Expression and functional analysis of PhEOL1 and PhEOL2 during flower senescence in petunia

2016 ◽  
Vol 43 (5) ◽  
pp. 413 ◽  
Author(s):  
Juanxu Liu ◽  
Ji Zhao ◽  
Zhina Xiao ◽  
Xinlei Chang ◽  
Guoju Chen ◽  
...  
Keyword(s):  
Petunia Hybrida ◽  
Ethylene Biosynthesis ◽  
Flower Senescence ◽  
Biosynthesis Pathway ◽  
Ethylene Treatment ◽  
Exogenous Ethylene ◽  
Rate Limiting ◽  
Two Hybrid

The ethylene biosynthesis pathway controls flower senescence. Previous studies have shown that Arabidopsis ETHYLENE-OVERPRODUCER1 (ETO1) interacts specifically with and negatively regulates type 2 1-aminocyclopropane-1-carboxylate synthases (ACSs), the rate-limiting enzymes of ethylene biosynthesis. The ethylene biosynthesis pathway controls flower senescence in petunias (Petunia hybrida Juss.). However, the role of ETO1-like genes (EOLs) during flower senescence has not been investigated. Here, two full-length petunia EOL cDNAs, PhEOL1 and PhEOL2, were isolated. RT–PCR assays indicated that the expression of PhEOL1 and PhEOL2 increased after exogenous ethylene treatment. The VIGS-mediated silencing of PhEOL1 accelerated flower senescence and produced more ethylene than the control condition, whereas the silencing of PhEOL2 did not. Notably, the effects caused by PhEOL1 suppression were not enhanced by PhEOL2 suppression in corollas. In addition, the expression of two petunia type 2 PhACS genes increased during flower senescence and after ethylene treatment. A yeast two-hybrid assay showed that PhEOL1 interacts with both PhACS2 and PhACS3. It is possible that PhEOL1 is involved in flower senescence by interacting with type 2 PhACSs in petunias.

scholarly journals A Positive Role for Rhizobitoxine in Rhizobium-legume Symbiosis

1999 ◽  
Vol 12 (12) ◽  
pp. 1082-1089 ◽  
Author(s):  
Samuel Duodu ◽  
T. V. Bhuvaneswari ◽  
Thomas J. W. Stokkermans ◽  
N. Kent Peters
Keyword(s):  
Ethylene Biosynthesis ◽  
Nodule Development ◽  
Ethylene Inhibitors ◽  
Wild Type ◽  
Positive Role ◽  
Rate Limiting Step ◽  
Mutant Strains ◽  
Legume Symbiosis ◽  
Exogenous Ethylene ◽  
Rate Limiting

Although Bradyrhizobium elkanii is a mutualistic symbiont of legumes, it synthesizes a phytotoxin, rhizobitoxine, that causes chlorosis on a variety of legume hosts, giving a pathogenic character to these interactions. No positive role for rhizobitoxine has been previously demonstrated. Interestingly, rhizobitoxine inhibits the rate-limiting step for ethylene biosynthesis, a plant hormone known to inhibit or down-regulate nodule development. We hypothesized that rhizobitoxine plays a positive role in nodule development through its inhibition of ethylene biosynthesis. To test this hypothesis, host plants of B. elkanii were screened for a differential nodulation response to the wild-type and rhizobitoxine mutant strains. In Vigna radiata (mungbean), the rhizobitoxine mutant strains induced many aborted nodules arrested at all stages of pre-emergent and post-emergent development and formed significantly fewer mature nodules than the wild type. Experiments revealed that nodulation of mungbean plants is sensitive to exogenous ethylene, and that the ethylene inhibitors aminoethoxyvinylglycine and Co2+ were able to partially restore a wild-type nodulation pattern to the rhizobitoxine mutants. This is the first demonstration of a nodulation phenotype of the rhizobitoxine mutants and suggests that rhizobitoxine plays a positive and necessary role in Rhizobium-legume symbiosis through its inhibition of ethylene biosynthesis.

Role of Ethylene in the Biosynthesis of Fatty Acid-Derived Volatiles in Tomato Fruits

2011 ◽  
Vol 343-344 ◽  
pp. 937-950
Author(s):  
Yuan Hong Xie ◽  
Hong Yan Gao ◽  
Yun Bo Luo ◽  
Hong Xing Zhang ◽  
Xiang Ning Chen ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Linolenic Acid ◽  
Tomato Fruit ◽  
Ethylene Biosynthesis ◽  
Hydroperoxide Lyase ◽  
Wild Type ◽  
Tomato Fruits ◽  
Aroma Volatiles ◽  
Exogenous Ethylene

