scholarly journals Molecular Genetic Analysis of Pollination-Induced Senescence in Phalaenopsis Orchids

1991 ◽  
Author(s):  
Sharman O'Neill ◽  
Abraham Halevy ◽  
Amihud Borochov
Keyword(s):  
Signal Transduction ◽  
Ethylene Production ◽  
Saturated Fatty Acids ◽  
Molecular Genetic ◽  
Acc Oxidase ◽  
Acc Synthase ◽  
Flower Senescence ◽  
Sensitivity Factor ◽  
Biochemical Basis ◽  
Ethylene Sensitivity

The project investigated the molecular genetic and biochemical basis of pollination-induced senescence of Phalaenopsis flowers. This experimental system offered unique advantages in that senescence is strictly regulated by pollination, providing the basis to experimentally initiate and synchronize senescence in populations of flowers. The postpollination syndrome in the Phalaenopsis orchid system was dissected by investigating the temporal and spatial regulation of ACC synthase gene expression. In the stigma, pollen-borne auxin induces the expression of the auxin-regulated ACC synthase (PS-ACS2) gene, resulting in ACC synthesis within 1 h following pollination. Newly formed ACC is oxidized by basal constitutive ACC oxidase to ethylene, which then induces the expression of the ethylene-regulated ACC synthase(PS-ACS1) and oxidase (ACO1) genes for further autocatalytic production of ethylene. It is speculated that during the 6-h period following pollination, emasculation leads to the production or release of a sensitivity factor that sensitizes the cells of the stigma to ethylene. ACC and ethylene molecules are translocated from the stigma to the labellum and perianth where ethylene induces the expression of PS-ACS1 and ACO1 resulting in an increased production of ACC and ethylene. Organ-localized ethylene is responsible for inrolling and senescence of the labellum and perianth. The regulation of ethylene sensitivity and signal transduction events in pollinated flowers was also investigated. The increase in ethylene sensitivity appeared in both the flower column and the perianth, and was detected as early as 4 h after pollination. The increase in ethylene sensitivity following pollination was not dependent on endogenous ethylene production. Application of linoleic and linoleic acids to Phalaenopsis and Dendrobium flowers enhanced their senescence and promoted ethylene production. Several major lipoxygenase pathway products including JA-ME, traumatic acid, trans-2-hexenal and cis-3-hexenol, also enhanced flower senescence. However, lipoxygenase appears to not be directly involved in the endogenous regulation of pollination-induced Phalaenopsis and Dendrobium flower senescence. The data suggest that short-chain saturated fatty acids may be the ethylene "sensitivity factors" produced following pollination, and that their mode of action involves a decrease in the order of specific regions i the membrane lipid bilayer, consequently altering ethylene action. Examination of potential signal transduction intermediates indicate a direct involvement of GTP-binding proteins, calcium ions and protein phosphorylation in the cellular signal transduction response to ethylene following pollination. Modulations of cytosolic calcium levels allowed us to modify the flowers responsiveness to ethylene.

scholarly journals Expression of Ethylene Biosynthetic Genes in the Gynoecium and Receptacle Associated With Sepal Abscission During Senescence in Delphinium Grandiflorum

2021 ◽  
Author(s):  
Mitsutoshi Okamoto ◽  
Tomoko Niki ◽  
Mirai Azuma ◽  
Kenichi Shibuya ◽  
Kazuo Ichimura
Keyword(s):  
Gene Expression ◽  
Carboxylic Acid ◽  
Ethylene Production ◽  
Acc Oxidase ◽  
Acc Synthase ◽  
Transcript Level ◽  
Flower Senescence ◽  
Biosynthetic Genes ◽  
Transcript Levels ◽  
Highly Sensitive

Abstract Delphinium flowers are highly sensitive to ethylene and its sepals abscise during senescence, which is associated with increases in 1-aminocyclopropane-1-carboxylic acid (ACC) synthase (ACS) and ACC oxidase (ACO) activities and ethylene production in gynoecium and receptacle. Three ACS genes (DgACS1, DgACS2, and DgACS3) and three ACO genes (DgACO1, DgACO2, and DgACO3) were cloned from Delphinium grandiflorum cv. Super Grand Blue. To investigate the contribution of these genes to ethylene production, their expression was analyzed in these genes in the gynoecium and receptacle during natural senescence and following ethylene exposure and pollination. Ethylene production in the gynoecium and receptacle increased during natural flower senescence. The transcript levels of the ACS and ACO genes in these organs, excluding DgACS2 in the receptacle, increased during senescence. Exposure to ethylene accelerated sepal abscission and more strongly increased ethylene production in the receptacle than in the gynoecium. DgACS1 transcript levels in the gynoecium and DgACS2 and DgACO3 transcript levels in the receptacle were increased by ethylene exposure. Pollination accelerated sepal abscission and increased ethylene production in the gynoecium and receptacle. Pollination slightly affected ACS and ACO transcript levels in the gynoecium, whereas DgACO3 transcript level in the receptacle were markedly increased. These results reveal that ACS and ACO gene expression is differently regulated in the gynoecium and receptacle, and some of these genes are more strongly upregulated by ethylene exposure and pollination in the receptacle than in the gynoecium, suggesting the significance of the receptacle to sepal abscission.

