scholarly journals 24-Epibrasinolide Modulates the Vase Life of Lisianthus Cut Flowers by Modulating ACC Oxidase Enzyme Activity and Physiological Responses

Plants ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 995
Author(s):  
Mohammad Darvish ◽  
Habib Shirzad ◽  
Mohammadreza Asghari ◽  
Parviz Noruzi ◽  
Abolfazl Alirezalu ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
Water Absorption ◽  
Ethylene Production ◽  
Oxidase Activity ◽  
Acc Oxidase ◽  
Postharvest Quality ◽  
Vase Life ◽  
Dependent Manner ◽  
Cut Flowers ◽  
Oxidase Enzyme

Ethylene is the most important factor playing roles in senescence and deterioration of harvested crops including cut flowers. Brassinosteroids (BRs), as natural phytohormones, have been reported to differently modulate ethylene production and related senescence processes in different crops. This study was carried out to determine the effects of different levels of 24-epibrassinolide (EBL) on ACC oxidase enzyme activity, the final enzyme in ethylene biosynthesis pathway, vase life, and senescence rate in lisianthus cut flowers. Harvested flowers were treated with EBL (at 0, 3, 6, and 9 µmol/L) and kept at 25 °C for 15 days. The ACC oxidase activity, water absorption, malondialdehyde (MDA) production and vase solution absorption rates, chlorophyll and anthocyanin contents, and the vase life of the flowers were evaluated during and at the end of storage. EBL at 3 µmol/L significantly (p ≤ 0.01) enhanced the flower vase life by decreasing the ACC oxidase activity, MDA production and senescence rates, and enhancing chlorophyll and anthocyanin biosynthesis and accumulation, relative water content, and vase solution absorption rates. By increasing the concentration, EBL negatively affected the flower vase life and postharvest quality probably via enhancing the ACC oxidase enzyme activity and subsequent ethylene production. EBL at 6 and 9 µmol/L and in a concentration dependent manner, enhanced the ACC oxidase activity and MDA production rate and decreased chlorophyll and anthocyanin accumulation and water absorption rate. The results indicate that the effects of brassinosteroids on ethylene production and physiology of lisianthus cut flowers is highly dose dependent.

scholarly journals 1-MCP and STS as ethylene inhibitors for prolonging the vase life of carnation and rose cut flowers

2004 ◽  
Vol 10 (4) ◽  
Author(s):  
F. Hassan ◽  
G. Schmidt ◽  
Y. M. Hafez ◽  
M. Pogány ◽  
J. Ankush
Keyword(s):  
Heavy Metal ◽  
Ethylene Production ◽  
Untreated Control ◽  
Postharvest Quality ◽  
Vase Life ◽  
Ethylene Inhibitors ◽  
Cut Flowers ◽  
Initial Weight ◽  
Silver Thiosulfate

The effect of STS and 1-MCP on the postharvest quality of carnation and rose cut flowers was studied. Cut flowers of Dianthus c..aryophyllus L. cv. Asso and Rosa hybritia cv. Baroness were treated with silver thiosulfate (STS) at 0.4 mM with sucrose at 50 g 1-t and 1-methylcyclopropene ( I -MCP) at 0.5 g m-3 for 611. Pretreatment with STS and 1-MCP significantly extended the vase life and minimized the % loss of initial weight of carnation and rose cut flowers comparing to the untreated control. The two chemicals applied inhibited the chlorophyll degradation and carbohydrate loss and hence, significantly improved the postharvest quality of carnation and rose cut flowers comparing to the control. Ethylene production by cut flowers was inhibited as a result of using these chemicals. In general, there were no differences between STS and (-MCP but the later does not have the heavy metal implications of STS treatment, and hence, using 1-MCP pretreatment for extending the vase life of carnation and rose cut flowers was recommended.

scholarly journals Genetic Transformation of Dendrobium 'Sonia Earsakul' with Antisense Carica papaya ACO1 Gene

2015 ◽  
Vol 9 (12) ◽  
pp. 125 ◽  
Author(s):  
Piyanuch Sornchai ◽  
Sermsiri Chanprame
Keyword(s):  
Enzyme Activity ◽  
Southern Blot ◽  
Ethylene Production ◽  
Blot Hybridization ◽  
Acc Oxidase ◽  
Southern Blot Hybridization ◽  
Plant Genome ◽  
Vase Life ◽  
Dot Blot ◽  
Transgenic Lines

