scholarly journals Lipoxygenase and Its Relationship with Ethylene During Ripening of Genetically Modified Tomato (Solanum lycopersicum)

2020 ◽  
Vol 58 (2) ◽  
pp. 223-229
Author(s):  
Arturo Alberto Velázquez-López ◽  
Javier De La Cruz-Medina ◽  
Elizabeth León-García ◽  
Cristóbal Torres-Palacios ◽  
Gilber Vela-Gutiérrez ◽  
...  

Research background. TomloxB is the main isoform of lipoxygenase associated with ripening and senescence of fruits. On the other hand, ethylene, a gaseous hormone, is essential for the regulation of ripening in climacteric fruits like tomatoes. However, the relationship between TomloxB and ethylene production has not been thoroughly studied. Therefore, we aim to assess the effect of exogenous ethylene in transgenic tomatoes that contain a silenced TomloxB gene, and subsequently evaluate lipoxygenase activity, 1-aminocyclopropane-1-carboxylic acid oxidase and ethylene production; as well as to quantify the expression of the genes encoding 1-aminocyclopropane-1-carboxylic acid oxidase and TomloxB.Experimental approach. To investigate the effect of lipoxygenase and 1-aminocyclopropane-1-carboxylic acid oxidase activity, fruits harvested at the stages of break, turning and pink were used. Tomatoes at break stage collected from transgenic and wild type plants were used to determine ethylene production and gene expression. Genetically modified and wild type tomato fruits were exposed to 100 μL/L exogenous ethylene. Lipoxygenase activity was measured spectrophotometrically. Activity of 1-aminocyclopropane-1-carboxylic acid oxidase and ethylene production were determined by gas chromatography. Oligonucleotides for differentially expressed genes: 1-aminocyclopropane-1-carboxylic acid oxidase and TomloxB were used to determine gene expression by real-time PCR.Results and conclusions. The data showed that silencing of TomloxB caused a reduction in lipoxygenase activity and ethylene production in tomato fruits, and also reduced 1-aminocyclopropane-1-carboxylic acid oxidase activity. Hence, the addition of exogenous ethylene increased lipoxygenase activity in all treatments and 1-aminocyclopropane-1-carboxylic acid oxidase activity only in transgenic lines at break stage, consequently there was a positive regulation between TomloxB and ethylene, as increasing the amount of ethylene increased the activity of lipoxygenase. The results suggest that lipoxygenase may be a regulator of 1-aminocyclopropane-1-carboxylic acid oxidase and production of ethylene at break stage.Novelty and scientific contribution. These results lead to a better understanding of the metabolic contribution of TomloxB in fruit ripening and how it is linked to the senescence-related process, which can lead to a longer shelf life of fruits. Understanding this relationship between lipoxygenase and ethylene can be useful for better post-harvest handling of tomatoes.

1999 ◽  
Vol 26 (2) ◽  
pp. 179 ◽  
Author(s):  
Maria X. Henzi ◽  
David L. McNeil ◽  
Mary C. Christey ◽  
Ross E. Lill

In this paper 11 transgenic broccoli (Brassica oleracea L. var. italica) lines containing a tomato antisense 1-aminocyclopropane-1-carboxylic acid (ACC) oxidase gene from pTOM13 were evaluated. Changes in respiration, ethylene production and ACC oxidase activity were studied in mature flowers. Averaged across all ACC oxidase transgenic lines, there was an initial increase followed by a substantial decrease in ethylene production compared with the controls. Of the 11 transgenic lines, 10 lines showed a significant reduction in fethylene production relative to the controls from 50 h after harvest. Green Beauty flowers showed a significant reduction in respiration between the transgenics and control and demonstrated how ethylene levels could control the stable, or climacteric-like increase in respiration. ACC oxidase activity was higher in transgenic plants, consistent with the initially higher ethylene production. ACC oxidase activity did not, however, reflect the increase in ethylene production found after 50 h for the controls. These results suggest that two ethylene production systems may operate with only the second being inhibited by the antisense ACC oxidase used and that the later system was not detected by the ACC oxidase assay used. The results do show that post-harvest ethylene synthesis and therefore possibly broccoli senescence can be regulated by using an antisense ACC oxidase gene.


