Morphological alterations of pea (Pisum sativum cv. Sparkle) arbuscular mycorrhizas as a result of exogenous ethylene treatment

Mycorrhiza ◽  
2001 ◽  
Vol 11 (3) ◽  
pp. 137-143 ◽  
Author(s):  
Ryan D. Geil ◽  
Larry R. Peterson ◽  
Frédérique C. Guinel
1971 ◽  
Vol 24 (4) ◽  
pp. 885 ◽  
Author(s):  
M Vendrell ◽  
WB Mcglasson

A temporary ethylene treatment, sufficient to stimulate ripening in banana fruit tissue, partly suppresses endogenous ethylene production and the evolution of ethylene from methionine. The production of endogenous ethylene does not return to rates normal for naturally ripening fruit after the exogenous ethylene is removed. The extent of inhibition is related to the concentration of applied ethylene up to 5-10 p.p.m., and to the duration of treatment within the period 12 hI' to 3 days. Other characteristics of ripening appear to develop normally, except in the shorter treatments, where respiration shows a lower climacteric peak and chlorophyll breakdown is delayed.


HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 463f-463
Author(s):  
Guiwen Chene ◽  
Carlos Crisosto ◽  
David Garner

During the 1993 and 1994 seasons, the response of Kiwifruit (Actinidia deliciosa var. Hayward) flesh softening to exogenous ethylene applications was studied on fruit collected weekly from cold storage and directly from the vines. Fruit samples from both sources, were induced to ripen with and without ethylene preconditioning treatment (10 ppm, 24h at 0C). During the first 3 weeks of fruit collection, flesh firmness decreased and SSC accumulation increased faster in ethylene treated kiwifruit than in the untreated. After this period, when kiwifruit had close to 9 pounds flesh firmness, ethylene treated and untreated kiwifruit softened at the same rate. Ethylene treatment did not enhance kiwifruit CO2 and ethylene production except at the first harvest time. Furthermore, ethylene treated kiwifruit did not have higher respiration and ethylene rates than untreated kiwifruit when measured at 0, 5 and 20C.


1998 ◽  
Vol 123 (6) ◽  
pp. 1094-1101 ◽  
Author(s):  
Fernando Maul ◽  
Steven A. Sargent ◽  
Murat O. Balaban ◽  
Elizabeth A. Baldwin ◽  
Donald J. Huber ◽  
...  

The effect of physiological maturity at harvest on ripe tomato (Lycopersicon esculentum Mill.) volatile profiles was studied using ripening response time (in days) to 100 μL·L-1 exogenous ethylene treatment as a tool to separate immature-green from mature-green fruit. Electronic nose (EN) sensor array and gas chromatography (GC) analyses were used to document volatile profile changes in tomatoes that required a 1-, 3-, or 5-day ethylene treatment to reach the breaker stage. EN output analysis using multivariate discriminant and canonical analyses classified intact tomato and whole tomato homogenate samples that required 3 or 5 days of ethylene treatment as significantly different (P < 0.01) from those that required only 1 day. The GC aroma profiles from whole tomato homogenate showed that 1-day fruit had significantly higher levels (P < 0.05) of 1-penten-3-one, cis-3-hexenal, 6-methyl-5-hepten-2-one, 2-isobutylthiazole, and geranylacetone when compared to 5-day fruit. Analysis of excised tomato tissues showed that pericarp (including columnella) produced an average 219% greater concentration of the 16 aroma volatiles quantified by GC when compared to locular gel (442 and 203 μL·L-1, respectively). EN analysis concurred with GC by showing greater average Mahalanobis distance between pericarp tissue groupings when compared to locular gel groupings (78.25 and 12.33 units, respectively). Pericarp tissue from the 5-day ethylene treatment showed significantly lower levels of 1-penten-3-one, trans-2-heptenal, 6-methyl-5-hepten-2-one, 2-isobutylthiazole, geranylacetone, and β-ionone compared to the 1- and 3-day treatments, Similarly, locular gel from the 3- and 5-day ethylene treatments had significantly lower levels of 1-penten-3-one, 2-isobutylthiazole, and 1-nitro-2-phenylethane compared to 1-day samples. cis-3-Hexenol in locular gel was the only volatile compound that showed significantly higher levels with increasing ethylene treatment. EN analysis showed greater Mahalanobis distances between 1- and 3-day ethylene samples than between 3- and 5-day ethylene samples (32.09 and 12.90, 24.14 and 6.52, 116.31 and 65.04, and 15.74 and 13.28 units, for intact tomato, whole tomato, pericarp, and locular gel homogenate, respectively).


1995 ◽  
Author(s):  
William Woodson ◽  
Shimon Mayak ◽  
Haim Rabinowitch

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.