Regulation of ethylene biosynthesis or action has an important effect on volatiles production in tomato (Lycopersicon esculentum) fruits. To understand the role of ethylene in the biosynthesis of fatty acid-derived aroma volatiles in tomato, we used Lichun tomato from a transgenic line with strictly suppression of ethylene biosynthesis (antisenseLeACS2tomato) and its wild type background line. This study was focused on the levels of the precursor substrates, activities and transcriptional levels of aroma volatile-related enzymes, including lipoxygenase (LOX), hydroperoxide lyase (HPL) and alcohol dehydrogenase (ADH). We also investigated the different abilities of converting the precursor substrates to aroma volatiles in ethylene suppressed transgenic and wild-type (WT) tomato fruits. Our results showed that the contents of endogenous linoleic and linolenic acid in tomato fruits were ethylene depended. Suppression of ethylene biosynthesis increased the content of endogenous linolenic acid inLichuntomato fruit and then declined the ratio of linoleic /linolenic acid. Exogenous ethylene changed the value of linoleic acid /linolenic acid in antisenseLeACS2(ACS) tomato fruit to the similar level of WT. During the ripening of wild type Lichun tomato fruit, LOX activity was ethylene and development dependent. Suppression of ethylene biosynthesis did not inhibit the transcriptional expression ofLoxCgene. And the HPL and ADH activities were partial ethylene-dependent during the ripening of wild typeLichuntomato fruit. Moreover, suppression of ethylene biosynthesis also affected the bioconversion of unsaturated-fatty acid precursors to C6 aldehydes and C6 alcohols. All these results indicated that ethylene had complicated effects on the biosynthesis of fatty acid-derived armoa volatiles by affecting the precursor’s content, enzyme activities, enzyme expression and the substrate utilization.

scholarly journals Diurnal down-regulation of ethylene biosynthesis mediates biomass heterosis

2018 ◽  
Vol 115 (21) ◽  
pp. 5606-5611 ◽  
Author(s):  
Qingxin Song ◽  
Atsumi Ando ◽  
Dongqing Xu ◽  
Lei Fang ◽  
Tianzhen Zhang ◽  
...  
Keyword(s):  
Biological Networks ◽  
Ethylene Production ◽  
Molecular Mechanisms ◽  
Ethylene Biosynthesis ◽  
Superior Performance ◽  
F1 Hybrids ◽  
Down Regulation ◽  
Negative Role ◽  
Exogenous Ethylene

Heterosis is widely applied in agriculture; however, the underlying molecular mechanisms for superior performance are not well understood. Ethylene biosynthesis and signaling genes are shown to be down-regulated in Arabidopsis interspecific hybrids. Ethylene is a plant hormone that promotes fruit ripening and maturation but inhibits hypocotyl elongation. Here we report that application of exogenous ethylene could eliminate biomass vigor in Arabidopsis thaliana F1 hybrids, suggesting a negative role of ethylene in heterosis. Ethylene biosynthesis is mediated by the rate-limiting enzyme, 1-aminocyclopropane-1-carboxylate synthase (ACS). Down-regulation of ACS genes led to the decrease of ethylene production, which was associated with the high-vigor F1 hybrids, but not with the low-vigor ones. At the mechanistic level, expression of ACS genes was down-regulated diurnally and indirectly by Circadian Clock Associated 1 (CCA1) during the day and directly by Phyotochrome-Interacting Factor 5 (PIF5) at night. Consistent with the negative role of ethylene in plant growth, biomass vigor was higher in the acs mutants than in wild-type plants, while increasing endogenous ethylene production in the hybridizing parents reduced growth vigor in the hybrids. Thus, integrating circadian rhythms and light signaling into ethylene production is another regulatory module of complex biological networks, leading to biomass heterosis in plants.

scholarly journals Systems Biology Applied to the Study of Papaya Fruit Ripening: The Influence of Ethylene on Pulp Softening

Cells ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 2339
Author(s):  
Caroline Giacomelli Soares ◽  
Samira Bernardino Ramos do Prado ◽  
Sónia C. S. Andrade ◽  
João Paulo Fabi
Keyword(s):  
Gene Expression ◽  
Cell Wall ◽  
Ethylene Biosynthesis ◽  
High Rate ◽  
Physiological Data ◽  
Fleshy Fruit ◽  
Ethylene Treatment ◽  
Coordinated Expression ◽  
Commercially Important