1999 ◽  
Vol 5 (3) ◽  
pp. 223-228 ◽  
Author(s):  
C. Larrigaudiere ◽  
I. Recasens ◽  
J. Graell ◽  
M. Vendrell

Changes in 1-aminocyclopropane-1-carboxylic acid metabolism in apples ( Malus domestica Borkh cv Granny Smith) were studied in relation to cold storage. Emphasis was given to the differential re sponsiveness of fruits to cold treatment as a function of stage of maturity at harvest. Fruits were held at 1 or 20 °C for 30 days, respectively, or exposed to 1 °C for 10 days and then storaged at 20 °C for up to 30 days. Fruits at 20 °C showed typical climacteric behavior. Differences at 1 °C between maturity stages in ethylene production and ACC oxidase activity were abolished, which showed that cold treatment is an important inducer of climacteric rise in preclimacteric Granny Smith apples. At 1 °C, ethylene production was lower than at 20 °C and the maxima in production were similar for all the stages of maturity, but took place at different times which corresponded exactly to the initial differ ences in harvest dates. After the transfer to 20 °C, fruits exhibited similar behavior as regards ethyl ene production, ACC oxidase activity, and ACC and MACC levels in relation to a harmonization process which is discussed in this study.


2003 ◽  
Vol 128 (3) ◽  
pp. 309-315 ◽  
Author(s):  
Jacqueline K. Burns ◽  
Luis V. Pozo ◽  
Covadonga R. Arias ◽  
Brandon Hockema ◽  
Vidhya Rangaswamy ◽  
...  

Coronatine is a polyketide phytotoxin produced by several plant pathogenic Pseudomonas spp. The effect of coronatine on abscission in Citrus sinensis L. Osbeck `Hamlin' and `Valencia' orange fruit, leaves, fruitlets, and flowers was determined. Coronatine at 200 mg·L-1 significantly reduced fruit detachment force of mature fruit, and did not cause fruitlet or flower loss in `Valencia'. Cumulative leaf loss was 18% with coronatine treatment. Coronafacic acid or coronamic acid, precursors to coronatine in Pseudomonas syringae, did not cause mature fruit abscission. Ethylene production in mature fruit and leaves was stimulated by coronatine treatment, and 1-aminocyclopropane-1-carboxylic acid oxidase (ACO) and 12-oxo-phytodienoate reductase (12-oxo-PDAR) gene expression was upregulated. A slight chlorosis developed in the canopy of whole trees sprayed with coronatine, and chlorophyll content was reduced relative to adjuvant-treated controls. Leaves formed after coronatine application were not chlorotic and had chlorophyll contents similar to controls. Comparison of coronatine to the abscission compounds methyl jasmonate, 5-chloro-3-methyl-4-nitro-pyrazole and ethephon indicated differences in ethylene production and ACO and 12-oxo-PDAR gene expression between treatments. Leaf loss, chlorophyll reduction and low coronatine yield during fermentation must be overcome for coronatine to be seriously considered as an abscission material for citrus.


HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 571d-571
Author(s):  
Jean-Claude Pech

We have generated transgenic Cantaloupe Charentais melons expressing an ACC oxidase antisense gene in which ethylene production was reduced to less than 1% as compared to control untransformed fruits. As a consequence, some aspects of the ripening process were strongly inhibited (aroma volatiles production, chlorophyll and cell wall degradation, pigmentation of the rind, activation of peduncular abscission zone) while others remained unchanged (coloration of the flesh), allowing us to distinguish between ethylene-dependent and ethylene-independent pathways. Some postharvest characteristics of the transgenic fruit are described in terms of expression of ripening-related genes, respiratory behavior, and biochemical composition. Data also are presented showing that exogenous ethylene treatments could reverse the antisense phenotype.


Genetics ◽  
1983 ◽  
Vol 103 (2) ◽  
pp. 277-285 ◽  
Author(s):  
Ryuichi Konno ◽  
Yosihiro Yasumura

ABSTRACT d-Amino acid oxidase activity in the kidney homogenates of mice of seven strains was measured to search for a mutant for this enzyme. There was a consistent sex difference in the enzyme activity in these strains: male mice showed higher levels of the enzyme activity than females. In contrast to other strains, some mice of the ddY strain did not possess enzyme activity. This trait was inheritable, and a mouse stock without enzyme activity (DAO-) was established. The allele (Dao-1c) carried by the DAO- mice was recessive and behaved as a single autosomal gene in inheritance. Heterozygous mice for this gene (Dao-1  +/Dao-1c) showed nearly half the enzyme activity of the wild-type homozygotes (Dao-1  +/Dao-1  +), suggesting that Dao-1c is a null allele and that there is a gene dosage effect on the enzyme activity.


2019 ◽  
Vol 11 (37) ◽  
pp. 34053-34058
Author(s):  
Marzena Fandzloch ◽  
Carmen R. Maldonado ◽  
Jorge A. R. Navarro ◽  
Elisa Barea

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