Senescence-associated down-regulation of 1-aminocyclopropane-1-carboxylate (ACC) oxidase delays harvest-induced senescence in broccoli

2005 ◽  
Vol 32 (10) ◽  
pp. 891 ◽  
Author(s):  
Nigel E. Gapper ◽  
Simon A. Coupe ◽  
Marian J. McKenzie ◽  
Richard W. Scott ◽  
Mary C. Christey ◽  
...  

To gain an in-depth understanding of the role of ethylene in post harvest senescence, we used broccoli (Brassica oleracea var. italica) as our model species. The senescence-associated asparagine synthetase (AS) promoter from asparagus was used to drive the expression of an antisense 1-aminocyclopropane-1-carboxylate oxidase (ACO) cDNA from broccoli, BoACO2, to reduce ethylene production following harvest. Physiological analyses revealed that transgenic broccoli lines harbouring the antisense BoACO2 gene construct (designated as AS-asACO) displayed delayed senescence in both detached leaves and detached heads as measured by hue angle. Harvested floret tissue from these plants also showed a delayed loss of chlorophyll, lower protease activity and higher total protein content, and changes in transcript levels of senescence marker genes when compared with wild type and transgenic lines transformed with an empty T-DNA. Genes that were down-regulated included those coding for cysteine protease (BoCP5), metallothionein-like protein (BoMT1), hexokinase (BoHK1), invertase (BoINV1) and sucrose transporters (BoSUC1 and BoSUC2). Northern analysis for BoACO1 and BoACO2, ACO assays and western analysis, revealed reduced ACO transcript, enzyme activity and protein accumulation, as well as reduced ethylene production in the transgenic AS-asACO lines when compared with controls, confirming that a key enzyme regulating ethylene biosynthesis was reduced in these plants. This, together with the changes observed in gene expression, confirm a significant role for ethylene in regulating the events leading to senescence in broccoli following harvest.

2008 ◽  
Vol 133 (6) ◽  
pp. 727-734 ◽  
Author(s):  
Hong Zhu ◽  
Eric P. Beers ◽  
Rongcai Yuan

Effects of naphthaleneacetic acid (NAA) and aminoethoxyvinylglycine (AVG) on young fruit abscission, leaf and fruit ethylene production, and expression of genes related to ethylene biosynthesis and cell wall degradation were examined in ‘Delicious’ apples (Malus ×domestica Borkh.). NAA at 15 mg·L−1 increased fruit abscission and ethylene production of leaves and fruit when applied at the 11-mm stage of fruit development, whereas AVG, an inhibitor of ethylene biosynthesis, at 250 mg·L−1 reduced NAA-induced fruit abscission and ethylene production of leaves and fruit. NAA also increased expression of 1-aminocyclopropane-1-carboxylate (ACC) synthase genes (MdACS5A and MdACS5B), ACC oxidase gene (MdACO1), and ethylene receptor genes (MdETR1a, MdETR1b, MdETR2, MdERS1, and MdERS2) in fruit cortex and fruit abscission zones. However, AVG reduced NAA-induced expression of these genes except for MdERS2 in fruit abscission zones. NAA increased expression of the polygalacturonase gene MdPG2 in fruit abscission zones but not in fruit cortex, whereas AVG reduced NAA-enhanced expression of MdPG2 in fruit abscission zones. The expression of β-1,4-glucanase gene MdCel1 in fruit abscission zones was decreased by NAA but was unaffected by AVG. Our results suggest that ethylene biosynthesis, ethylene perception, and the MdPG2 gene are involved in young fruit abscission caused by NAA.


2002 ◽  
Vol 127 (6) ◽  
pp. 998-1005 ◽  
Author(s):  
Sastry Jayanty ◽  
Jun Song ◽  
Nicole M. Rubinstein ◽  
Andrés Chong ◽  
Randolph M. Beaudry

