Synthesis of DNA and the Development of Amylase and Phosphatase Activities in Cotyledons of Germinating Seeds of<i>Vaccaria pyramidata</i>

Bernhardt, D.; Trutwig, A.; Barkhold, A.

doi:10.1093/jxb/44.4.695

Cited by 8 publications

(2 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This amplification of the DNA content in the cell nucleus, known as endoreduplication, is important for the expression of some enzyme activities in some species. The inhibition of nuclear DNA synthesis by hydroxyurea suppresses the expression of hydrolytic enzyme activities in germinating cotyledons of Vaccaria pyramidata (Bernhardt et al 1993). The amplification of the DNA content in individual mitochondria may be related to the complex genome of plant mitochondria Fujie et al 1993 a).…”

Section: Discussionmentioning

confidence: 99%

Behavior of organelles and their nucleoids in the shoot apical meristem during leaf development in Arabidopsis thaliana L.

Fujie

Kuroiwa

Kawano

et al. 1994

Planta

View full text Add to dashboard Cite

Abstract. The behavior of organelle nucleoids and cell nuclei was studied in the shoot apical meristem and developing first foliage leaves of Arabidopsis thaliana. Samples were embedded in Technovit 7100 resin, cut into thin sections and stained with 4'-6-diamidino-2-phenylindole to observe DNA. Fluorimetry was performed using a video-intensified microscope photon-counting system. The DNA content of individual mitochondria was more than 1 Mbp in the shoot apical meristem and the young leaf primordium, and decreased to approximately 170 kbp in the mature foliage leaf. In contrast, the DNA content of individual plastids was low in the shoot apical meristem and increased until day 7 after sowing. Application of 5-bromo-2'-deoxyuridine, an analogue of thymidine, was usesd to investigate DNA synthesis in situ. The activities of DNA synthesis in the mitochondria and plastids changed according to the stage of development. Mitochondrial DNA was actively synthesized in the shoot apical meristem and young leaf primordia. This strongly suggests that the amount of mitochondrial DNA per mitochondrion, which has been synthesized in the shoot apical meristem and young leaf primordium, is gradually reduced due to continual divisions of the mitochondria during low levels of mitochondrial DNA synthesis. Synthesis of DNA in the plastid became active in the leaf primordia following DNA synthesis in the mitochondria, and the small plastids were filled with large plastid nucleotids. This enlargement of the plastid nucleoids occurred before the synthesis of ribulose-l,5-bisphosphate carboxylase/oxygenase and the development of thylakoids.Abbreviations: BrdU=5-bromo-2'-deoxyuridine; DAPI=4'-6-diamidino-2-phenylindole; DiOC 6 = 3,3'-dihexyloxacarbocyanine; mtDNA=mitochondrial DNA; mt-nucleoid=mitochondrial nucleoid; ptDNA = plastid DNA; pt-nucleoid = plastid nucleoid; Rubisco = ribulose-l,5-bisphosphate carboxylase/oxygenase Correspondence to: M. Fuije; FAX: 81(3)38141408; Tel.: 81(3)38122111, Ext. 4471

show abstract

Section: Discussionmentioning

confidence: 99%

Behavior of organelles and their nucleoids in the shoot apical meristem during leaf development in Arabidopsis thaliana L.

Fujie

Kuroiwa

Kawano

et al. 1994

Planta

View full text Add to dashboard Cite

show abstract

“…During the germination process numerous enzymes such as lipases, proteinases, phosphatases, hydrolyases, calmodulin, carboxypeptidases, and others (Mayer and Poljakoff-Mayber 1989;Bernier and Ballance 1993;Bewley and Black 1985;Bernhardt et al 1993;Cocucci and Negrini 1991;Washio and Ishikawa 1992) are either activated or de novo synthesized by one of the processes previously mentioned. Each of these enzymes are involved in the germination process and evidence now suggests that the synthesis or activation of some of these enzymes are regulated by plant growth substances.…”

Section: Imbibition Of Watermentioning

confidence: 99%