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.

scholarly journals Physiological and Molecular Characterization of the Response to Ethylene during Senescence of Carnation Genotypic Variants

1995 ◽  
Author(s):  
William Woodson ◽  
Shimon Mayak ◽  
Haim Rabinowitch
Keyword(s):  
Ethylene Production ◽  
Dianthus Caryophyllus ◽  
Acc Oxidase ◽  
Acc Synthase ◽  
Early Response ◽  
Vase Life ◽  
Petal Senescence ◽  
Ethylene Treatment ◽  
Novel Proteins ◽  
Exogenous Ethylene

The senescence of carnation (Dianthus caryophyllus L.) flowers is associated with increased production of the phytohormone ethylene, which in turn serves to initiate and regulate the processes involved in programmed petal death. We investigated the regulation of ethylene production and petal senescence in carnation. Several carnation genotypes were identified that exhibited extended vase-life in comparison to flowers from typical commercial cultivars. The capacity of these genotypes to produce ethylene during postharvest vase-life and to respond to exogenous ethylene was investigated. Several genotypes, represented by 'Sandrosa' and 87-37G produced little ethylene durig their postharvest vase-life and as a result failed to exhibit the symptoms (in-rolling and wilting) typical of flowers producing elevated levels of ethylene. These genotypes were further separated by their capacity to respond to exogenous ethylene by both increased ethylene synthesis and premature petal senescence. In one case a genotype (799) was identified that was not capable of responding to exogenous ethylene by either increased ethylene production or premature petal senescence. The regulation of ethylene production during petal senescence was investigated both at the enzyme and gene levels. A full length cDNA was identified for the petal senescence-related ACC synthase gene. Utilizing this, and other ethylene biosynthetic pathway cDNA probes, an increase in both ACC synthase and ACC oxidase mRNAs were detected following ethylene treatment. An increase in ACC oxidase mRNA and enzyme activity was detected within 2-3 h following ethylene treatment, indicating the expression of this gene is an early response to ethylene. An investigation into the expression of novel proteins during petal senescence revealed a number of polypeptides increased in abundance and possibly play a role in the regulation or biochemical processes of senescence. One polypeptide of 70 kDa was identified as being encoded by the previously characterized gene SR12 and possibly represents a b-galactosidase involved in the remobilization of carbohydrates during senescence.

scholarly journals Heat Treatments Delay and Reduce the Ethylene Climacteric in Carnation Flowers (Dianthus caryophyllus L. cv. `White Sim')

HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 460B-460
Author(s):  
Sven Verlinden ◽  
William R. Woodson
Keyword(s):  
Heat Treatment ◽  
Ethylene Production ◽  
Dianthus Caryophyllus ◽  
Acc Oxidase ◽  
Acc Synthase ◽  
Heat Treatments ◽  
Horticultural Crops ◽  
Beneficial Effects ◽  
Heat Treated ◽  
And Control

High-temperature treatments can be used for disinfestation of a variety of horticultural crops. Carnation flowers were subjected to a heat treatment in order to determine if it is a viable option for disinfestation of this crop. Flowers were exposed to 45°C for 24 hr in the dark, while control flowers were held at RT for 24 hr in the dark. Subsequently, the flowers were held at RT in the light and monitored for ethylene production, an indicator of imminent floral senescence. In the heat-treated flowers, the ethylene climacteric occurred at 96 hr after the heat treatment, a delay of 12 hr when compared to the control. Peak ethylene production was decreased by 25% to 30% in heat-treated flowers. Northern blot analysis of the ethylene biosynthetic pathway genes, ACC synthase, and ACC oxidase, showed that the expression of these genes is delayed by 8 to 16 hr in heat-treated flowers. This indicates that the delay and decrease in ethylene production is at least, in part, due to a delay or reduction in the expression of these genes. Further investigation revealed a decreased responsiveness of the petals to ethylene. Petals from heat-treated and control flowers were exposed to 1 ppm ethylene for 0, 0.5, 1, 2, 4, 6, 12, and 32 hr. The heat-treated petals again showed a delay and a decrease in maximum ethylene production after exposure to ethylene. A delay in expression of ACC synthase and ACC oxidase was also observed. The beneficial effects of exposing carnation flowers to high temperatures, a delay in ethylene production, and reduced responsiveness to ethylene, suggest that heat treatments could be used for disinfestation of this crop.

