Flowers ethylene

On photolysing cyclobutanone and cyclopentanone in the presence of excess ethylene. Flowers and Frey reported the formation of long-chain aliphatic and cyclic alkanes, considering it as a confirmation of the biradical mechanism. However on repeating these experiments,other workers did not observe the formation of the products reported by Flow.r and Frey, not even in the presence of 1 atm of C2H4. 

Forest systems also act as sources of CO2 when controlled or uncontrolled burning and decay of litter occur. In addition, release of ethylene occurs during the flowering of various species. One additional form of emission to the atmosphere is the release of pollen grains. Pollen is essential to the reproductive cycle of most forest systems but becomes a human health hazard for individuals susceptible to hay fever. The contribution of sulfur from forests in the form of dimethyl sulfide is considered to be about 10-25% of the total amount released by soils and vegetation (12). 

The quantity of these materials is relatively small compared with the amount of waste high-density poly(ethylene) produced each year. Containers made from HDPE are widely used for detergents, oil, and antifreeze, and enormous amounts of material are used in disposable applications aimually. In principle recycled poly(ethylene) could be used for drain pipes, flower pots, dustbins, and plastic crates. The problem remains, however, that economics do not favour recycling of these polymers and in the absence of Government intervention little or nothing can be done to alter commercial attitudes towards recycling. 

In spite of the often constitutive activity of AGO in the majority of plant tissues, an increase in its activity may regulate ethylene production especially associated with ripening and senescence of leaves, fruits, and flowers (see Sections 5.04.2.3 and 5.04.4.2.3, and Figure 3). 

In orchid flower Phalaenopsis sp.), ethylene synthesis is regulated hy the coordinated expression of three... 

Most species of angiosperms produce hermaphroditic flowers. The unisexuality in some plants most often results from developmentally programmed abortion or selective reduction in sex organ primordia. In dicots, higher levels of auxins, cytokinins, and ethylene usually correlate with female sex expression and in most of them the femaleness is mainly promoted by ethylene. ... 

Ethylene is the major feminizing hormone in most cucurbits showing a wide range of sex phenotypes with some exception of watermelon in which a steady increase in ACS isozymes transcript level in male flowers compared with female flowers has been reported. ... 

Despite the potent influence of ethylene on the whole plant development, most often it has been recognized as a fruit-ripening and senescence-associated hormone. With respect to the gaseous nature of this hormone, the knowledge about ethylene sensitivity of fruit and flower is necessary to predict the effects of their mixed storage and transport and the usefulness of anti-ethylene treatments. Such commercial implications of ethylene have made it a topic of investigation for decades. 

Ethylene-dependent mechanism terminates flower life after successful pollination as a way to benefit survival of the species. Usually, in species with short-lived flowers, such an ethylene-dependent termination apparently is not beneficial as the life of individual flowers is short anyway. Similarly, in species with numerous flowers in one flower head in which continuous visits of pollinators are required, ethylene-dependent termination is not beneficial. ... 

The discovery of ethylene as a plant growth substance followed from the observation in Germany that leakage of gas used in street lighting was associated with the defoliation of trees. Subsequent research demonstrated the active component as ethylene, which was then implicated in the endogenous acceleration of ripening, the promotion of flowering and sex determination in addition to abscission of plant parts. 

Yamasaki, S. Fujii, N. Takahashi, H. The ethylene-regulated expression of CS-ETR2 and CS-ERS genes in cucumber plants and their possible involvement with sex expression in flowers. Plant Cell Physiol., 41, 608-616 (2000)... 

Dervinis, C. Clark, D.G. Barrett, J.E. Nell, T.A. Effect of pollination and exogenous ethylene on accumulation of ETRl homologue transcripts during flower petal abscission in geranium (Pelargonium x hortorum L.H. Bailey). Plant Mol. Biol., 42, 847-856 (2000)... 

Synthesis of ethylene, a gaseous plant hormone involved in fruit ripening and flower senescence. 

Silver salts, particularly AgN03 and [Ag(S203)2]3, are used to preserve cut flowers.117 The eSect is associated with the inhibition of ethylene production in the flower. 

Ethylene plays an important role in a number of plant developmental processes, including senescence and abscission of leaves and flowers, responses to wounding, and the ripening of climacteric fruits (Abeles, 1973). In each case ethylene is produced from methionine (Fig. 1). The two enzymes specific to the pathway, ACC synthase and ethylene forming enzyme, increase in activity in response to wounding and during ripening,... 

Injury by ethylene (ethene) typically develops slowly over a considerable time (chronic injury) and is expressed as distortion of growth, epinasty, chlorosis, defoliation, and excessive drop of blossoms or fruits. Symptoms of acute injury on orchid blossoms (dry sepal) may be produced by six-hour exposure to 0.1 ppm when the flower bud is in the most susceptible stage. 

Silver ions923 and 2,5-norbornadiene (NBD)924 are well known as effective inhibitors of ethylene action. Silver, applied in the form of thiosulfate (silver thiosulfate (STS)), is a very effective inhibitor of ethylene action. It has been used with much success on cut flowers and potted plants. But as it is a heavy metal it cannot be used on food and feed, and is harmful to environment. As NBD requires continuous exposure and a high concentration, and has a strong odor, it also cannot be used on cut flowers and food. Furthermore, both compounds are toxic for plant growth in high concentration. 

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