Peroxidase activity and relative mobility at anthesis in flax genotrophs and their F2 progeny: developmental and genetic effects

Genome ◽  
1991 ◽  
Vol 34 (4) ◽  
pp. 495-504 ◽  
Author(s):  
M. A. Fieldes ◽  
J. Ross

The genetic regulation of the environmentally induced heritable difference in peroxidase activity between Durrant's large (L) and small (S) flax genotrophs was examined in leaves from plants ranging in developmental age from 6 days before anthesis to 3 days after. Mean peroxidase activity was higher for S than L and intermediate for the reciprocal F2's from L × S and S × L crosses (F2L × S and F2S × L). However, activity increased with development and, since there were small but significant differences in the average developmental ages of L, S, F2L × S, and F2S × L plants, the effects of development on activity had to be taken into account in examining the F2 activity data for segregation. A regression method was used to remove developmental effects and, underlying these effects, total peroxidase activity appeared to be regulated by a single locus with two alleles and L dominance. Two other dimorphic loci, both described previously, were also examined. One regulates the presence-absence of septa hairs in the seed capsules and the other the relative mobility of anionic peroxidase isozymes. There was no phenotypic linkage between the three segregating parameters. The genetic control of activity appeared to regulate cationic rather than anionic activity. In addition, a relationship between activity and plant height indicated either that peroxidase activity is one of the factors regulating main stem elongation or that the locus regulating peroxidase activity is linked to one of the loci involved in the regulation of plant height.Key words: flax genotrophs, peroxidase, genetic control, development.

1980 ◽  
Vol 22 (4) ◽  
pp. 529-534 ◽  
Author(s):  
H. Tyson ◽  
M. A. Fieldes

Anionic peroxidase isozymes from main stem tissues of adult plants of two flax (Linum usitatissimum L.) genotrophs were separated using acrylamide gel electrophoresis. A range of seven acrylamide concentrations was used for the gels, enabling the effect of gel concentration on relative mobility (Rm) to be examined. The regression of log (Rm) on gel concentration was linear for two of the four main isozymes found. Differences in linear regression slope between the L and S flax genotroph isozymes suggested genotroph differences in molecular weight.


1991 ◽  
Vol 69 (10) ◽  
pp. 2192-2196 ◽  
Author(s):  
R. Bronner ◽  
E. Westphal ◽  
F. Dreger

Peroxidase activity and its electrophoretic pattern were studied in resistant Solanum dulcamara leaves following infestation by the gall mite Aceria cladophthirus. Total peroxidase activity increased in infested leaves and was related to enhancement of three major peroxidase isozymes. The highest activity was found for the intercellular peroxidases. The extraction procedures used suggest that these peroxidases are pathogenesis-related proteins. These results are discussed with reference to the lack of lignin barrier around the mite-induced necrotic local lesions. Key words: Aceria cladophthirus, gall mite, Solanum dulcamara, resistant plant, pathogenesis-related proteins, peroxidases isozymes.


1977 ◽  
Vol 55 (11) ◽  
pp. 1465-1473 ◽  
Author(s):  
M. A. Fieldes ◽  
C. L. Deal ◽  
H. Tyson

Four peroxidase (EC 1.11.1.7) isozymes were isolated from each of two flax genotrophs. All four isozymes were glycoproteins and all exhibited indoleacetic acid (IAA) oxidase activity. The percentage purity of two of the isozymes was very high; these isozymes differed in percentage carbohydrate and in peroxidase and IAA oxidase specific activities. Three of the isozymes displayed molecular weight values of about 43 000; for the fourth, molecular weight was considerably higher. Corresponding isozymes from the genotrophs and from two other flax genotypes displayed molecular weight differences which corresponded to electrophoretic relative mobility differences. Enzyme yield per unit fresh weight was higher for one genotroph than the other, and the balance between peroxidase activity and IAA oxidase activity between the genotrophs was different.


2008 ◽  
Vol 133 (3) ◽  
pp. 315-319 ◽  
Author(s):  
Tao Wu ◽  
Jiashu Cao

Comparisons of total peroxidase activity and peroxidase isozymes as well as protein profiles among segregating, near-isogenic bush and vine phenotypes of pumpkin (Cucurbita moschata Duchesne) were investigated. Peroxidase activities of internode and leaf tissues of the bush plants were higher than those of respective vine tissues. Roots of bush plants, however, had a lower peroxidase activity than vine plants. In both bush and vine plants, peroxidase activities were lower in leaf tissues than in root and internode tissues. Electrophoretic comparisons revealed qualitative differences in peroxidase patterns in internodes between bush and vine plants. Moreover, qualitative differences between internode and root profiles were found between bush and vine plants in C. moschata. In conclusion, the results of this report revealed that a single gene conferring the bush phenotype in C. moschata might affect the relative expression of peroxidase activity, peroxidase isozymes, and protein profiles in leaf, internode, and root tissues.


