Effect of Sodium Nutrition and Light Upon the Concentrations of Alanine in Leaves of C4 Plants

Nable, Ross O.; Brownell, P. F.

doi:10.1071/pp9840319

Cited by 7 publications

(7 citation statements)

References 9 publications

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“…Analysis of stomata1 conductance (Boag 1981) and carbonic anhydrase (Brownell e t al. 1991) support the hypothesis of Nable and Brownell (1984) that the regeneration of the primary C 0 2 acceptor, PEP, in the mesophyll chloroplasts limits photosynthesis in sodiumdeficient plants.…”

Section: Introductionsupporting

confidence: 63%

The Role of Sodium in the Conversion of Pyruvate to Phosphoenolpyruvate in Mesophyll Chloroplasts of C4 Plants

Brownell¹,

Bielig²

1996

Functional Plant Biol.

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PEP formation from pyruvate was determined in mesophyll chloroplasts mechanically isolated from sodium-deficient and sodium-replete plants of the NADP malic enzyme-type C4 species, Kochia trichophylla. An extremely sensitive method for estimating PEP was developed which permitted determination of picomole quantities of PEP in small samples taken sequentially from the mesophyll chloroplast suspension concurrently with observations on oxygen evolution. It was shown that PEP formation requires light and depends upon the intactness of the chloroplasts. The rate of formation of PEP from pyruvate increased in the presence of the Hill reagent, oxaloacetate, thus indicating its dependence on non-cyclic photophosphorylation for the supply of ATP required in the conversion of pyruvate to PEP. The optimum inorganic phosphate concentration for PEP formation was approximately 16 mM. The rates of oxygen evolution and PEP formation were equivalent at concentrations of pyruvate up to 20 mM, suggesting tight coupling between electron transport and phosphorylation. In both Kochia trichophylla and the NAD malic enzyme-type, Panicum miliaceum, the rates of PEP formation were greater in the mesophyll chloroplasts from sodium-replete than from sodium-deficient plants.Chloroplasts resuspended in 'sodium-free'media containing less than 30 IJ.M (0.7 ppm) sodium showed reduced rates of PEP formation compared with chloroplasts resuspended in media to which 1.0 mM (23 ppm) sodium had been added. Both media contained 10 mM 'sodium-free' KCI. These results indicate that sodium ions may be required to maintain the functional integrity of the mesophyll chloroplasts and that irreversible damage is sustained when sodium is absent during their isolation.

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Section: Introductionsupporting

confidence: 63%

The Role of Sodium in the Conversion of Pyruvate to Phosphoenolpyruvate in Mesophyll Chloroplasts of C4 Plants

Brownell¹,

Bielig²

1996

Functional Plant Biol.

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“…The three containers with plants were placed in an air-tight box made of Plexiglas (36 L) and the box was set in the environment chamber. The air was labeled with 8 IuCi '4CO2, which was prepared from 20 mg Ba'4CO3 and 10 mL 60% HC104. The initial CO2 concentration was about 400 ppm.…”

Section: Photosynthesismentioning

confidence: 99%

“…Grof et al (5) reported that organization of mesophyll chloroplasts ofKochia childsii and A. tricolor plants was a sodiumdependent process. In previous papers (1 [1][2][3][4][5][6][7][8][9][10][11][12][13], we have reported that sodium affects growth ofA. tricolor plants through its stimulation of nitrate uptake and reduction.…”

mentioning

confidence: 99%

Sodium Stimulates Growth of Panicum coloratum through Enhanced Photosynthesis

Matoh

Murata²

1990

Plant Physiol.

