Boron and Calcium Sites Involved in Indole-3-Acetic Acid Transport in Sunflower Hypocotyl Segments

Tang, Pauline M.; Fuente, R. K. dela

doi:10.1104/pp.81.2.651

Cited by 22 publications

(12 citation statements)

References 8 publications

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“…Incubation in B solution caused a slight but significant increase in auxin transport, compared to segments incubated in water. More data on this question is shown in the accompanying manuscript (26).…”

Section: Resultsmentioning

confidence: 99%

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The Transport of Indole-3-Acetic Acid in Boron- and Calcium-Deficient Sunflower Hypocotyl Segments

Tang

Fuente²

1986

Plant Physiol.

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Transfer of sunflower (Helianthus annuus L. cv Russian Mammoth) seedlings from complete nutrient solution to solutions deficient in either boron or calcium resulted in a steady decline in the rate of auxin transport, compared to seedlings that remained in the complete solution. In seedlings transferred to solutions deficient in both B and Ca, the decline in auxin transport was greater than seedlings deficient in only one element. The transfer of B-or Ca-deficient seedlings back to the complete solution prevented further decline in auxin transport, but auxin transport did not increase to the same level as seedlings maintained in complete solution. The significant reduction in auxin transport during the early stages of B or Ca deficiency was not related to (a) reduced growth rate of the hypocotyl, (b) increased acropetal movement of auxin, or (c) lack of respiratory substrates in the hypocotyl. In addition, no difference was found in the water-extractable total and ionic Ca in B-deficient and control nondeficient hypocotyls, indicating a direct effect of B on auxin transport, rather than indirectly by affecting Ca absorption. The rate of auxin transport in hypocotyls deficient in either B or Ca, was inversely correlated with K' leakage and rate of respiration. The data presented strongly support the view that there are separate sites for B and Ca in the basipetal transport of the plant hormone indoleacetic acid.Recently it was demonstrated that Ca is essential in the basipetal transport or secretion of auxin in sunflower hypocotyl segments (5, 7). It was hypothesized that Ca probably functions in the same way that this element does in the secretion of many kinds of substances in animal cells (21 the hypocotyl 1800 relative to gravity. Also, the acropetal efflux of Ca was inhibited by cyanide and low temperature, just as the basipetal transport of auxin (4).Although these findings support our hypothesis, it can be argued that our observations regarding the Ca-IAA transport relationship still appears to be more apparent than real. To probe this hypothesis further, we sought the use of other model systems. The main question is whether the findings of a Ca requirement in auxin transport, and the auxin promotion of Ca efflux at the hypocotyl level, is an accurate representation ofthe phenomenon at the cell level. It is possible that these findings are the direct effect of the overall disturbance in the hypocotyl, such as apical necrosis, increase membrane permeability, etc., resulting from Ca deficiency, and thus only indirectly to the deficiency of Ca. To this end we used the B-deficient seedling for the following reasons.Both B and Ca are considered immobile elements in plant systems (19,20). Deficiency or withdrawal of B or Ca from the root medium leads to necrosis of young tissues in roots and shoots, leaving the older portions of the plant relatively unaffected. The avid binding ofCa to the cell wall (23), and of H3BO3 to membrane and cell wall components with cis-hydroxyl configurations (14), together wit...

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Section: Resultsmentioning

confidence: 99%

“…At this point the specific number of sites involved in auxin transport affected by deficiency of each element is not clear. In the accompanying manuscript (26) we detail how we distinguished and characterized two possible sites each for B and Ca involved in auxin transport.…”

Section: Discussionmentioning

confidence: 99%

The Transport of Indole-3-Acetic Acid in Boron- and Calcium-Deficient Sunflower Hypocotyl Segments

Tang

Fuente²

1986

Plant Physiol.

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“…It was reported that B plays a significant role in transport of carbohydrates, cell wall metabolism [22], permeability and stability of cell membranes [10], phenol metabolism, and lignin biosynthesis (11,54). It was shown that B deficiency induced plasma membrane solute leakage [20,55], inhibited meristematic tissue development [11], and affected cell wall integrity [21]. Other researchers found that at the early stage of water stress (0 -14 d), the activity of some enzymes involved in lignin biosynthesis such as phenyl alanine ammonialyase and ascorbate peroxidase increased.…”

Section: Lignin Phenol and Boronmentioning

confidence: 99%

“…Recently, it was found that foliar B fertilizer improved seed protein and seed oleic fatty acid in soybean [16], seed yield and seed quality in al-falfa [12], and increased fruit set [18]. Boron deficiency reduces stomatal opening and transpiration [19], induces plasma membrane solute leakage [20], inhibits meristematic tissue development, resulting in growth inhibition [11] and maintenance of cell wall integrity [21]. Boron also plays a vital role in transport of carbohydrates, cell wall metabolism [22], permeability and stability of cell membranes, and phenol metabolism [11].…”