The temporal relationship between changes in ethylene production, respiration, skin color, chlorophyll fluorescence, volatile ester biosynthesis, and expression of ACC oxidase (ACO) and alcohol acyl-CoA transferase (AAT) in ripening banana (Musa L. spp., AAA group, Cavendish subgroup. `Valery') fruit was investigated at 22 °C. Ethylene production rose to a peak a few hours after the onset of its logarithmic phase; the peak in production coincided with maximal ACO expression. The respiratory rise began as ethylene production increased, reaching its maximum ≈30 to 40 hours after ethylene production had peaked. Green skin coloration and photochemical efficiency, as measured by chlorophyll fluorescence, declined simultaneously after the peak in ethylene biosynthesis. Natural ester biosynthesis began 40 to 50 hours after the peak in ethylene biosynthesis, reaching maximal levels 3 to 4 days later. While AAT expression was detected throughout, the maximum level of expression was detected at the onset of natural ester biosynthesis. The synthesis of unsaturated esters began 100 hours after the peak in ethylene and increased with time, suggesting the lipoxygenase pathway be a source of ester substrates late in ripening. Incorporation of exogenously supplied ester precursors (1-butanol, butyric acid, and 3-methyl-1-butanol) in the vapor phase into esters was maturity-dependent. The pattern of induced esters and expression data for AAT suggested that banana fruit have the capacity to synthesize esters over 100 hours before the onset of natural ester biosynthesis. We hypothesize the primary limiting factor in ester biosynthesis before natural production is precursor availability, but, as ester biosynthesis is engaged, the activity of alcohol acyl-CoA transferase the enzyme responsible for ester biosynthesis, exerts a major influence.


HortScience ◽  
1998 ◽  
Vol 33 (1) ◽  
pp. 103-104
Author(s):  
Hirofumi Terai ◽  
Hironobu Tsuchida ◽  
Masashi Mizuno ◽  
Noriyoshi Matsui

Tomato fruit were given a short-term (24 h) high CO2 (80%) or N2 (100%) treatment and then transferred to air storage at 20 °C. The CO2 treatment stimulated ACC oxidase activity and ethylene production, whereas the N2 treatment increased ACC content but did not increase ethylene production. Both CO2, and N2 treatments delayed ripening for one day, but fruit ripened normally. Although short-term 80% CO2, had a stimulating effect, and 100 % N2 had no effect on ethylene production, ripening was delayed slightly by both treatments. Chemical name used: 1-aminocyclopropane-1-carboxylic acid (ACC).


2007 ◽  
Vol 13 (6) ◽  
pp. 497-504
Author(s):  
L. Zacarías ◽  
F. Alférez

The effect of carbon dioxide (CO2) on wound-induced ethylene biosynthesis in flavedo discs of mature orange fruits (Citrus sinensis L. Osbeck) is investigated. Wounding induced a marked and rapid increase on the rate of ethylene production, the content of 1-aminocyclopropane-1-carboxylic acid (ACC) and on the in vivo ACC oxidase (ACO) activity. Incubation of flavedo discs in a 15% CO2 atmosphere suppressed activation of these processes. Wound-induced ethylene production was inhibited by CO2 in a concentration-dependent manner but ACO activity was enhanced at concentrations between 1% and 5%. Kinetic analysis of the interaction between CO2 and ACO activity indicated that high CO2 acted as a noncompetitive inhibitor. Removal of CO2 after 24 h incubation did not restore normal rates of ethylene production. CO2 partially counteracted the increase in ethylene production and ACO activity induced by a pretreatment with an ethylene action inhibitor (STS, silver thiosulfate). This suggested that part of CO2 action on ethylene biosynthesis might be due to interfering ethylene action. Collectively, the results indicated that ACS activity appeared to be the major regulatory step by which CO2 suppresses wound-induced ethylene production. ACO was differentially modulated by CO2, which is being stimulated at low concentrations and inhibited at high concentrations.


2015 ◽  
Vol 9 (12) ◽  
pp. 125 ◽  
Author(s):  
Piyanuch Sornchai ◽  
Sermsiri Chanprame

<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>


2021 ◽  
Vol 12 ◽  
Author(s):  
Aung Htay Naing ◽  
Hui Yeong Jeong ◽  
Sung Keun Jung ◽  
Chang Kil Kim

