scholarly journals A Combinatorial Interplay Among the 1-Aminocyclopropane-1-Carboxylate Isoforms Regulates Ethylene Biosynthesis in Arabidopsis thaliana

Genetics ◽  
2009 ◽  
Vol 183 (3) ◽  
pp. 979-1003 ◽  
Author(s):  
Atsunari Tsuchisaka ◽  
Guixia Yu ◽  
Hailing Jin ◽  
Jose M. Alonso ◽  
Joseph R. Ecker ◽  
...  
Keyword(s):  
Ethylene Production ◽  
Expression Patterns ◽  
Ethylene Biosynthesis ◽  
High Order ◽  
Phenotypic Characterization ◽  
Plant Signaling ◽  
In Planta ◽  
Entire Family ◽  
Key Enzyme ◽  
Interaction Map

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.

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 ◽  
...  
Keyword(s):  
Ethylene Production ◽  
Acc Oxidase ◽  
Ethylene Biosynthesis ◽  
Northern Analysis ◽  
Marker Genes ◽  
Total Protein Content ◽  
Protein Accumulation ◽  
Delayed Senescence ◽  
Transgenic Lines ◽  
Key Enzyme

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.

scholarly journals Rhythmic Serotonin N-Acetyltransferase mRNA Degradation Is Essential for the Maintenance of Its Circadian Oscillation

2005 ◽  
Vol 25 (8) ◽  
pp. 3232-3246 ◽  
Author(s):  
Tae-Don Kim ◽  
Jong-So Kim ◽  
Jong Heon Kim ◽  
Jihwan Myung ◽  
Hee-Don Chae ◽  
...  
Keyword(s):  
Circadian Rhythm ◽  
Expression Patterns ◽  
Mrna Level ◽  
Mrna Degradation ◽  
Circadian Oscillation ◽  
Oscillatory Mechanism ◽  
Key Enzyme ◽  
Mrna Profile ◽  
Species Specific ◽  
Nuclear Ribonucleoprotein

ABSTRACT Serotonin N-acetyltransferase (arylalkylamine N-acetyltransferase [AANAT]) is the key enzyme in melatonin synthesis regulated by circadian rhythm. To date, our understanding of the oscillatory mechanism of melatonin has been limited to autoregulatory transcriptional and posttranslational regulations of AANAT mRNA. In this study, we identify three proteins from pineal glands that associate with cis-acting elements within species-specific AANAT 3′ untranslated regions to mediate mRNA degradation. These proteins include heterogeneous nuclear ribonucleoprotein R (hnRNP R), hnRNP Q, and hnRNP L. Their RNA-destabilizing function was determined by RNA interference and overexpression approaches. Expression patterns of these factors in pineal glands display robust circadian rhythm. The enhanced levels detected after midnight correlate with an abrupt decline in AANAT mRNA level. A mathematical model for the AANAT mRNA profile and its experimental evidence with rat pinealocytes indicates that rhythmic AANAT mRNA degradation mediated by hnRNP R, hnRNP Q, and hnRNP L is a key process in the regulation of its circadian oscillation.

scholarly journals Aminoethoxyvinylglycine Inhibits Fruit Abscission Induced by Naphthaleneacetic Acid and Associated Relationships with Expression of Genes for Ethylene Biosynthesis, Perception, and Cell Wall Degradation in ‘Delicious’ Apples

2008 ◽  
Vol 133 (6) ◽  
pp. 727-734 ◽  
Author(s):  
Hong Zhu ◽  
Eric P. Beers ◽  
Rongcai Yuan
Keyword(s):  
Cell Wall ◽  
Ethylene Production ◽  
Acc Oxidase ◽  
Ethylene Biosynthesis ◽  
Naphthaleneacetic Acid ◽  
Cell Wall Degradation ◽  
Oxidase Gene ◽  
Young Fruit ◽  
Fruit Abscission ◽  
Expression Of Genes

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.

scholarly journals Plant trait heterosis is quantitatively associated with expression heterosis of the plastid ribosomal proteins