scholarly journals Effect of Jasmonates Differed at Fruit Ripening Stages on 1-Aminocyclopropane-1-Carboxylate (ACC) Synthase and ACC Oxidase Gene Expression in Pears

2007 ◽  
Vol 132 (1) ◽  
pp. 120-125 ◽  
Author(s):  
Satoru Kondo ◽  
Hiroko Yamada ◽  
Sutthiwal Setha
Keyword(s):  
Jasmonic Acid ◽  
Ethylene Production ◽  
Messenger Rna ◽  
Untreated Control ◽  
Acc Oxidase ◽  
Acc Synthase ◽  
Mrna Levels ◽  
Gene Expressions ◽  
Oxidase Gene ◽  
Climacteric Stage

The effects of n-propyl dihydrojasmonate (PDJ), which is a jasmonic acid derivative, on 1-aminocyclopropane-1-carboxylate (ACC) synthase and ACC oxidase activities, their gene expressions, and ethylene productions in ‘La France’ pears (Pyrus communis L.) were investigated. The fruit was harvested 156 days after full bloom, stored at 4 °C for 15 days, ripened at 20 °C, and then dipped into 0.39 mm PDJ solution at the preclimacteric stage (0 day of ripening at 20 °C) or the climacteric stage (9 days of ripening at 20 °C). In the skin of the PDJ-treated fruit at the preclimacteric stage, the expressions of ACC synthase (ACS)1 and ACC oxidase (ACO)1 were higher than the expressions of those in the untreated control. Ethylene production also increased in the PDJ-treated fruit. In contrast, the accumulation of the ACS1 messenger RNA (mRNA) levels in the skin and an increase of ethylene production were observed in the untreated control fruit at the climacteric stage, although the levels of mRNAs hybridized with ACO1 were not different between the PDJ-treated fruit and untreated control. The endogenous jasmonic acid levels in the skin increased in the PDJ-treated fruit regardless of the application times of PDJ. These results indicate that ACS1 may be an ACC synthase gene that is induced by jasmonates in pears, and that system 2 ethylene may be regulated by jasmonates.

scholarly journals Pawpaw [Asimina triloba (L.) Dunal] Fruit Ripening. I. Ethylene Biosynthesis and Production

2005 ◽  
Vol 130 (4) ◽  
pp. 638-642 ◽  
Author(s):  
Rumphan Koslanund ◽  
Douglas D. Archbold ◽  
Kirk W. Pomper
Keyword(s):  
Ethylene Production ◽  
Acc Oxidase ◽  
Acc Synthase ◽  
Weight Basis ◽  
Rapid Decline ◽  
Fruit Firmness ◽  
Fresh Weight ◽  
Fresh Weight Basis ◽  
Ripening Process ◽  
Acc Content

Pawpaw fruit ethylene production, 1-aminocyclopropane-1-carboxylic acid (ACC) synthase (ACS) and ACC oxidase (ACO) activities, and tissue content of the ethylene precursor ACC and conjugate malonyl-ACC (MACC) were measured during postharvest ripening. Fruit were harvested near the advent of the ripening process and were ripened at room temperature. The fruit displayed increases in ethylene production and respiration rate during ripening with maxima for both 3 days after harvest. Mean ethylene maxima on a fresh weight basis were 4.7 and 7.6 μg·kg-1·h-1 and mean respiratory (CO2 production) maxima on a fresh weight basis were 220 and 239 mg·kg-1·h-1 in 1999 and 2001, respectively. The increase in ethylene evolution coincided with an increase in respiration and a rapid decline in fruit firmness. Internal and external fruit firmness declined in a parallel manner. The ethylene climacteric peak occurred after the greatest decline in fruit firmness, indicating that low levels of ethylene may be sufficient to initiate the ripening process. The ethylene climacteric peak also coincided with the highest activities of both ACS and ACO as well as the maximum tissue ACC content. As ACC content increased, MACC content declined, suggesting a regulation of ethylene production via free ACC levels by malonylation of ACC. Thus, the climacteric development of ethylene production may be regulated by an increase of ACS activity and a decrease in ACC malonyltransferase activity, making more free ACC available for the production of ethylene by increased activity of ACO.

