Expression of genetically distinct superoxide dismutases in the maize seedling during development

Baum, James A.; Scandalios, John G.

doi:10.1002/dvg.1020030103

Cited by 14 publications

(9 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Previous studies on the plastid and cytosolic isozymes of glyceraldehyde-3-phosphate dehydrogenase (17), superoxide dismutase (8), and elongation factor G (18) also showed antigenic differences. Additional three-way comparisons involving other cyanobacterial enzymes and isozyme pairs from plants are needed to test the generality of the PGI results.…”

Section: Discussionmentioning

confidence: 84%

“…Each compartment contains its own unique isozyme for most, ifnot all, ofthe reactions (1)(2)(3). Insofar as their genetic basis has been studied, the plastid isozymes were found to be coded by nuclear genes (4)(5)(6), these genes being distinct from those coding the cytosolic enzymes (3,7,8). The origin of these genes is an important yet poorly understood subject.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Immunological similarity between a cyanobacterial enzyme and a nuclear DNA-encoded plastid-specific isozyme from spinach

Weeden

Higgins

Gottlieb

1982

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

The immunochemical properties of the plastid and cytosolic isozymes of phosphoglucose isomerase (glucosephosphate isomerase; D-glucose-6-phosphate ketol-isomerase, EC 5.3.1.9) in spinach (Spinacia oleracea) and the single phosphoglucose isomerase enzyme from the cyanobacterium Synechococcus sp. were compared by an application of the enzyme-linked immunosorbent assay. Utilizing antibodies made in rabbits against subunits of purified plastid and cytosolic phosphoglucose isomerase isozymes from spinach, we demonstrate that the plastid isozyme is immunochemically more similar to the cyanobacterial enzyme than to the spinach cytosolic counterpart. The The reactions of glycolysis and the oxidative pentose phosphate pathway occur in both the plastids and the cytosol ofplant cells. Each compartment contains its own unique isozyme for most, ifnot all, ofthe reactions (1-3). Insofar as their genetic basis has been studied, the plastid isozymes were found to be coded by nuclear genes (4-6), these genes being distinct from those coding the cytosolic enzymes (3,7,8). The origin of these genes is an important yet poorly understood subject.The genes coding each pair ofplastid/cytosolic isozymes may have been formed as a result of an ancient duplication event in early plant eukaryotes. Gene duplication with subsequent divergence and specialization appears to be an important mechanism of isozyme formation (9). An alternative hypothesis (10) suggests that the genes coding the plastid isozymes may represent portions of the genome of a prokaryotic endosymbiont that were incorporated into the nuclear DNA during the evolution of the plant cell. According to this model, cytosolic isozymes are products of the original "host" genome. Additional mechanisms for the development of plastid isozymes can be postulated, but the two mentioned above appear to be the most viable.We attempted to distinguish between these two possible origins for the gene coding the subunits of the plastid-specific phosphoglucose isomerase (PGI; glucosephosphate isomerase; D-glucose-6-phosphate ketol-isomerase, EC 5.3.1.9) by using an immunochemical approach. The relative similarity ofthe two isozymes of PGI from several flowering plants and the single PGI enzyme present in the cyanobacterium Synechococcus sp. UTEX 625 were determined by an application of the relatively simple and sensitive enzyme-linked immunosorbent assay (ELISA). Our results indicate that the plastid-specific PGI is much more closely related to the cyanobacterial PGI than to the cytosolic isozyme.MATERIALS AND METHODS PGI Purification. Spinach plastid and cytosolic PGI were purified to homogeneity by a series of column chromatography steps (11). Synechococcus PGI was purified by the same procedure used for the plastid-specific isozyme. The plastid and cytosolic PGI from cauliflower (Brassica oleracea), sunflower (Helianthus annuus), and Clarkia xantiana (Onagraceae) were partially purified as described in ref. 11.Production of Antisera. The spinach PGIs were subjected to preparative p...

show abstract

Section: Discussionmentioning

confidence: 84%

mentioning

confidence: 99%

Immunological similarity between a cyanobacterial enzyme and a nuclear DNA-encoded plastid-specific isozyme from spinach

Weeden

Higgins

Gottlieb

1982

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

show abstract

“…The regulation of SOD expression has been studied most extensively in microorganisms (see [10,16]); there are, however, a few studies on the regulation of SOD genes in angiosperms, and of these the most detailed work has been done on the monocot maize [5,6]. The availability of cDNA clones encoding the two main isozymes in tomato allowed us to investigate SOD expression at the gene level during normal plant development, and under stress conditions.…”

Section: Discussionmentioning

confidence: 99%

The tomato Cu,Zn superoxide dismutase genes are developmentally regulated and respond to light and stress