<p><em>Dendrobium</em> orchid is one of the major export cut flowers not only in Thailand but also for several tropical countries. However, the production of ethylene by their flowers causes a shorter vase life. Flowers that contained lower levels of ethylene usually exhibited delayed senescence and consequently prolonged vase life. The transfer of antisense <em>ACC oxidase (ACO)</em> gene into orchid, in theory, may leads to decreased ethylene production because this gene can down regulates the ethylene biosynthesis pathway. This study focuses on the transformation and the existence and expression of the antisense <em>ACO</em>1 gene from papaya, namely (<em>CP-ACO</em>1), which was transferred in to <em>Dendrobium</em> 'Sonia Earsakul'. The successful stable transformation event obtained and the existence of the transferred gene was determined using PCR, dot blot hybridization and Southern blot hybridization techniques. The results revealed that antisense <em>CP-ACO</em>1 and <em>hygromycin phosphotransferase (hpt)</em> gene existed in all transgenic lines confirmed by PCR technique. The genomic dot blot confirmed the incorporation of the transgene in transgenic plant genome. Southern blot hybridization revealed the existed of one to four sets of the gene in transgenic lines. The expression of antisense <em>CP-ACO</em>1 gene was analyzed through the level of ACO enzyme activity and ethylene production in transgenic orchid. All of the transgenic lines had lower ACO enzyme activity and lower ethylene production than that of the non-transgenic orchid plants.<strong> </strong></p> <p> </p>

Cysteine Residues on Neutrophil p29 Peroxiredoxin Are Required for Enhanced Oxidase Activity.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 654-654
Author(s):  
Daniel R. Ambruso ◽  
Gail Thurman ◽  
Carolina Gonzalez-Aller
Keyword(s):  
Enzyme Activity ◽  
Plasma Membrane ◽  
Amino Acid ◽  
Recombinant Proteins ◽  
Respiratory Burst ◽  
Oxidase Activity ◽  
Cysteine Residues ◽  
Dependent Manner ◽  
Oxidase Enzyme ◽  
O2 Production

Abstract Introduction: Production of reactive oxygen species (ROS) through the respiratory burst is critical to the microbicidal activity of the neutrophil. The respiratory burst is initiated by assembly of an active NADPH oxidase enzyme system. This system has several components including gp91phox and p22phox comprising the membrane associated cytochrome b558 and the cytosolic components p47phox, p67phox, p40phox and rac2. Recently, we identified a novel protein with a molecular weight of 29 kDa which binds p67phox by immunoprecipitation and yeast two-hybrid analysis (Leavey et al J Biol Chem2002;277:45181–7). This protein is classified as peroxiredoxin (Prx) by its amino acid sequence and enzyme activity. Prxs oxidize H2O2 through conserved cysteines. The neutrophil p29 Prx has a cysteine at amino acid residue 47 flanked by a consensus sequence shared by other 1-cys Prx proteins and a second cysteine at residue 91. We have also shown that neutrophil p29 Prx translocates to the cell membrane during oxidase activation and enhances oxidase activity in a cell-free assay with recombinant phox cytosolic components and neutrophil plasma membrane. The current studies were undertaken to evaluate requirements of cysteine residue(s) for the effect on the oxidase. Methods: cDNA for p29 Prx was cloned into pBlueBacHis vector and a recombinant protein was expressed in a baculovirus expression system as previously described. Two additional recombinant proteins with ser substituted for cys at residue 47 and 91 were generated using the PCR overlap technique and also expressed in Sf9 cells. The wild type (WT), C47S, and C91S recombinant proteins were purified by affinity chromatography. The effect of these proteins on oxidase activity was determined in a SDS cell-free system of oxidase activity using plasma membrane (1 μg), p47phox (100 nM), p67phox (100 nM), a constitutively active Rac and 1 mM NADPH. O2− production was measured as SOD inhibitable cytochrome c reduction. Results: O2− Production (nmol/min) Concentration (μM) WT C47S C91S * Numbers are mean ± SEM, n=3 ** Significantly different from no addition, p<0.05 0 7.15 ± 0.46* 6.38 ± 0.81 7.11 ± 0.10 0.55 11.86 ± 1.33** 5.42 ± 0.73 6.57 ± 0.54 0.83 14.58 ± 2.09** 7.32 ± 1.02 7.29 ± 6.70 1.10 17.66 ± 2.50** 7.41 ± 1.19 7.64 ± 0.76 1.65 19.93 ± 2.82** 8.37 ± 1.37 8.14 ± 1.23 WT p29 Prx increased oxidase activity in a concentration dependent manner. Neither the C47S nor C91S mutants altered oxidase activity to a significant degree. Additional studies varying concentration of NADPH at several concentrations of p29 Prx demonstrated that p29 Prx increased the Vmax without changing the km for NADPH. At a fixed concentration of NADPH, the increase in rate of O2− generation was dependent upon p29 Prx concentration demonstrating saturable kinetics with a km for p29 Prx of 1.72 ± 0.65 μM and a Vmax (increase in velocity) of 15.4 ± 3.0 nmol/min (mean ± SEM for four separate studies). Conclusion: Neutrophil p29 Prx enhances oxidase enzyme activity. The enhancement is specific, exhibiting a saturable effect dependent on the concentration of p29 Prx. However, replacement of either conserved or non-conserved cysteine residues with serines resulted in an inactive protein. Cysteine residues which are required for Prx activity are also critical to the effects of neutrophil p29 Prx on the oxidase.