1992 ◽  
Vol 100 (4) ◽  
pp. 1759-1763 ◽  
Author(s):  
Kwang Hoe Lee ◽  
Thomas A. LaRue

2004 ◽  
Vol 129 (5) ◽  
pp. 752-759 ◽  
Author(s):  
Jiwon Jeong ◽  
Donald J. Huber

Pre-ripe `Booth 7' avocado (Persea americana Mill.) fruit, a cross of West Indian and Guatemalan strains, were treated with 0.9 μL·L-1 1-methylcyclopropene (1-MCP) for 12 hours at 20 °C. After storage for 18 days in air at 13 °C, at which time whole fruit firmness values averaged about 83 N, half of the 1-MCP-treated fruit were treated with 100 μL·L-1 ethylene for 12 hours and then transferred to 20 °C. 1-MCP delayed softening, and fruit treated with 1-MCP retained more green color than air-treated fruit when full ripe (firmness 10 to 15 N). 1-MCP affected the activities of pectinmethylesterase (EC 3.2.1.11), α-(EC 3.2.1.22) and β-galactosidases (EC 3.2.1.23), and endo-β-1,4-glucanase (EC 3.2.1.4). The appearance of polygalacturonase (EC 3.2.1.15) activity was completely suppressed in 1-MCP-treated fruit for up to 24 days, at which time the firmness of 1-MCP-treated fruit had declined nearly 80% compared with initial values. The effect of exogenous ethylene applied to partially ripened 1-MCP-treated fruit differed for different ripening parameters. Ethylene applied to mid-ripe avocado exerted no effect on the on-going rate or final extent of softening of 1-MCP-treated fruit, even though polygalacturonase and endo-1,4-β-glucanase activities increased in response to ethylene. β-galactosidase decreased in 1-MCP-treated fruit in response to ethylene treatment. 1-MCP delayed the increase in solubility and depolymerization of water- and CDTA (1,2-cyclohexylenedinitrilotetraacetic acid)-soluble polyuronides, likely due to reduced polygalacturonase activity. At the full-ripe stage, the levels of arabinose, galactose, glucose, mannose, rhamnose, and xylose associated with the CDTA-soluble polyuronide fraction were similar among all treatments. In contrast, the galactose levels of water-soluble polyuronides declined 40% and 17% in control and 1-MCP treated fruit, respectively. Hemicellulose neutral sugar composition was unaffected by 1-MCP or ethylene treatment. The data indicate that the capacity of avocado fruit to recover from 1-MCP-mediated suppression of ripening can be only partially amended through short-term ethylene application and differs significantly for different ripening parameters.


2016 ◽  
Vol 43 (5) ◽  
pp. 413 ◽  
Author(s):  
Juanxu Liu ◽  
Ji Zhao ◽  
Zhina Xiao ◽  
Xinlei Chang ◽  
Guoju Chen ◽  
...  

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.


Cells ◽  
2019 ◽  
Vol 8 (12) ◽  
pp. 1612 ◽  
Author(s):  
Yongchao Zhu ◽  
Ke Wang ◽  
Chunxia Wu ◽  
Yun Zhao ◽  
Xueren Yin ◽  
...  

Peach is prone to postharvest chilling injury (CI). Here it was found that exogenous ethylene alleviated CI, accompanied by an increased endogenous ethylene production. Ethylene treatment resulted in a moderately more rapid flesh softening as a result of stronger expression of genes encoding expansin and cell wall hydrolases, especially xylosidase and galactosidase. Ethylene treatment alleviated internal browning, accompanied by changes in expression of polyphenol oxidase, peroxidase and lipoxygenases. An enhanced content of phospholipids and glycerolipids and a reduced content of ceramide were observed in ethylene-treated fruit, and these were associated with up-regulation of lipid phosphate phosphatase, fatty acid alpha-hydroxylase, and golgi-localized nucleotide sugar transporter, as well as down-regulation of aminoalcohol phosphotransferases. Expression of two ethylene response factors (ERFs), ESE3 and ABR1, was highly correlated with that of genes involved in cell wall metabolism and lipid metabolism, respectively. Furthermore, the expression of these two ERFs was strongly regulated by ethylene treatment and the temperature changes during transfer of fruit into or out of cold storage. It is proposed that ERFs fulfill roles as crucial integrators between cell wall modifications and lipid metabolism involved in CI processes ameliorated by exogenous ethylene.


HortScience ◽  
1993 ◽  
Vol 28 (3) ◽  
pp. 201-203 ◽  
Author(s):  
Steven A. Altman ◽  
Theophanes Solomos

Continuous postharvest treatment of carnation flowers (Dianthus caryophyllus L. cv. Elliot's White) with 50 or 100 mM aminotriazole significantly extended useful vase life relative to flowers held in distilled H2O. No morphological changes symptomatic of floral senescence appeared in treated flowers until 12 to 15 days after harvest. The longevity of aminotriazole-treated flowers was extended to ≈18 days. The respiratory rate of aminotriazole-treated carnations was suppressed, and they exhibited no respiratory climacteric throughout the period of observation. The responsiveness of aminotriazole-treated flowers to exogenous ethylene appeared temporally regulated. Flowers treated with 50 mM aminotriazole for 2 days senesced in response to application of 10 μl exogenous ethylene/liter, whereas flowers treated for 24 days exhibited no morphological response to ethylene treatment. Chemical name used: 3-1H-amino-1,2,4-triazole-1-yl (aminotriazole).


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