Ripening of 'Red Rosa' plums: effect of ethylene and 1-methylcyclopropene

2001 ◽  
Vol 28 (10) ◽  
pp. 1039 ◽  
Author(s):  
Li Dong ◽  
Hong-Wei Zhou ◽  
Liliane Sonego ◽  
Amnon Lers ◽  
Susan Lurie
Keyword(s):  
Ethylene Production ◽  
Acc Oxidase ◽  
Acc Synthase ◽  
Fruit Softening ◽  
Respiration Rates ◽  
Control Fruit ◽  
C Storage ◽  
Pectin Esterase ◽  
And Control

‘Red Rosa’, a Japanese type plum, was treated with 0.1 ppm 1-methylcyclopropene (1-MCP) for 20 h at 20˚C at harvest and then held at 20˚C for ripening together with untreated fruit, or placed at 0˚C storage for 5 weeks. Another batch of plums were exposed to 15 ppm ethylene during storage at 0˚C. Fruits ripening directly after 1-MCP treatment had lower ethylene production and softened more slowly than untreated fruits. Following storage, both the ethylene-treated and 1-MCP-treated fruits were low in ethylene production and softened more slowly than untreated fruits. They also showed lower exo-polygalacturonase (exo-PG) and endo-glucanase (EGase) activities. Respiration rates, pectin esterase (PE) and endo-PG activities were similar in 1-MCP-treated and control fruits. Cell wall enzyme activities were different amongst the treatments, but did not correlate with the differences in fruit softening. 1-Aminocyclopropane–1-carboxylic acid (ACC) oxidase (ACO) activity was highest in ethylene treated fruit during ripening after storage, while the mRNA abundance was highest in control fruit at removal from storage. ACC synthase (ACS) activity was higher in control and 1-MCP-treated fruit than in ethylene-treated during ripening after storage, and message abundance was highest at removal from storage in control fruit. ACC content was highest in fruits at removal from storage. The results are discussed in terms of the role of ethylene in ripening of ‘Red Rosa’ plums.

Alleviation of Thermoinhibition in Chickpea Seeds by Putrescine Involves the Ethylene Pathway

1996 ◽  
Vol 23 (4) ◽  
pp. 479 ◽  
Author(s):  
M Gallardo ◽  
I Sanchez-Calle ◽  
PMD Rueda ◽  
AJ Matilla
Keyword(s):  
Molecular Weight ◽  
Carboxylic Acid ◽  
Cicer Arietinum ◽  
Ethylene Production ◽  
Acc Oxidase ◽  
Sharp Decrease ◽  
Acc Synthase ◽  
Cicer Arietinum L ◽  
Adenosyl Methionine ◽  
Stimulation Of

Germination of chickpea (Cicer arietinum L.) was inhibited by supraoptimal temperatures of 30 or 35�C, but the inhibition was alleviated by a relatively low concentration (1 mM) of putrescine (Put). This allevation may be due to (a) stimulation of the 1-aminocyclopropane-1-carboxylate (ACC) synthase and ACC oxidase activities; (b) increased levels of ACC and decreased levels of 1-(malonylamino)cyclopropane-1-carboxylic acid (MACC); or (c) strongly increased ethylene production. Put at 10 mM did not alleviate thermoinhibition, although, as with Put at 1 mM, it did inhibit adenosyl-methionine (AdoMet) decarboxylase. Alleviation conditions resulted in: (a) an induced accumulation of free Put (S) and Put conjugated to substances of low (HS) and high (HP) molecular weight; (b) a decrease in spermidine (Spd) and spermine (Spm) (S and HP); and (c) no alteration in the levels of Spd and Spm (HS) with respect to the absence of Put (1 mM) at 30�C. In the presence of Put (10 mM), increased accumulation of Put (S, HS and HP) was detected, but with a sharp decrease of Spd and Spm (S and HS).

Effects of Exogenous Ethylene on AC and Rin Tomato Fruit

2014 ◽  
Vol 1033-1034 ◽  
pp. 677-680
Author(s):  
Ling Li ◽  
Hai Xue Liu ◽  
Yong Bo Peng ◽  
Shi Li ◽  
Tie Ling Liu
Keyword(s):  
Respiration Rate ◽  
Ethylene Production ◽  
Tomato Fruit ◽  
Acc Oxidase ◽  
Acc Synthase ◽  
Ethylene Biosynthesis ◽  
Flesh Firmness ◽  
Ethephon Treatment ◽  
Production Increase ◽  
Exogenous Ethylene

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.

Sign in / Sign up

Export Citation Format

Share Document