scholarly journals Senescence Symptoms after Emasculation Vary among Cymbidium Cultivars

HortScience ◽  
1998 ◽  
Vol 33 (4) ◽  
pp. 734-735 ◽  
Author(s):  
Jung Nam Suh ◽  
Kiyoshi Ohkawa ◽  
Beyoung Hwa Kwack
Keyword(s):  
Ethylene Production ◽  
Oxidase Activity ◽  
Acc Oxidase ◽  
Cultivar Differences ◽  
Vase Life ◽  
Fresh Weight ◽  
Before And After

Response of cut Cymbidium flowers to emasculation was investigated. All Cymbidium cultivars that we examined produced ethylene during senescence. There were marked cultivar differences in the changes of fresh weight, ethylene production, and lip coloration after emasculation. In the case of `Venus', flower emasculation did not alter fresh weight, ethylene production, or lip coloration. There were differences in ACC oxidase in vivo activity among the three cultivars before and after emasculation. There was a correlation between the initial ACC oxidase activity and time to lip coloration in the emasculated flowers, but not in control flowers. It was suggested that the initial ACC oxidase activity of the column may be related to flower response to emasculation rather than vase life during senescence.

scholarly journals Introgression of Sub1 (SUB1) QTL in mega rice cultivars increases ethylene production to the detriment of grain- filling under stagnant flooding

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Sandhya Rani Kuanar ◽  
Kutubuddin Ali Molla ◽  
Krishnendu Chattopadhyay ◽  
Ramani Kumar Sarkar ◽  
Pravat Kumar Mohapatra
Keyword(s):  
Grain Yield ◽  
Ethylene Production ◽  
Stem Elongation ◽  
Starch Synthesis ◽  
Acc Oxidase ◽  
Acc Synthase ◽  
Grain Filling ◽  
Soluble Carbohydrates ◽  
Rice Cultivars ◽  
Oxidase Enzyme

AbstractIn the recent time, Submergence1 (Sub1)QTL, responsible for imparting tolerance to flash flooding, has been introduced in many rice cultivars, but resilience of the QTL to stagnant flooding (SF) is not known. The response of Sub1-introgression has been tested on physiology, molecular biology and yield of two popular rice cultivars (Swarna and Savitri) by comparison of the parental and Sub1-introgression lines (SwarnaSub1 and SavitriSub1) under SF. Compared to control condition SF reduced grain yield and tiller number and increased plant height and Sub1- introgression mostly matched these effects. SF increased ethylene production by over-expression of ACC-synthase and ACC-oxidase enzyme genes of panicle before anthesis in the parental lines. Expression of the genes changed with Sub1-introgression, where some enzyme isoform genes over-expressed after anthesis under SF. Activities of endosperm starch synthesizing enzymes SUS and AGPase declined concomitantly with rise ethylene production in the Sub1-introgressed lines resulting in low starch synthesis and accumulation of soluble carbohydrates in the developing spikelets. In conclusion, Sub1-introgression into the cultivars increased susceptibility to SF. Subjected to SF, the QTL promoted genesis of ethylene in the panicle at anthesis to the detriment of grain yield, while compromising with morphological features like tiller production and stem elongation.

Harvest maturity related changes in the cold-induced activation of 1-aminocyclopropane-1-carboxylic acid metabolism in Granny Smith apples / Efecto del estado de madurez sobre la activación por frío del metabolismo del ácido 1-aminociclopropano-1-carboxílico en manzanas Granny Smith

1999 ◽  
Vol 5 (3) ◽  
pp. 223-228 ◽  
Author(s):  
C. Larrigaudiere ◽  
I. Recasens ◽  
J. Graell ◽  
M. Vendrell
Keyword(s):  
Carboxylic Acid ◽  
Ethylene Production ◽  
Oxidase Activity ◽  
Acid Metabolism ◽  
Cold Treatment ◽  
Acc Oxidase ◽  
Malus Domestica Borkh ◽  
Harvest Dates ◽  
Harmonization Process ◽  
Harvest Maturity

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.

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