Section: Introductionmentioning

confidence: 99%

Soybean Seed Phenol, Lignin, and Isoflavones and Sugars Composition Altered by Foliar Boron Application in Soybean under Water Stress

Bellaloui¹

2012

FNS

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Previous research showed that foliar boron (B) application at flowering or seed-fill growth stages altered seed protein, oil, and fatty acids. The objective of this research was to investigate the effects of foliar B fertilizer on seed phenolics (phenol, lignin, and isoflavones) and sugars concentrations. A repeated greenhouse experiment was conducted on soybean [(Glycine max(L.) Merr.)] under watered and water-stressed conditions. Soybean plants were divided into different sets, and each set was subjected to one of the following treatments: W = plants were watered with no foliar B; WB = plants were watered and received foliar B; WS = plants were water-stressed with no foliar B; WSB = plants were waterstressed and received foliar B. Foliar B was applied at rate of 0.45 kg/ha twice at flowering and twice at seed-fill stages. The results showed that total phenol and lignin concentrations were higher in seed collected from water-stressed plants compared with those collected from watered plants whether B was applied or not. The higher total phenol and lignin concentration in seed collected of water-stressed plants may be due to B-deficiency in plant tissues. Application of B resulted in higher concentrations of total seed B and isoflavones under watered and water-stressed plants. Higher cell wall B was higher in water-stressed plants than in watered plants, having an opposite trend to total B. Application of B resulted in higher seed sucrose in watered and water-stressed plants, but raffinose and stachyose were significantly higher under water-stressed plants. The research demonstrated that foliar B fertilizer altered seed phenol, lignin, isoflavones, and sugars, suggesting that B involved in phenolics and sugar metabolism. The higher cell wall B in waterstressed plants than in watered plants supports previous research that B has mainly a structural role. The higher sucrose resulting from foliar B in watered plants is desirable as sucrose contributes to seed quality. The increase of raffinose and stachyose concentrations in seed of water-stressed plants is undesirable as raffinose, and especially stachyose may be involved in water stress/drought tolerance. The current knowledge would help soybean breeders select for higher phenolic compounds and desirable sugars for higher seed qualities under drought conditions.

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“…Figure 1 shows that 1 mM Ca2+ increases net IAA uptake into pea epicotyl segments from the very start of the incubation . This implies a role for Ca 2 + either in the control of IAA attachment to membranes, IAA permeation through the membrane or IAA transport, as already proposed by Tang and Dela Fuente [27] . We think one may exclude a Ca 2+ induced pH effect on IAA uptake, since the experiments were conducted in 2 .5 mM MES buffer at pH 6.5, and at times even with 20 mM MES buffer .…”

Section: Effect On Iaa Asymmetry and Gravicurvaturementioning

confidence: 66%

On the role of calcium in indole-3-acetic acid movement and graviresponse in etiolated pea epicotyls

Migliaccio

Galston

1989

Plant Growth Regul

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To determine whether Ca2+ plays a special role in the early graviresponse of shoots, as has been reported for roots, we treated etiolated pea epicotyls with substances known to antagonize Ca2+ (La3+), to remove Ca2+ from the wall (spermidine, EGTA), to inhibit calmodulin mediated reactions (chlorpromazine), or to inhibit IAA transport (TIBA). We studied the effect of these substances on IAA and Ca2+ uptake into 7 mm long subapical 3rd internode etiolated pea epicotyl sections and pea leaf protoplasts, on pea epicotyl growth, and graviresponse and on lateral IAA redistribution during gravistimulation. Our results support the view that adequate Ca2+ in the apoplast is required for normal IAA uptake, transport and graviresponse. Experiments with protoplasts indicate that Ca2+ may be controlling a labile membrane porter, possibly located on the external surface of cell membrane, while inhibitor experiments suggest that calmodulin is also implicated in both the movement of IAA and graviresponse. Since a major transfer of Ca2+ through free space during graviresponse has not yet been demonstrated, and since inhibition of calcium channels does not affect IAA redistribution (Migliaccio and Galston, 1987, Plant Physiology 85:542), we conclude that no clear evidence links prior Ca2+ movement with IAA redistribution during graviresponse in stems.

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Boron and Calcium Sites Involved in Indole-3-Acetic Acid Transport in Sunflower Hypocotyl Segments

Cited by 22 publications

References 8 publications

The Transport of Indole-3-Acetic Acid in Boron- and Calcium-Deficient Sunflower Hypocotyl Segments

The Transport of Indole-3-Acetic Acid in Boron- and Calcium-Deficient Sunflower Hypocotyl Segments

Soybean Seed Phenol, Lignin, and Isoflavones and Sugars Composition Altered by Foliar Boron Application in Soybean under Water Stress

On the role of calcium in indole-3-acetic acid movement and graviresponse in etiolated pea epicotyls

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