THE FORMATION OF SEEDS AND FRUITS

The Formation of Seeds and Fruits. — Germination. — The Vascular System. 

Shoot and root structures are already present in the embryo of seeds. Thus the essential processes of differentiation have already been realized. In germination and subsequent processes, the organ structures present in the embryo are simply differentiated further. What interests us is how an embryo with its organ structures develops in the first place. That is why we shall now discuss a few of the details of the formation of seeds and fruit before coming to the section on germination. 

The embryo is already invested with all of the essential organs of the plant. Consequently, the development of the embryo is a quite decisive stage of development. As it proceeds, it is tightly coupled with the formation of seeds and, in certain circumstances, of fruit and should thus be discussed in this context. 

The general effect of phosphates is to favour the formation and ripening of seeds, and in this respect it acts in the opposite direction to combined nitrogen, which favours the growth of stalks or straw at the expense of seed or fruit. 

Differentiation can be defined as the process of specialisation in terms of shape and function. An example is cell differentiation in plants, animals and humans a young cell, which is initially multifunctional, gradually acquires one specific function and shape. Specialisation is a refinement that is expressed in terms of shape, scent and colour. For example, fruits ripen, leaves change colour in the autumn, the growth of a shoot ends in a terminal bud and seeds become dormant. The primary components are converted into secondary components such as phenols, vitamins, aromas, wax, and so on. Thus differentiation in this context has a broader meaning than only the formation of a new plant organ . 

Principle The observation of the rate and success of fertilization on the formation of fruits and seeds in the plant was used. The pistil stigma is treated with allelochemical and then pollen is added or pistil is not treated, but pollen treated with allelochemical is added on the pistil stigma (Roshchina, 2001 a, b). 

Plant waxes are concentrated on leaves and leaf sheaths and on fruit skins, or in some exceptional cases in the seeds of plants. Most vegetable waxes contain predominantly wax esters plus a variety of other lipid materials, which affect the degree of saturation and other properties of the wax derived from different sources. Most use has been made of plant waxes in the cosmetic sector, but there is increasing interest in the use of plant-derived sterols as dietary supplements to reduce cholesterol formation. 

Celery Seed Oil occurs as a yellow to green-brown liquid with a pleasant, aromatic odor. It is the volatile oil obtained by steam distillation of the fruit or seed of Apium graveolens L. It is soluble in most fixed oils with the formation of a flocculent precipitate, and in mineral oil with turbidity. It is partly soluble in propylene glycol, but it is insoluble in glycerin. 

Several limonoids are known to be bitter principles of citrus (Rutaceae). A typical example is limonin. Although fresh juice does not elicit a bitter taste, sometimes it becomes bitter after heating or storage. This is explained by the formation of bitter-tasting limonin by deglycosylation and further cyclization from limonin glucoside, which is present in citrus fruit tissue and seeds and does not exhibit bitterness.146 Recently, it was reported that limonin had antitumor activity.147 Besides limonin, nomilin and obakunone, which are considered to be... 

The first key step in the biosynthesis of tropane alkaloids is the formation of the intermediate putrescine. Polyamines and, therefore putrescine, are found in plant cells and are implicated in growth, root, fruit and flower development, and in different stress phenomena. It is well known that plants synthesize polyamines from ornithine and arginine, unlike other eukaryotes like mammals, which only synthesize polyamines from ornithine. In plants putrescine is synthesized directly from ornithine, a reaction catalysed by ornithine decarboxylase (ODC, EC 4.1.1.17) and indirectly from arginine via agmatine catalysed by arginine decarboxylase (ADC, EC 4.1.1.19), Fig. (1). In Arabidopsis, it is known that the adc gene is required for the production of polyamines that are essential for normal seed development [103]. 

The browning of plant tissues which occurs during the formation of the coats of the seeds, fruits and vegetables, in barks, and in the spores of fungi is associated with the oxidation mainly, of various phenolic substances. However, daphnetin, esculetin and some other coumarin derivatives have also been included in the numerous substrates for the browning enzymes responsible for these processes [166—173]. The enzymes catalysing these changes are oxidases and phenolases, and perhaps they also participate in the synthesis and biotransformation of the various coumarins [174—177]. 

In the sixteenth and early seventeenth centuries, the distillation and extraction of plant and animal materials were the characteristic chemical operations of pharmacy. The focus of chemical-pharmaceutical practice was on the extraction of oils and juices and on the distillation of aqueous and oily substances from plants or vegetable materials such as herbs, blossoms, fruits, seeds, woods, resins, and balsams. However, in the sixteenth century Paracelsus and his followers began to use more frequently minerals as a source of medicines in addition to vegetable and animal substances. What was at first only a sporadic production of new chemical prepara-tions eventually induced a fundamental change in pharmacy. During the seventeenth century, preparations of mineral acids and salts surfaced as an important sector of chemical-pharmaceutical practice. This new commercial chemical practice spurred a process of reflection that contributed to the formation of the modem concept of the chemical compound. 

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