Early Effects of Boron Deficiency on Indoleacetic Acid Oxidase Levels of Squash Root Tips

Bohnsack, Charles W.; Albert, Luke S.

doi:10.1104/pp.59.6.1047

Cited by 89 publications

(50 citation statements)

References 18 publications

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“…Available evidence demonstrates that boron is essential for the normal functioning of root apical meristems (1,3,6,9,15,16,24,31). However, little is known about the sensitivity of root cells in the elongation and differentiation zones to boron deprivation.…”

Section: Resultsmentioning

confidence: 99%

Synthesis, Salvage, and Catabolism of Uridine Nucleotides in Boron-Deficient Squash Roots

Lovatt¹,

Albert²,

Tremblay³

1981

Plant Physiol.

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Previous work has provided evidence that plants may require boron to maintain adequate levels of pynmidine nucleotides, suggesting that the state of boron deficiency may actually be one of pyrimidine starvation. Since the avaflability of pyrimidine nucleotides is influenced by their rates of synthesis, salvage, and catabolism, we compared these activities in the terminal 3 centimeters of roots excised from boron-deficient and -sufficient squash plants (Cscurbita pepo L. (7) and [14CJorotic acid (36) into RNA in borondeficient mung bean root apices and cotton ovules, respectively. These reports suggest that the utilization or the level of available purine or pyrimidine nucleotides, or both, is altered by boron deprivation.We were particularly interested in the observation (30) that plants growing in the absence of boron could be protected from developing boron-deficiency symptoms by adding a hydrolysate of yeast RNA to the nutrient solution. Work in our laboratory (2, 15, 16), and elsewhere (4, 5) tested the effects of both purine and pyrimidine bases on plant growth to determine which component(s) of the RNA hydrolysate afforded this protection. Intact plants and isolated organs cultured in the absence of boron were protected to varying degrees from developing boron deficiency symptoms when pyrimidine bases were added to the medium.This result was taken as evidence that the state of boron deficiency may, in fact, be a case of pyrimidine starvation. Such an interpretation was supported by the observations that both barbituric acid and 6-azauracil, known inhibitors of pyrimidine biosynthesis (13,25,26), produced symptoms identical with those of boron deprivation (2, 5, 16). Various investigators (5,(19)(20)(21)36) have suggested that boron deficiency results in impaired de novo biosynthesis of pyrimidine nucleotides. Such impairment could occur through either a loss in amount of one or more enzymes or enhanced sensitivity of the de novo pathway to end product inhibition. Starvation for pyrimidine nucleotides could also result from an inability of boron-deficient plants to salvage or reutilize pyrimidine bases or nucleosides, or from an acceleration of pyrimidine catabolism.In this communication, we report the results of a comparison of the capacity of roots from boron-sufficient (+B)3 and borondeficient (-B) squash plants (Cucurbita pepo L., cv. Early Prolific straightneck) to synthesize uridine nucleotides de novo. We also include an examination of the possibility that boron deprivation interferes with the mechanism regulating the de novo pathway through end product inhibition. In addition, since catabolism opposes de novo biosynthesis, we also assessed the capacity of +B and -B roots to catabolize uridine and uracil. Finally, we measured salvage activity for the reutilization of pyrimidines during these two states of boron nutrition.

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Section: Resultsmentioning

confidence: 99%

Synthesis, Salvage, and Catabolism of Uridine Nucleotides in Boron-Deficient Squash Roots

Lovatt¹,

Albert²,

Tremblay³

1981

Plant Physiol.

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“…Cell death may result from this with a concomitant synthesis of auxin (see Sheldrake's views in paragraph above). Although this hyperauxiny may induce IAA-oxidase, the activity of this enzyme complex is itself inhibited by o-diphenols (see Coke and Whittington, 1968;Hewitt and Smith, 1975;Bohnsack and Albert 1977).…”

Section: Boron In Relation To Hormone Metabolism and Peroxidasesmentioning

confidence: 99%

Boron, Lignification and the Origin of Vascular Plants‐a Unified Hypothesis

Lewis

1980

New Phytologist

174

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SUMMARYIt is proposed that the development of an essential role for boron was a prerequisite for the evolution of vascular from prevascular plants since there is a prima facie case that a primary role of boron concerns the biosynthesis of lignin and, in conjunction with auxin, differentiation of xylem. In particular, a potential role for borate in regulating the hydroxylase and oxidase activities of the phenolases involved in the biosynthesis of caffeic and hydroxyferulic acids is suggested. The origin of this role for boron depended on the selection of sucrose in the Chlorophyta as a mobile and storage carbohydrate since, compared with the acyclic sugar alcohols accumulated in other algal groups, sucrose forms only a very weak complex with borate. It is argued that only when borate was not sequestered by complexing with other carbohydrates did the way become clear for it to acquire an essential role. This acquisition catalysed the evolutionary dichotomy between non-lignified and lignified photosynthetic landplants, the bryophytes and tracheophytes. Boron subsequently became involved in two other requirements for success on land -the exploitation of soil for anchorage, water and minerals, and the emancipation of fertilization from external water-since this element is required for development of adventitious roots (again in conjunction with plant hormones) and, in angiospertns, for germination of pollen.