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A sodium-requiring C4 plant, Panicum coloratum Walt. cv Kabulabula, was grown with and without sodium. Rate of nitrogen uptake and photosynthesis were measured during the recovery from sodium deficiency. The beneficial effect of sodium on growth was apparent irrespective of nitrogen source, ammonium-or nitrate-nitrogen. The For plants raised under ammonium-N, 1 mM KNO3 was replaced by 1 mm KCI and 0.5 mm (NH4)2SO4 on d 10, and when nitrate-N, 0.5 mm (NH4)2SO4 was replaced by 1 mM KNO3, respectively, then grown until d 24 and the sodium treatment was started.Throughout this study, an environment chamber (NS 280 FHW, Takayama Seisakusho, Kyoto 610, Japan) was used under the following conditions: photoperiod 12 h and PPFD 350 tmol m-2 s-', and temperature 300 C and RH 80% for a whole day. 15N Tracer StudyWhen the sodium-deficient P. coloratum plants were supplied with sodium on d 24, nitrogen was simultaneously labeled with '5N-NO3 (99.8 atom % excess, Shoko Co. Ltd., Tokyo, Japan) or '5N-NH4 (99.8 atom % excess), and the plants were harvested at 24 and 48 h after the labeling. The culture solution was renewed each 24 h. At harvest, the roots were dipped into 10 mm CaC12 for 2 min, then washed with distilled water. The plants were dissected into root and shoot and the fresh weight was determined. The plant parts were then dried in an oven (70°C) and digested by the method of Novozamsky (9). Ammonium in the digestate was recovered by steam distillation, caught in 2 mL of 0.2 N H2SO4, and determined by the Indophenol method (16). The atom % '5N were determined by mass spectrometry. AnalysesRelative growth rate was calculated from the increase in the fresh weights and nitrate reductase was extracted and assayed as described previously (11), except that 0.01 mM DTT was replaced by 1 mm cysteine. Chl concentrations were determined by the method of Arnon (1). Sodium content was determined in the hot-water extracts ( 11) by atomic absorption spectrometry. The concentration was expressed on the basis of tissue water content.www.plantphysiol.org on May 10, 2018 -Published by Downloaded from

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“…Leaves of sodium-deficient C, plants have been shown to have increased concentrations of alanine (Nable and Brownell 1984;Grof et al 1986a) and pyruvate (Johnston et al 1988) and decreased concentration of PEP* (Johnston et al 1988). This suggests a possible block in the regeneration of PEP from pyruvate in the mesophyll chloroplasts in sodium-deficient plants.…”

Section: Introductionmentioning

confidence: 99%

Chlorophyll a/b Ratios and Photosystem Activity of Mesophyll and Bundle Sheath Fractions From Sodium-Deficient C4 Plants

Johnston¹,

Grof²,

Brownell³

1989

Functional Plant Biol.

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Significantly lower chlorophyll a b ratios were observed in mesophyll thylakoids extracted from sodiumdeficient than normal C , plants of Amaranthus tricolor, Chloris gayana and Kochia childsii. The chlorophyll a l b ratio of bundle sheath thylakoids was not generally as significantly affected by sodium nutrition as the mesophyll thylakoids.The lower chlorophyll a l b ratio in mesophyll thylakoids of sodium-deficient plants was associated with a lower photosystem I1 activity. The effect of sodium nutrition on photosystem 1 activity in the mesophyll thylakoids was dependent upon the species. Although no effect of sodium nutrition on photosystem I was observed in mesophyll thylakoids of K. childsii, photosystem I activity was greater in sodium-deficient than normal plants in A. tricolor.The photosystem I1 and I activities of the bundle sheath thylakoids were not affected by sodium nutrition in either K. childsii or A . tricolor.

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Effect of Sodium Nutrition and Light Upon the Concentrations of Alanine in Leaves of C4 Plants

Cited by 7 publications

References 9 publications

The Role of Sodium in the Conversion of Pyruvate to Phosphoenolpyruvate in Mesophyll Chloroplasts of C4 Plants

The Role of Sodium in the Conversion of Pyruvate to Phosphoenolpyruvate in Mesophyll Chloroplasts of C4 Plants

Sodium Stimulates Growth of Panicum coloratum through Enhanced Photosynthesis

Chlorophyll a/b Ratios and Photosystem Activity of Mesophyll and Bundle Sheath Fractions From Sodium-Deficient C4 Plants

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