HortScience ◽  
1995 ◽  
Vol 30 (3) ◽  
pp. 434c-434
Author(s):  
J.K. Collins ◽  
C. Biles ◽  
E.V. Wann ◽  
P. Perkins-Veazie

Increased peroxidase activity is used to predict development of off-flavor in frozen sweet corn. However, peroxidase activity was not indicative of flavor changes in frozen supersweet (sh2) or sugar enhanced (sul/se) sweet corn genotypes. These results suggested an inactivation or absence of certain peroxidase isozymes. Frozen `Florida Staysweet' (sh2), `Merit' (sul), and `Bodacious' (sul/se) kernels were cut from cobs after 0 and 12 months of storage. Proteins extracted from acetone powders were separated by isoelectric focusing (IEF) and Native-PAGE. Banding patterns differed according to cultivar and storage duration. All cultivars contained a peroxidase isozyme having a molecular weight of 99 kD and pI of 4.5. The sul/se and su2 cultivars expressed an additional peroxidase band of 17.9 kD. An additional peroxidase isozyme (pI 5.0) appeared after 12 months of storage in the sul cultivar. This isozyme did not appear in sul/se or sh2 and is a possible marker for predicting off-flavor in corn. This isozyme may also catalyze off-flavor reactions in sul corn genotypes. Although changes in total peroxidase activity may not predict flavor loss in all genotypes, certain peroxidase isozymes may be useful in predicting and catalyzing off-flavor reactions in sul corn cultivars.


2012 ◽  
Vol 40 (1) ◽  
pp. 243 ◽  
Author(s):  
S. Filiz GUCLU ◽  
Fatma KOYUNCU

This study was carried out on 1-year old trees of ‘0900 Ziraat’ variety grafted onto ‘Kuş kirazi’, ‘Kara idris’, ‘Sari idris’, ‘MaxMa 14’, ‘MaxMa 60’ and ‘Gisela 5’ in order to determine their compatibility. For this purpose, total peroxidase activity was determined by spectrophotomery assay. Taking ground tissue samples were planned three times as before the grafting (beginning), and then 8 and 12 months after grafting. Total peroxidase activities of rootstocks before grafting varied between 10.80 ΔAg.min. (‘Kuş kirazi’) and 7.83 ΔAg.min. (‘Kara idris’) and were found to be statistically important. The peroxidase activity of ‘0900 Ziraat’ was 11.07ΔAg.min. and the closest value occurred in Prunus avium rootstock. The most different values occurred in rootstocks of ‘Kara idris’ and ‘Gisela 5’. The results showed that peroxidase activity increased in rootstock and graft scion. This increase had higher values in heterogenetic combinations especially in ‘0900 Ziraat’/‘Gisela 5’ and ‘0900 Ziraat’/‘Kara idris’ grafts. Peroxidase activity was decreased at the 12th month for all combinations. The highest value was obtained from ‘0900 Ziraat’/‘MaxMa 14’ combinaion with 29.17 ΔAg.min. while lowest one was ‘0900 Ziraat’/‘Kuş kirazi’ with 17.39. The findings showed that peroxidase activity could be used as a parameter in early determination of graft incompatibility.


2017 ◽  
Vol 106 (3) ◽  
pp. 283-291 ◽  
Author(s):  
Sasha R. Howard ◽  
Leo Dunkel

The genetic control of puberty remains an important but mostly unanswered question. Late pubertal timing affects over 2% of adolescents and is associated with adverse health outcomes including short stature, reduced bone mineral density, and compromised psychosocial health. Self-limited delayed puberty (DP) is a highly heritable trait, which often segregates in an autosomal dominant pattern; however, its neuroendocrine pathophysiology and genetic regulation remain unclear. Some insights into the genetic mutations that lead to familial DP have come from sequencing genes known to cause gonadotropin-releasing hormone (GnRH) deficiency, most recently via next-generation sequencing, and others from large-scale genome-wide association studies in the general population. Investigation of the genetic control of DP is complicated by the fact that this trait is not rare and that the phenotype is likely to represent a final common pathway, with a variety of different pathogenic mechanisms affecting the release of the puberty “brake.” These include abnormalities of GnRH neuronal development and function, GnRH receptor and luteinizing hormone/follicle-stimulating hormone abnormalities, metabolic and energy homeostatic derangements, and transcriptional regulation of the hypothalamic-pituitary-gonadal axis. Thus, genetic control of pubertal timing can range from early fetal life via development of the GnRH network to those factors directly influencing the puberty brake during mid-childhood.


1982 ◽  
Vol 24 (4) ◽  
pp. 417-425 ◽  
Author(s):  
Mary Ann Fieldes ◽  
Hugh Tyson ◽  
David Marriott

Protein profiles of partially purified protein extracts from main stem tissue of Durrant's L and S flax (Linum usitatissimum L.) genotrophs were examined with one and two dimensional electrophoresis on acrylamide gels. The purification retained mainly glycoproteins. Among this reduced spectrum of plant proteins, some of the proteins separated had relative mobility (Rm) shifts between L and S. For two proteins, the Rm shifts were demonstrated in two-dimensional separations using mixtures of the L and S extracts. The Rm shifts were all in the same direction, the S protein ran slightly slower than the corresponding L protein, in both dimensions. This shift direction agreed with previous studies on Rm shifts with peroxidase and esterase isozymes and with similar shifts in acid phosphatase isozymes.


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