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“…B deficiency and toxicity are common. B is essential for pollen tube growth (Marschner, 1986) and B deficiency reduces the root growth rate (Bohnsack and Albert, 1977).…”

Section: Introductionmentioning

confidence: 99%

“…B deficiency and toxicity are common. B is essential for pollen tube growth (Marschner, 1986) and B deficiency reduces the root growth rate (Bohnsack and Albert, 1977).In general, B in soil can be divided into three categories (Keren and Bingham, 1985): (1) B in primary minerals, such as tourmaline (borosilicate minerals), (2) B adsorbed by soil constituents, such as clay minerals, hydroxide of Al and Fe, organic matter, and (3) B in soil solutions such as boric acid and borate ions.We previously reported that the available B content in tropical peat soils (Yonebayashi and Yamada, 2000) is markedly less than that in mineral soils. It is not clear whether this stems from the low solubility of soil B or from the low content of total B in peat soils.…”

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confidence: 99%

Evidence of sea water Boron in the lower layers of tropical woody peat

Yonebayashi

Yamada

Suzuki

et al. 2004

Tropics

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INTRODUCTIONTropical peat consists of plant residues of former forests in varying degrees of decomposition. Tropical peatland contains a greater diversity of woody plant species than that found in temperate regions. The latter developed from grass plants such as reeds, sedges and Sphagnum. In tropical peat, well-preserved woody materials are commonly found within the matrix of dark brown amorphous materials. The properties of tropical peat are based on several factors (Driessen, 1978;Bouman and Driessen, 1985), including the nature of the original plants, wood content, degree of decomposition, the supply of inorganic solutes, the environmental conditions, peat stratification, and compactions.The total area of tropical peat swamps or tropical peatlands in the world amounts to about 30 Mha, two thirds of which are in Southeast Asia (Driessen, 1978). The peatlands are mostly in Sumatra, Kalimantan, and West Papua. Over 8 Mha of Indonesia's peatlands are deeper than 2 m. Inland peat deposits with greater than 15 m depth are found in the high altitude peatlands (Rieley et al., 1992). Many of them appear to have been formed in the early and middle Holocene era (Neuzil, 1997).Large areas of coastal lowland peatlands have been exploited for agricultural development, and the difficulties of their large-scale development are widely known. The low fertility (Chew et al., 1978;Yonebayashi et al., 1994) and polyphenolic toxicity (Driessen and Suhardjo, 1976) are among the factors causing agricultural production failure. The optimum utilization of peatlands depends on its characteristics.Boron is one of the essential trace elements for vascular plants. It is important in the metabolism of saccharides and synthesis of the cell walls of plants. The range of B concentrations that are optimum for plant growth, is narrow. B deficiency and toxicity are common. B is essential for pollen tube growth (Marschner, 1986) and B deficiency reduces the root growth rate (Bohnsack and Albert, 1977).In general, B in soil can be divided into three categories (Keren and Bingham, 1985): (1) B in primary minerals, such as tourmaline (borosilicate minerals), (2) B adsorbed by soil constituents, such as clay minerals, hydroxide of Al and Fe, organic matter, and (3) B in soil solutions such as boric acid and borate ions.We previously reported that the available B content in tropical peat soils (Yonebayashi and Yamada, 2000) is markedly less than that in mineral soils. It is not clear whether this stems from the low solubility of soil B or from the low content of total B in peat soils.In the peat soil ecosystems, many nutrient elements circulate between peat and plants, and the nutrients are repeatedly utilized. The regeneration of plants becomes possible in a closed ecosystem such as peatlands (Yonebayashi et al., 1997). A new supply of nutrient elements is not provided in deep peat, because plant roots do not reach the mineral soil layer under the peat. In the peat ecosystem, most of the heavy metals are retained in the peat as chelates (Yonebayashi...

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Early Effects of Boron Deficiency on Indoleacetic Acid Oxidase Levels of Squash Root Tips

Cited by 89 publications

References 18 publications

Synthesis, Salvage, and Catabolism of Uridine Nucleotides in Boron-Deficient Squash Roots

Synthesis, Salvage, and Catabolism of Uridine Nucleotides in Boron-Deficient Squash Roots

Boron, Lignification and the Origin of Vascular Plants‐a Unified Hypothesis

Evidence of sea water Boron in the lower layers of tropical woody peat

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