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This report summarizes the recent research efforts to estimate the dietary intakes of both boron and silicon in the Chinese adult male population. In addition, the primary sources of boron in the Chinese diet were identified and compared to the previously identified primary dietary sources of boron in diets from the United States, Germany, Great Britain, Mexico, Kenya, and Egypt. [ABSTRACT FROM AUTHOR]

Boron, an element ubiquitous in the earth's crust can be found in most soil types as well as in fresh and salt water, consequently, boron is a natural constituent in the human diet (Nemodruk and Karalova, 1969, Meacham and Hunt, 1998). In a typical adult daily intakes of boron were measured to be approximately 1 mg/day (Meacham and Hunt, 1998, Rainey et al. 1999). Boron is considered an essential micronutrient for higher plants; however, the most recent US dietary recommendations concluded that insufficient evidence existed to consider boron an essential micronutrient for humans (Warrington, 1923, Loomis and Durst, 1992, IOM, 2001). However, evidence does exist that indicates boron plays a beneficial role in some physiological processes of various animal species and measurable responses to adjusted boron intakes in humans have been observed (Rowe and Echkert, 1999, Nielsen, 1998). [ABSTRACT FROM AUTHOR]

There were some reports containing information on micronutrients in citrus area (Kausar et al. 1979; Rashid et al. 1991). Upon looking the details, it was found that existing information were limited and unsystematic. The samples were collected disregarding the time and age of plant tissues during sampling which is very important aspect. To establish nutrients deficiency in fruit plants, the age of leaves taken from bearing and non-bearing branches are extremely important. These aspects were mostly lacking from the existing information. Keeping in view the previous work done in Pakistan, more appropriate efforts have been made in this study to investigate soil and plant micronutrients status of citrus growing area on high-pH calcareous soils. [ABSTRACT FROM AUTHOR]

Boron is distributed in nature very widely. The average content of boron in the earth's crust is 1×10-3%. More than 150 boron minerals have been found, but only about ten of them are currently in use. The chemical composition of boron minerals is divided into three types: borosilicate minerals, boro-alumino-silicate minerals and borate minerals (including those containing water and anhydrous borate minerals). [ABSTRACT FROM AUTHOR]

The Pothwar plateau in Pakistan (Fig. 1; latitude 32° 10' to 34° 9' N; longitude 71° 10' to 73° 55' E) is part of the great Indo-Gangetic synclinorium, separated from it, and elevated, at the end of the Tertiary Period. The plateau spans over 1.82 million hectare (Mha) and constitutes a major rainfed tract in the north of Punjab province, Pakistan (Fig. 2). It is situated in the north of Salt Range, in-between rivers Jehlum and Indus. Its climate is semi-arid to sub-humid continental. Rainfall pattern in the plateau is bi-model; the maximum being in late summer and winter-spring (Fig. 3). [ABSTRACT FROM AUTHOR]

Mango (Mangifera indica. L) is grown in 1.1 m ha in India in different climatic zones ranging from humid tropics receiving 2500 mm annual rainfall to semi arid tropics (600-900mm rainfall) and subtropics (800-1000mm rainfall). It is also grown in soils widely varying in its physico chemical properties. The pH of mango orchards range from a low of 4.5-5.2 in Konkan, Maharashtra to 7.2 to 8.1 in Uttar Pradesh and Chittor, Andhra Pradesh and accordingly it is affected by different types of macro and micronutrient disorders based on soil properties Boron deficiency is one of the important micronutrient disorders affecting mango both in high rainfall areas (Edward Raja et al 2005) and in semi arid tropics and average productivity is low at 6-7 t ha-1. [ABSTRACT FROM AUTHOR]

Boron is an essential micronutrient element required for the normal growth of plants. The range between boron deficiency and toxicity symptoms in plants is typically narrow, in the range of 0.028 to 0.093 mmol/L for sensitive crops and 0.37 to 1.39 mmol/L for tolerant crops (Goldberg, 1997). Much work has been done on plant availability of boron and physico-chemistry of boron in soil, but generally not in combination. Availability of boron to plants is affected by a variety of soil factors including soil solution pH, soil texture, soil moisture, temperature, oxide content, carbonate content, organic matter content, and clay mineralogy (Goldberg et al. 2000). However, these soil properties are functions of the physico-chemistry of soils, so that determination of relationships between plant availability of boron and the physico-chemical properties of boron in soils has still tremendous interest for us. This article summarizes results about plant availability of B, physico-chemical properties of soil B, chemical behavior of common B soil minerals and their relationships. [ABSTRACT FROM AUTHOR]

