (6,8,9,24). Piechulla et al (15,16) have demonstrated that the levels of most of transcripts for both chloroplast-and nucleus-encoded photosynthesis-specific genes in chromoplasts are lowered in the development of fruits.…”

mentioning

confidence: 99%

DNA Methylation Occurred around Lowly Expressed Genes of Plastid DNA during Tomato Fruit Development

Ngernprasirtsiri

Kobayashi²,

Akazawa³

1988

We have analyzed DNA methylation of plastid DNA from fully ripened red fruits, green mature fruits, and green leaves of tomato (Lycopersicon escukntum var. Firstmore). Essentially identical restriction profiles were obtained between chromoplast and chloroplast DNAs by EcoRI digestion. BstNI/EcoRII and HpaII/MspI are pairs of isoschizomers that can discriminate between methylated and unmethylated DNAs. These endonucleases produced different restriction patterns of plastid DNAs from tomato fruits compared to tomato leaves. Moreover, we have found from Southern blots that methylation was not detected in DNA fragments containing certain genes that are actively expressed in chromoplasts, whereas DNA fragments bearing genes that are barely transcribed in chromoplasts are methylated.