2021 ◽  
Author(s):  
Devon Birdseye ◽  
Laura A. de Boer ◽  
Hua Bai ◽  
Peng Zhou ◽  
Zhouxin Shen ◽  
...  
Keyword(s):  
Plant Height ◽  
Ribosomal Proteins ◽  
Protein Complexes ◽  
Expression Patterns ◽  
Ethylene Biosynthesis ◽  
Hybrid Vigor ◽  
Maize Hybrids ◽  
Protein Levels ◽  
Plant Trait ◽  
Elevated Expression

AbstractThe use of hybrids is widespread in agriculture, yet the molecular basis for hybrid vigor (heterosis) remains obscure. To identify molecular components that may contribute to the known higher photosynthetic capacity of maize hybrids, we generated paired datasets of the proteomes and transcriptomes from leaf tissues of maize hybrids and their inbred parents. Expression patterns in the hybrids were semi-dominant to overdominant for subunits of the digenomic protein complexes required for the light reactions of photosynthesis and for chloroplast protein synthesis; nuclear and plastid-encoded subunits were elevated similarly. These patterns were not mirrored in the nuclear transcriptomes. We compared growth to transcript and protein levels of multiple hybrids with varying levels of heterosis. Expression heterosis (hybrid/mid-parent expression levels) of chloroplast ribosomal proteins and of nuclear transcripts for the photosynthetic light reactions was positively correlated with plant height heterosis (hybrid/mid-parent plant height). Ethylene biosynthetic enzymes were expressed below mid-parent levels in the hybrids, and the ethylene biosynthesis mutant acs2/acs6 partially phenocopied the hybrid proteome, indicating that a reduction in ethylene biosynthesis may be upstream of the elevated expression of photosynthetic and ribosomal proteins in chloroplasts of hybrids.

scholarly journals Temporal Relationship between Ester Biosynthesis and Ripening Events in Bananas

2002 ◽  
Vol 127 (6) ◽  
pp. 998-1005 ◽  
Author(s):  
Sastry Jayanty ◽  
Jun Song ◽  
Nicole M. Rubinstein ◽  
Andrés Chong ◽  
Randolph M. Beaudry
Keyword(s):  
Chlorophyll Fluorescence ◽  
Ethylene Production ◽  
Temporal Relationship ◽  
Photochemical Efficiency ◽  
Acc Oxidase ◽  
Ethylene Biosynthesis ◽  
Banana Fruit ◽  
Coa Transferase ◽  
Ester Biosynthesis ◽  
Natural Ester

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.

scholarly journals Expression Patterns of ACS and ACO Gene Families and Ethylene Production in Rachis and Berry of Grapes

HortScience ◽  
2017 ◽  
Vol 52 (3) ◽  
pp. 413-422 ◽  
Author(s):  
Xia Ye ◽  
Xianbo Zheng ◽  
Dehua Zhai ◽  
Wen Song ◽  
Bin Tan ◽  
...  
Keyword(s):  
Ethylene Production ◽  
Expression Patterns ◽  
Acc Oxidase ◽  
Gene Families ◽  
Stress Factors ◽  
Transcriptional Level ◽  
Berry Development ◽  
Thompson Seedless ◽  
Expression Levels ◽  
Ethephon Treatment

Ethylene is important during the berry development and in the last stages of rachis development or rachis senescence. Since grapes develop in a cluster that comprises both the fruit berry and the nonfruit rachis, we measured the release of ethylene from both tissues. Detached berries from Vitis vinifera ‘Ruby Seedless’ and ‘Thompson Seedless’ showed that ethylene release peaks at the beginning of berry development and at veraison. Ethylene production in the rachis was higher than that in the berry and had an obvious peak before harvest in ‘Thompson Seedless’. In both cultivars, ethephon treatment induced ethylene production in the rachis but not in the berry. Expression of 1-aminocyclopropane-1-carboxylate (ACC) synthase (ACS) and ACC oxidase (ACO) genes showed diverse temporal and spatial patterns in ‘Thompson Seedless’ and ‘Ruby Seedless’. For most gene family members, the low ACS expression levels were observed in berry and rachis. Expression levels of most of the ACS and ACO genes did not correlate with ethylene released in the same organ. The transcriptional level of VvACS1 did correlate with ethylene evolution in rachis of ‘Thompson Seedless’ during berry development and storage, which suggested that VvACS1 may have important roles in rachis senescence. In berries of ‘Thompson Seedless’ and ‘Ruby Seedless’, the transcriptional levels of VvACO1, VvACS2, and VvACS6 coincided with ethylene production, indicating possible roles in berry development. Expression of VvACS2–VvACO9 and VvACO1–VvACO3 was not consistent with ethylene production during storage or in response to ethephon treatment, which suggests that the expression of ACS and ACO was affected by other stress factors after harvest.

