Inulin and oligofructose belong to a class of carbohydrates known as fructans. The main sources of inulin and oligofructose that are used in the food industry are chicory and Jerusalem artichoke. Inulin and oligofructose are considered as functional food ingredients since they affect the physiological and biochemical processes in rats and human beings, resulting in better health and reduction in the risk of many diseases. Experimental studies have shown their use as bifidogenic agents, stimulating the immune system of the body, decreasing the pathogenic bacteria in the intestine, relieving constipation, decreasing the risk of osteoporosis by increasing mineral absorption, especially of calcium, reducing the risk of atherosclerosis by lowering the synthesis of triglycerides and fatty acids in the liver and decreasing their level in serum. These fructans modulate the hormonal level of insulin and glucagon, thereby regulating carbohydrate and lipid metabolism by lowering the blood glucose levels; they are also effective in lowering the blood urea and uric acid levels, thereby maintaining the nitrogen balance. Inulin and oligofructose also reduce the incidence of colon cancer. The biochemical basis of these beneficial effects of inulin and oligofructose have been discussed. Oligofructose are non cariogenic as they are not used by Streptococcus mutans to form acids and insoluble glucans that are the main culprits in dental caries. Because of the large number of health promoting functions of inulin and oligofructose, these have wide applications in various types of foods like confectionery, fruit preparations, milk desserts, yogurt and fresh cheese, baked goods, chocolate, ice cream and sauces. Inulin can also be used for the preparation of fructose syrups.

Sucrose is required for plant growth and development. The sugar status of plant cells is sensed by sensor proteins. The signal generated by signal transduction cascades, which could involve mitogen-activated protein kinases, protein phosphatases, Ca 2+ and calmodulins, results in appropriate gene expression. A variety of genes are either induced or repressed depending upon the status of soluble sugars. Abiotic stresses to plants result in major alterations in sugar status and hence affect the expression of various genes by down- and up-regulating their expression. Hexokinase-dependent and hexokinase-independent pathways are involved in sugar sensing. Sucrose also acts as a signal molecule as it affects the activity of a proton-sucrose symporter. The sucrose trans-porter acts as a sucrose sensor and is involved in phloem loading. Fructokinase may represent an additional sensor that bypasses hexokinase phosphorylation especially when sucrose synthase is dominant. Mutants isolated on the basis of response of germination and seedling growth to sugars and reporter-based screening protocols are being used to study the response of altered sugar status on gene expression. Common cis-acting elements in sugar signalling pathways have been identified. Transgenic plants with elevated levels of sugars/sugar alcohols like fructans, raffinose series oligosaccharides, trehalose and mannitol are tolerant to different stresses but have usually impaired growth. Efforts need to be made to have transgenic plants in which abiotic stress responsive genes are expressed only at the time of adverse environmental conditions instead of being constitutively synthesized.

During the recent decades, awareness towards the role of essential fatty acids in human health and disease prevention has been unremittingly increasing among people. Fish, fish oils and some vegetable oils are rich sources of essential fatty acids. Many studies have positively correlated essential fatty acids with reduction of cardiovascular morbidity and mortality, infant development, cancer prevention, optimal brain and vision functioning, arthritis, hypertension, diabetes mellitus and neurological/neuropsychiatric disorders. Beneficial effects may be mediated through several different mechanisms, including alteration in cell membrane composition, gene expression or eicosanoid production. However, the mechanisms whereby essential fatty acids affect gene expression are complex and involve multiple processes. Further understanding of the molecular aspects of essential fatty acids will be the key to devising novel approaches to the treatment and prevention of many diseases.

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The number of seeds and seed yield per plant were higher in chickpea crops raised from water and mannitol (4 %) primed seeds in comparison with the control non-primed crops. In primed plants, an enhanced acid invertase activity in the apical part of the main stem and the part immediately below it at 100 and 130 days after sowing (DAS) might result in an increased availability of hexoses to these plant parts. In addition, decreased acid invertase activity at the point of initiation of branches and in the internodes of stem observed in primed plants indicated restricted hydrolysis of sucrose during its transport through the stem, resulting in its more supply to the actively growing sinks. The activities of sucrose-cleaving enzymes, i.e. invertase and sucrose synthase (SS) in podwall of primed plants were higher at 110 DAS. At 140 DAS, a stage of rapid seed filling, increased activities of SS and sucrose phosphate synthase (SPS) were observed in seeds of primed plants. Increased SPS activity in seeds of primed crop could meet the increased assimilate requirements of the developing seeds. Higher activity of SS in seeds of primed crop may facilitate seed filling. These data suggest that enzymes of sucrose metabolism play an important role in increasing the yield of chickpea crops raised from primed seeds.