Papaya is a fleshy fruit that undergoes fast ethylene-induced modifications. The fruit becomes edible, but the fast pulp softening is the main factor that limits the post-harvest period. Papaya fast pulp softening occurs due to cell wall disassembling coordinated by ethylene triggering that massively expresses pectinases. In this work, RNA-seq analysis of ethylene-treated and non-treated papayas enabled a wide transcriptome overview that indicated the role of ethylene during ripening at the gene expression level. Several families of transcription factors (AP2/ERF, NAC, and MADS-box) were differentially expressed. ACO, ACS, and SAM-Mtase genes were upregulated, indicating a high rate of ethylene biosynthesis after ethylene treatment. The correlation among gene expression and physiological data demonstrated ethylene treatment can indeed simulate ripening, and regulation of changes in fruit color, aroma, and flavor could be attributed to the coordinated expression of several related genes. Especially about pulp firmness, the identification of 157 expressed genes related to cell wall metabolism demonstrated that pulp softening is accomplished by a coordinated action of several different cell wall-related enzymes. The mechanism is different from other commercially important fruits, such as strawberry, tomato, kiwifruit, and apple. The observed behavior of this new transcriptomic data confirms ethylene triggering is the main event that elicits fast pulp softening in papayas.

scholarly journals 349 Studies on Postharvest Performance of Cut Racemes of Big Bend Bluebonnet

HortScience ◽  
1999 ◽  
Vol 34 (3) ◽  
pp. 503D-503
Author(s):  
W.A. Mackay ◽  
D. Sankhla ◽  
T.D Davis ◽  
N. Sankhla
Keyword(s):  
Ethylene Biosynthesis ◽  
Flower Senescence ◽  
Delayed Senescence ◽  
West Texas ◽  
Big Bend ◽  
Highly Sensitive ◽  
Ethylene Action ◽  
And Performance ◽  
Flower Abscission

Racemes of Big Bend bluebonnet (Lupinus havardii Wats.), a winter annual native to far west Texas with attractive blue flowers, are currently being produced commercially as a specialty cut-flower crop. Our studies indicated that the key determinants of postharvest longevity and performance are flower abscission and flower senescence, both of which can be influenced by ethylene. Therefore, this study was undertaken to evaluate the role of some ethylene biosynthesis inhibitors (aminooxy acetic acid = AOA; cobalt = CO++; salicylic acid = SA) and an ethylene action inhibitor (silver thiosulfate = STS) on flower abscission and flower senescence of bluebonnet racemes. Depending on the concentration used (10 μM - 1 mM), AOA and CO++ exhibited variable effects on flower abscission, flower senescence and vaselife. SA (10-100 μM) slightly delayed senescence but did not affect abscission, while higher levels of SA (500 μM - 2 mM) slightly promoted abscission and also significantly enhanced the senescence of flowers on cut racemes. The effects of SA were found to be pH-dependent. However, STS nearly eliminated flower abscission and enhanced vaselife. The results also demonstrated that the abscission of bluebonnet flowers, in particular, is highly sensitive to ethylene.

The effect of ReTain plant growth regulator [aminoethoxyvinylglycine (AVG)] on the postharvest storage life of 'Tegan Blue' plums

2003 ◽  
Vol 43 (5) ◽  
pp. 515 ◽  
Author(s):  
J. Jobling ◽  
R. Pradhan ◽  
S. C. Morris ◽  
L. Mitchell ◽  
A. C. Rath
Keyword(s):  
Plant Growth ◽  
Growth Regulator ◽  
Ethylene Production ◽  
Plant Growth Regulator ◽  
Acc Synthase ◽  
Ethylene Biosynthesis ◽  
Biosynthesis Pathway ◽  
Commercial Formulation ◽  
Significant Difference ◽  
Rate Limiting

ReTain plant growth regulator is a commercial formulation of aminoethoxyvinylglycine (AVG). This compound is known to competitively inhibit the activity of the enzyme ACC (1-aminocyclopropanecarboxylate) synthase which is the rate limiting enzyme in the ethylene biosynthesis pathway. By inhibiting the activity of ACC synthase, ethylene-mediated ripening processes can be delayed.'Tegan Blue' plums have low ethylene production, which indicates that it is a suppressed climacteric variety. There was a significant difference between the ReTain treated and untreated fruit for the second harvest, this difference was greater later in storage than early in storage. The results indicate that there is a postharvest benefit achieved after applying AVG to 'Tegan Blue' plums. The main advantage is in the maintenance of firmness for late-harvested fruit. Other benefits are the suppression of ethylene production and the development of a more intense colour.

scholarly journals 1010 DELAYED PETAL SENESCENCE IN TRANSGENIC CARNATION USING ANTISENSE ACC OXIDASE

HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 574c-574 ◽  
Author(s):  
Keith W. Savin ◽  
Stanley C. Baudinette ◽  
Michael W. Graham ◽  
Ellen L-J. White ◽  
Michael Z. Michael ◽  
...  
Keyword(s):  
Acc Oxidase ◽  
Acc Synthase ◽  
Wound Response ◽  
Flower Senescence ◽  
Vase Life ◽  
Ethylene Inhibitors ◽  
Silver Thiosulphate ◽  
Adenosyl Methionine ◽  
Exogenous Ethylene