scholarly journals Ethylene Biosynthesis and Signaling Is Required for Rice Immune Response and Basal Resistance Against Magnaporthe oryzae Infection

2016 ◽  
Vol 29 (11) ◽  
pp. 831-843 ◽  
Author(s):  
Emily E. Helliwell ◽  
Qin Wang ◽  
Yinong Yang
Keyword(s):  
Cell Death ◽  
Magnaporthe Oryzae ◽  
Ethylene Production ◽  
Ethylene Biosynthesis ◽  
Blast Disease ◽  
Intermediate Phenotype ◽  
Slight Reduction ◽  
Callose Deposition ◽  
Fungal Cell ◽  
Basal Resistance

Recent studies have suggested that ethylene enhances host resistance to fungal pathogen Magnaporthe oryzae, the causal agent of rice blast disease. Among the six 1-aminocyclopropane-1-carboxylic acid synthase genes in rice, OsACS1 and OsACS2 are induced within 24 h of inoculation by M. oryzae. This induction occurs simultaneously with an increase in ethylene production that is noticeable 12 h postinoculation. The purpose of this study was to examine the dynamics of ethylene production and signaling in wild type and RNA interference–mediated suppression lines deficient in ethylene production (acs2) or signaling (eil1) after challenge with M. oryzae as well as fungal cell-wall elicitors. Ethylene-insensitive mutant lines show an attenuated basal defense response including lower basal expression of the genes encoding a chitin-binding receptor, pathogenesis-related (PR) proteins, and the enzymes involved in the synthesis of diterprenoid phytoalexins, a reduction on early hypersensitive response (HR)-like cell death, and reduced incidence of callose deposition. Ethylene-deficient mutants showed an intermediate phenotype, with a significant reduction in expression of defense-related genes and callose deposition, but only a slight reduction in HR-like cell death. As a result, all ethylene-insensitive mutants show increased susceptibility to M. oryzae, whereas the ethylene-deficient lines show a slight but less significant increase in disease severity. These results show that ethylene signaling and, to some extent, ethylene production are required for rice basal resistance against the blast fungus Magnaporthe oryzae.

scholarly journals Ethylene is Involved in Symptom Development and Ribosomal Stress of Tomato Plants upon Citrus Exocortis Viroid Infection

Plants ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 582
Author(s):  
Francisco Vázquez Prol ◽  
M. Pilar López-Gresa ◽  
Ismael Rodrigo ◽  
José María Bellés ◽  
Purificación Lisón
Keyword(s):  
Ribosome Biogenesis ◽  
Ethylene Biosynthesis ◽  
Northern Blotting ◽  
Phenotypic Characterization ◽  
Disease Development ◽  
Tomato Plants ◽  
Susceptibility To Infection ◽  
Citrus Exocortis Viroid ◽  
Viroid Infection ◽  
Ribosomal Stress

Citrus exocortis viroid (CEVd) is known to cause different symptoms in citrus trees, and its mechanism of infection has been studied in tomato as an experimental host, producing ribosomal stress on these plants. Some of the symptoms caused by CEVd in tomato plants resemble those produced by the phytohormone ethylene. The present study is focused on elucidating the relationship between CEVd infection and ethylene on disease development. To this purpose, the ethylene insensitive Never ripe (Nr) tomato mutants were infected with CEVd, and several aspects such as susceptibility to infection, defensive response, ethylene biosynthesis and ribosomal stress were studied. Phenotypic characterization revealed higher susceptibility to CEVd in these mutants, which correlated with higher expression levels of both defense and ethylene biosynthesis genes, as well as the ribosomal stress marker SlNAC082. In addition, Northern blotting revealed compromised ribosome biogenesis in all CEVd infected plants, particularly in Nr mutants. Our results indicate a higher ethylene biosynthesis in Nr mutants and suggest an important role of this phytohormone in disease development and ribosomal stress caused by viroid infection.

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