Abiotic stress induces the ethylene precursor 1-aminocyclopropane-1-carboxylic acid (ACC) in plants, which consequently enhances ethylene production and inhibits plant growth. The bacterial ACC deaminase enzyme encoded by the acdS gene reduces stress-induced ethylene production and improves plant growth in response to stress. In this study, overexpression of acdS in Petunia hybrida (‘Mirage Rose’) significantly reduced expression of the ethylene biosynthesis gene ACC oxidase 1 (ACO1) and ethylene production relative to those in wild type (WT) under various abiotic stresses (cold, drought, and salt). The higher reduction of stress-induced ethylene in the transgenic plants, which was due to the overexpression of acdS, led to a greater tolerance to the stresses compared to that in the WT plants. The greater stress tolerances were proven based on better plant growth and physiological performance, which were linked to stress tolerance. Moreover, expression analysis of the genes involved in stress tolerance also supported the increased tolerance of transgenics relative to that with the WT. These results suggest the possibility that acdS is overexpressed in ornamental plants, particularly in bedding plants normally growing outside the environment, to overcome the deleterious effect of ethylene on plant growth under different abiotic stresses. The development of stress-tolerant plants will be helpful to advance the floricultural industry.


Author(s):  
Zs. Galli ◽  
E. Kiss ◽  
G. Hrazdina ◽  
L. Heszky

A detailed examination of the production of ethylene and other ripening parameters during storage period has been undertaken in transgenic apple fruits, where the ethylene biosynthesis was inhibited by antisense ACS (l-aminocyclopropane-l-carboxylate synthase) gene. Data indicate down regulation of ethylene production, softening and spoilage in some transgenic lines. In some cases ethylene production was inhibited for over 90 percent, considerable reduction of softening and spoilage was observed probably due to the reduced activity of cell wall degradable enzymes. ACS activity was also monitored during ripening. The fruits of the best transgenic lines could be stored for minimum 4-5 months longer under 5 °C cold room storage conditions and one month longer at normal room temperature. This molecular approach can provide an alternative way to replace the commonly used and costly atmospheric storage of fruits.


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.


2014 ◽  
Vol 1033-1034 ◽  
pp. 677-680
Author(s):  
Ling Li ◽  
Hai Xue Liu ◽  
Yong Bo Peng ◽  
Shi Li ◽  
Tie Ling Liu

The flesh firmness of AC andrinmutant tomato fruits picked freshly were the largest. Respiration rate and ethylene production were very low at this time. With ethylene production increase, fruit firmness began to decline. 100μL/L ethephon significantly increased AC tomato fruit ethylene release, respiration rate, ACS activity and ACO activity, and decreased flesh firmness. However, there were no significant differences inrinmutant between control and ethephon treatment. It was shown RIN transcription factor regulated ethylene biosynthesis by ACC synthase and ACC oxidase.


Genetics ◽  
2009 ◽  
Vol 183 (3) ◽  
pp. 979-1003 ◽  
Author(s):  
Atsunari Tsuchisaka ◽  
Guixia Yu ◽  
Hailing Jin ◽  
Jose M. Alonso ◽  
Joseph R. Ecker ◽  
...  

Ethylene (C2H4) is a unique plant-signaling molecule that regulates numerous developmental processes. The key enzyme in the two-step biosynthetic pathway of ethylene is 1-aminocyclopropane-1-carboxylate synthase (ACS), which catalyzes the conversion of S-adenosylmethionine (AdoMet) to ACC, the precursor of ethylene. To understand the function of this important enzyme, we analyzed the entire family of nine ACS isoforms (ACS1, ACS2, ACS4-9, and ACS11) encoded in the Arabidopsis genome. Our analysis reveals that members of this protein family share an essential function, because individual ACS genes are not essential for Arabidopsis viability, whereas elimination of the entire gene family results in embryonic lethality. Phenotypic characterization of single and multiple mutants unmasks unique but overlapping functions of the various ACS members in plant developmental events, including multiple growth characteristics, flowering time, response to gravity, disease resistance, and ethylene production. Ethylene acts as a repressor of flowering by regulating the transcription of the FLOWERING LOCUS C. Each single and high order mutant has a characteristic molecular phenotype with unique and overlapping gene expression patterns. The expression of several genes involved in light perception and signaling is altered in the high order mutants. These results, together with the in planta ACS interaction map, suggest that ethylene-mediated processes are orchestrated by a combinatorial interplay among ACS isoforms that determines the relative ratio of homo- and heterodimers (active or inactive) in a spatial and temporal manner. These subunit isoforms comprise a combinatorial code that is a central regulator of ethylene production during plant development. The lethality of the null ACS mutant contrasts with the viability of null mutations in key components of the ethylene signaling apparatus, strongly supporting the view that ACC, the precursor of ethylene, is a primary regulator of plant growth and development.


Sign in / Sign up

Export Citation Format

Share Document