scholarly journals Dormancy breakage of Stylosanthes humilis seeds by aluminium

2010 ◽  
Vol 20 (3) ◽  
pp. 145-152 ◽  
Author(s):  
Dimas M. Ribeiro ◽  
Ana M. Mapeli ◽  
Marcelo A.G. Carnelossi ◽  
Carla A. Delatorre ◽  
Raimundo S. Barros
Keyword(s):  
Ethylene Production ◽  
Methyl Viologen ◽  
Acc Oxidase ◽  
Low Ph ◽  
Sodium Selenate ◽  
Antioxidant Compounds ◽  
Stylosanthes Humilis ◽  
Physiological Dormancy ◽  
Townsville Stylo ◽  
Low Activity

AbstractPhysiological dormancy of scarified seeds of Townsville stylo (Stylosanthes humilis HBK) was released by acidic aluminium (Al3+) solution. Antiethylenic substances inhibited germination of low-pH-stimulated dormant seeds, with a correspondingly low ethylene production and low activity of 1-aminocyclopropane-1-carboxylate (ACC) oxidase in seeds. On the other hand, antiethylenic substances did not decrease the germination of Al3+-stimulated seeds, but ACC oxidase activity and ethylene production by the seeds was decreased to a large extent. These data provide evidence that dormancy breakage by Al3+ differs from that caused by low pH and is not associated with ethylene production. Similarly to Al3+ action, methyl viologen (MV), a reactive oxygen species-generating compound, broke dormancy of Townsville stylo seeds. Sodium selenate and N-acetyl cysteine, antioxidant compounds, largely decreased germination of MV- and Al3+-stimulated dormant seeds. Altogether these data point to oxidative radicals constituting key molecules in the chain of events triggered by Al3+ leading to dormancy breakage.

scholarly journals Effect of the seed coat on dormancy and germination in Stylosanthes humilis H. B. K. Seeds

2017 ◽  
Vol 39 (2) ◽  
pp. 114-122 ◽  
Author(s):  
Izabel de Souza Chaves ◽  
Nilo Cesar Queiroga Silva ◽  
Dimas Mendes Ribeiro
Keyword(s):  
Seed Coat ◽  
Room Temperature ◽  
Low Ph ◽  
Physical Dormancy ◽  
Hard Seed ◽  
Stylosanthes Humilis ◽  
Physiological Dormancy ◽  
Radicle Protrusion ◽  
Townsville Stylo ◽  
Hard Seed Coat

Abstract: Seed of Townsville stylo (Stylosanthes humilis H.B.K.) is known to exhibit a hard seed coat and when freshly harvested also show a physiological dormancy, however, the nature of the co-actions between seed coat and embryo growth that determine dormancy is poorly understood. In this study, physical dormancy of Townsville stylo seeds was not reduced during natural ageing at room temperature, in contrast to the physiological dormancy, which is gradually overcome during after-ripening. Furthermore, the permeability of seed coat was affected by scarification treatments as well as by low-pH solutions. Together, these data indicate that physical dormancy overcome of seed is prerequisite for radicle protrusion and physiological dormancy of Townsville stylo seeds contribute to its timing.

Sensitivity to ethylene as a major component in the germination of seeds of Stylosanthes humilis

2006 ◽  
Vol 16 (1) ◽  
pp. 37-45 ◽  
Author(s):  
Dimas Mendes Ribeiro ◽  
Raimundo Santos Barros
Keyword(s):  
Complete Inhibition ◽  
Free Atmosphere ◽  
Low Concentrations ◽  
Stylosanthes Humilis ◽  
Physiological Dormancy ◽  
Townsville Stylo ◽  
Short Time

Physiological dormancy of scarified seeds of Townsville stylo (Stylosanthes humilisH.B.K.) is broken by ethylene. When the biosynthesis of this gas was impaired by 2-aminoethoxyvinylglycine (AVG) plus Co2+, the response to ethylene at very low concentrations was appreciable in non-dormant seeds and nil in the dormant ones. Complete inhibition of germination of non-dormant seeds occurred only when they were treated with AVG plus Co2+under an ethylene-free atmosphere, a condition in which no trace of the gas in the atmosphere of Erlenmeyer flasks could be detected. Injection of ethylene into that system triggered germination of both dormant and non-dormant seeds, demonstrating a requirement for the gas. Non-dormant seeds were at least 50-fold more sensitive to ethylene than the dormant ones. Perception of ethylene occurred within a very short time (at most 15 min), since exposure of both dormant and non-dormant seeds to the gas, at a steeply declining concentration, sufficed to cause substantial germination.

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 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 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 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.

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