Plants vary in their B requirement but the range between deficient and toxic soil solution concentration of B is very narrow than for any other nutrient element. In arid and semi arid regions, B toxicity results from high levels of B in soils and from addition of boron via irrigation water. However, B deficiency is of great concern in areas receiving heavy rainfall. Compared with other micronutrients, chemistry of B in soils is very simple. Boron doesn't undergo oxidation-reduction reactions or volatilization reaction in soils. Boron containing minerals are either insoluble (Tourmaline) or very soluble (Hydrated B minerals) and generally do not control the solubility of B in soil solution (Goldberg et al. 1993). Boron concentration in the soil solution is generally controlled by B adsorption reaction as is the amount of water soluble B available for plant uptake. [ABSTRACT FROM AUTHOR]

Boron is an essential micronutrient element required for plant growth. Boron deficiency is wide-spread in crop plants throughout the world especially in coarse-textured soils in humid areas. Boron toxicity can also occur, especially in arid regions under irrigation. Plants respond directly to the B concentration in soil solution and only indirectly to the amount of B attached to soil surfaces (Keren et al. 1985). Therefore, the soil adsorption complex acts as both a source and a sink for dissolved B and can mitigate phytotoxic soil solution B concentrations. [ABSTRACT FROM AUTHOR]

The aim of this paper is describe how boron was identified as an anticancer agent for prostate cancer and how research using human prostate cells identified a biochemical mechanism that may explain many of the diverse effects reported for the element in plants and animals. At physiological pH, boric acid binds to NAD+, a coenzyme in metabolism and substrate for an enzyme in the NAD+ cADPR system of calcium signaling. [ABSTRACT FROM AUTHOR]

Studies by several different research groups using different experimental animals indicate that nutritional amounts of boron beneficially affect bone histomorphological and gross physical characteristics. One of the first studies suggesting that boron is essential for higher animals found that boron improved bone calcification in chicks fed a diet deficient but not completely lacking in vitamin D (Hunt and Nielsen, 1981). At the microscopic level, boron deprivation (0.465 mg/kg diet) exacerbated the distortion of marrow sprouts (location of calcified scaffold erosion and new bone formation) and the delay in initiation of cartilage calcification in bones during marginal vitamin D deficiency (Hunt, 1996). [ABSTRACT FROM AUTHOR]

Research in a number of animal species indicates that boron is of nutritional importance and findings continue to support the concept that boron is an essential trace element (Nielsen, 2002). Recent studies indicate that dietary boron affects various immune processes (Hunt and Idso, 1999; Armstrong et al. 2001). The immune system consists of an array of interrelated components that function to protect the host animal against foreign materials, including pathogenic organisms. The immune system can be divided into innate and adaptive or acquired immunity. Innate immunity is non-specific in regard to foreign organisms that it will attack, and consists of physical barriers to organisms such as skin and internal mucous membranes, as well as components that are induced by exposure to foreign material such as phagocytic cells and complement. The innate immune system responds rapidly to invasion of the host by foreign materials; however, its effect is of relatively short duration. The adaptive immune system develops slower in response to attack by various invaders, but is more substained and leads to proliferation of lymphocytes and synthesis of antibodies specifically directed at the organism invading the host. In addition, the adaptive immune system also results in immunological memory that provides long-term immunity against future attacks by the same organism. This paper will review research indicating a role for boron in immune function. [ABSTRACT FROM AUTHOR]

Boron has served essential function since the early evolution of life as evidenced by the essentiality of the element for the heterocystous Cyanobacteria, predominant organisms during the Middle Pre-Cambrian Period (Bonilla et al. 1990). The element boron is essential for at least some organisms in all phylogenetic kingdoms. The first natural biomolecules found to contain boron were antibiotics produced by species in Eubacteria (Bonilla et al. 1990; Chen et al. 1981; Hutter et al. 1967; Sato et al. 1978; Schummer et al. 1994). Boron is required for specific brown algae and diatoms in Stramenopila and for all higher plants in Viridiplantae (Lovatt and Dugger 1984). Specific fungi have a demonstrated physiological response to boron (Bennett et al. 1999), an important finding because species in the kingdom Fungi are thought to share a common ancestor with animals exclusive of plants (Carney and Bowen 2004). This review summarizes the evidence that boron satisfies the criteria for essentiality in humans and higher animals (Expert Consultation WHO/FAO/IAEA 1996; Frieden 1984; Mertz 1970; Underwood and Mertz 1987): 1) it reacts with biological material or forms chelates; 2) it is present in healthy tissues of different animals at comparable concentrations; 3) toxicity results only at relatively high intakes; 4) tissue concentrations during short term variations in intake are maintained by homeostatic mechanisms; 5) depletion prevents growth and completion of the life cycle; 6) depletion consistently results in reduction of a physiologically important function; and 7) when an integral part of an organic structure, depletion causes reduction in performance of a vital function. [ABSTRACT FROM AUTHOR]