1991

View full text Add to dashboard Cite

The expression of the two Cu,Zn superoxide dismutase (SOD) genes of tomato was followed in different organs and plant developmental stages at the transcript and enzymatic activity levels. The cDNA clones used as probes code for the chloroplast Cu,Zn SOD (clone T1) and the cytosolic Cu,Zn SOD (clone P31). The two genes were found to display distinct expression patterns. While the T1 transcript was rare or absent from roots, stems and ripening fruits, the P31 transcript was very abundant in these organs. Shoot tips, flower buds, seedlings and young leaves contained high levels of the two mRNAs. During leaf expansion, the levels of both transcripts diminish markedly. Despite the diminished presence of transcripts, SOD activity levels of the corresponding cytosolic and chloroplast isozymes accumulated and were sustained throughout leaf expansion. In non-photosynthetic organs, the SOD-3 (cytosolic) isozyme contained most of the activity, while in the expanded leaf the SOD-1 (chloroplast) isozyme was more abundant. Light-regulated accumulation of both the P31 transcript (1.7-fold) and the T1 transcript (3-fold) was observed upon light exposure of etiolated seedlings. However, only SOD-1 activity was observed to increase, after a lag of a few hours. The levels of both transcripts increased in response to paraquat and mechanical wounding. The level of the cytosolic transcript and the respective isozyme activity increased dramatically during prolonged drought stress while the chloroplast transcript remained unaffected. The expression of both genes was enhanced by spraying tomato plants with ethephon--a compound that releases ethylene. Our data show that the expression of Cu,Zn SOD genes in tomato is modulated in response to a variety of factors and suggest the importance of oxyradical toxicity as well as the role of SOD in the defence mechanism of plants exposed to stress.

show abstract

“…The genetic analysis, subcellular location, developmental expression, and biochemical properties of these isozymes have been studied in detail (1)(2)(3)(4). These SOD enzymes catalyze the dismutation of the superoxide anion to molecular oxygen and hydrogen peroxide (5).…”

mentioning

confidence: 99%

Cloning of cDNA for maize superoxide dismutase 2 (SOD2).

Cannon¹,

White²,

Scandalios³

1987

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

A cDNA clone encoding maize cytosolic superoxide dismutase 2 (SOD2) was isolated from a cDNA library constructed in pUC9 plasmids from size-selected poly(A)+ RNA. The library was screened with mixed synthetic oligodeoxynucleotide probes. The sequence of the probes was derived from the amino acid sequence from a region of the protein near the NH2 terminus. One positive clone contained an insertion of a 612-base-pair fragment. The amino acid sequence, deduced from the nucleotide sequence of the cDNA, revealed that the clone contained the coding region for all but the first of the 151 amino acids of the SOD2 protein. Additional 5' and 3' flanking sequences, absent on the pUC9 Sod2 clone, were obtained from a Xgtll clone isolated from a maize leaf library probed with the pUC9 Sod2 insert. Hybrid-selection translation assays also demonstrate that the cDNA clone contains Sod2 sequences.The nuclear-encoded metalloprotein superoxide dismutase (SOD; superoxide:superoxide oxidoreductase, EC 1.15.1.1) of maize consists of four isozymes: two cytosolic isozymes (SOD2, -4), a chloroplast-associated isozyme (SOD1), and a mitochondrial-associated isozyme (SOD3) (1). The genetic analysis, subcellular location, developmental expression, and biochemical properties of these isozymes have been studied in detail (1-4). These SOD enzymes catalyze the dismutation of the superoxide anion to molecular oxygen and hydrogen peroxide (5). In performing this reaction, these enzymes provide an important defense against oxygen toxicity in the various cellular compartments of maize (6-8).We report in this paper the isolation, DNA sequence, and amino acid sequence deduced from the cytoplasmic Sod2 cDNA clone. MATERIALS AND METHODSNH2-Terminal Sequence Analysis of SOD2 and -4. Maize SOD2 and -4 proteins were purified to homogeneity from 5-day-old scutellar tissue from the inbred maize line W64A as described (9). The sequence of the first 25 amino acids of the NH2 terminus of each protein was kindly provided by M. Hermodson (Purdue University).Preparation of Radioactive Oligonucleotide Probes. Mixed heptadecamers, corresponding to the amino acid sequence of the SOD2 protein, were synthesized by the solid-phase phosphite chemical method developed by Matteucci and Caruthers (10) (see Fig. 1). The chemically synthesized probe was labeled at the 5' end with [_'y32P]ATP (>7000 Ci/mmol; 1 Ci = 37 GBq; ICN) and T4 polynucleotide kinase (P.L.) by the method described (11). This procedure routinely yielded specific activities of =2 x 109 cpm/,g.RNA Isolation and Size Selection. Poly(A)+ RNA was isolated from frozen 5-day-old scutella by the sodium borate method (12). Briefly, the scutella are homogenized in sodium borate buffer, digested with proteinase K, and precipitated in LiCl. Poly(A)+ RNA was obtained from the total RNA by two sequential passages over an oligo(dT)-cellulose column (13). The poly(A)+ RNA was size-fractionated on methylmercury/agarose gels as described (14).Construction of cDNA Clones from Size-Selected mRNA. A cDNA library was ...

show abstract

Expression of genetically distinct superoxide dismutases in the maize seedling during development

Cited by 14 publications

References 27 publications

Immunological similarity between a cyanobacterial enzyme and a nuclear DNA-encoded plastid-specific isozyme from spinach

Immunological similarity between a cyanobacterial enzyme and a nuclear DNA-encoded plastid-specific isozyme from spinach

The tomato Cu,Zn superoxide dismutase genes are developmentally regulated and respond to light and stress

Cloning of cDNA for maize superoxide dismutase 2 (SOD2).

Contact Info

Product

Resources

About