Ethylene is essential for the senescence process in many fruit and flowers. In the last two steps in the biosynthesis of ethylene in plants ACC synthase converts S-adenosyl methionine to 1-aminocyclopropane-1-carboxylic acid(ACC). ACC oxidase (ACO) then degrades ACC to ethylene. Inhibitors of ethylene synthesis, such as amino-oxyacetic acid, and of the response to ethylene, such as silver thiosulphate, delay or prevent senescence. By expression of an antisense version of ACO RNA, we have generated two varieties of transgenic carnation which produce flowers with an extended vase life. These were produced using the cultivars Red Sim and White Sim. Flowers from these plants produce very little ethylene and normally fail to display the inrolling phenotype typical of senescence in this species. At the time after harvest when inrolling would normally lake place (5 days), the antisense ACO flowers produce only barely detectable levels of endogenous ACO mRNA or ACS (ACC Synthase) mRNA. Exposure to exogenous ethylene(100ppm) induces inrolling and production of ACS and ACO mRNA species. Such carnations will be valuable both as a commercial product and as a tool for further exploring the role of ethylene in carnation flower senescence and leaf wound response.

scholarly journals Variation in Flower Senescence and Ethylene Biosynthesis among Carnations

HortScience ◽  
1992 ◽  
Vol 27 (10) ◽  
pp. 1100-1102 ◽  
Author(s):  
Amanda S. Brandt ◽  
William R. Woodson
Keyword(s):  
Dianthus Caryophyllus ◽  
Acc Synthase ◽  
Ethylene Biosynthesis ◽  
Enzyme Treatment ◽  
Flower Senescence ◽  
Vase Life ◽  
Petal Senescence ◽  
Ethylene Treatment ◽  
Initial Symptoms ◽  
Visible Symptom

We have investigated the patterns of ethylene biosynthesis in carnation (Dianthus caryophyllus L.) genotypes that exhibit extended vase life in comparison to flowers of White Sim'. `White Sim' flowers exhibited typical symptoms of senescence, including petal in-rolling and rapid wilting, beginning 5 days after harvest. In contrast, the other genotypes studied did not show petal in-rolling or rapid wilting associated with petal senescence. The first visible symptom of senescence in these flowers was necrosis of the petal tips, and it occurred from 3 to 7 days after the initial symptoms of senescence were seen in `White Sim' flowers. In all cases, the extended-vase-life genotypes did not exhibit the dramatic increase in ethylene production that typically accompanies petal senescence in carnation. This appeared to be the result of limited accumulation of ACC. In addition, flowers of these genotypes had limited capacity to convert ACC to ethylene. Therefore, we conclude that the low level of ethylene produced by these flowers during postharvest aging is the result of low activities of both ACC synthase and the ethylene-forming enzyme. Treatment of `White Sim' flowers at anthesis with 1.0 μl ethylene/liter resulted in the induction of increased ethylene biosynthesis and premature petal senescence. The extended-vase-life genotypes exhibited varying responses to ethylene treatment. One genotype (87-37G-2) produced elevated ethylene and senesced prematurely, as did flowers of `White Sim'. A second genotype (82-1) was induced to senesce by ethylene treatment but did not produce increased ethylene. A third genotype (799) was unaffected by ethylene treatment. The results of this study suggest these extended-vase-life genotypes are representative of genetic differences in the capacity to synthesize and respond to ethylene. Chemical name used: 1-aminocyclopropane-1-carboxylic acid (ACC).

Mechanisms of ethylene biosynthesis and response in plants

2015 ◽  
Vol 58 ◽  
pp. 61-70 ◽  
Author(s):  
Paul B. Larsen
Keyword(s):  
Plant Growth ◽  
Growth And Development ◽  
Ethylene Biosynthesis ◽  
Unsaturated Hydrocarbon ◽  
Flower Senescence ◽  
Detailed Knowledge ◽  
Plant Growth And Development ◽  
Step Process ◽  
Ethylene Response ◽  
Ethylene Signalling

Ethylene is the simplest unsaturated hydrocarbon, yet it has profound effects on plant growth and development, including many agriculturally important phenomena. Analysis of the mechanisms underlying ethylene biosynthesis and signalling have resulted in the elucidation of multistep mechanisms which at first glance appear simple, but in fact represent several levels of control to tightly regulate the level of production and response. Ethylene biosynthesis represents a two-step process that is regulated at both the transcriptional and post-translational levels, thus enabling plants to control the amount of ethylene produced with regard to promotion of responses such as climacteric flower senescence and fruit ripening. Ethylene production subsequently results in activation of the ethylene response, as ethylene accumulation will trigger the ethylene signalling pathway to activate ethylene-dependent transcription for promotion of the response and for resetting the pathway. A more detailed knowledge of the mechanisms underlying biosynthesis and the ethylene response will ultimately enable new approaches to be developed for control of the initiation and progression of ethylene-dependent developmental processes, many of which are of horticultural significance.

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