Effect Of Potassium Deficiency Research Articles

Effect of Potassium Deficiency on Physiological Responses and Anatomical Structure of Basil, Ocimum basilicum L.

The aim of this study was to investigate the effect of a variable supply of potassium to culture medium on physiological and anatomical parameters (histological sections at the third internode) in basil, Ocimum basilicum. Thirty-four-day-old plants grown on basic nutrient medium were divided into four batches and grown on media with varying doses of potassium: 0.375 mM, 0.250 mM, 0.125 mM and 0 mM K+. After 64 days of culture, a final harvest was performed. The results showed that root and shoot growth in basil was decreased with decreased K+ concentration. This restriction was associated with a reduction in root elongation and leaf expansion, which was coupled with a decrease in chlorophyll and carotenoid contents. The estimation of electrolyte leakage reveals that this parameter was increased by potassium deficiency. With respect to total polyphenol and flavonoid contents, only the third leaf-stage extracts exhibited a decrease under low-K+ conditions. However, variability in response of phenolic compounds was recorded depending on the organ and the K+ concentration in the medium. Stem cross sections of potassium-deficient basil plants revealed a decrease in the diameter of these organs, which can be attributed to a restriction of the extent of different tissue territories (cortex and medulla), as well as by a reduction in cell size. These effects were associated with a decrease in the number of conducting vessels and an increase in the number of woody fibers.

Effect of potassium deficiency on growth, antioxidants, ionome and metabolism in rapeseed under drought stress

Previous studies have reported that potassium plays important roles in rapeseed drought tolerance, however, the interrelationship between potassium and metabolism under drought stress remains unclear. In this study, physiological and metabolic responses were investigated in two cultivars Youyan57 (YY57) and Chuanyou36 (CY36) exposed to 7% PEG6000 simulated drought stress with two potassium levels (0.01 and 1.0 mM K2SO4, referred to LK and NK, respectively). Compared to NK, LK caused a more dramatic reduction in biomass and led to significant lower enzymatic activities of antioxidants under drought stress for both the two cultivars. Moreover, potassium concentration in plant tissues decreased by 29.1% in LK compared to NK averagely and induced metabolic disorder. Totally 51 metabolites changed significantly under LK compared to NK, in which amino acids and amines increased dramatically. Most carbohydrates and carbohydrate conjugates decreased at LK, while organic acids increased, including α-ketoglutaric acid, succinic acid, l-malic acid and oxalacetic acid, which could participate in tricarboxylic acid cycle (TCA) and synthesis of amino acids. The results suggested that potassium deficiency under drought stress induced the accumulation of amino acids for osmotic adjustment and balance of electric charge, while resistance related biosynthesis of amino acids and enhanced TCA cycle were high demands of carbon skeletons which affected plant growth. Cultivar YY57 kept much higher potassium concentration and antioxidant capacity than CY36 at LK, and showed less disturbance of metabolism, consequently resulting in higher biomass. Therefore, potassium uptake and retention was closely associated with rapeseed drought tolerance.

The Effect of Potassium Deficiency on Growth and Physiology in Sweetpotato [Ipomoea batatas (L.) Lam.] during Early Growth

Potassium (K+) is an essential nutrient element for the growth and development of sweetpotato [Ipomoea batatas (L.) Lam.]. To investigate growth and physiological responses to K+ deficiency during early growth stage of sweetpotato, two representative cultivars with different tolerance to K+ deficiency were chosen. The seedlings of ‘Xushu 32’ (tolerance to K+ deficiency) and ‘Ningzishu 1’ (sensitive to K+ deficiency) were cultured in three different K+ concentrations (K0: 0 mmol·L−1 K+; K1: 5 mmol·L−1 K+; and K2: 20 mmol·L−1 K+, the control) of nutrient solution. Results showed that the extreme K+ deficiency (K0) significantly reduced the total dry weight, leaf number, root length, and chlorophyll content (CCI) compared with K2. However, the growth traits of ‘Xushu 32’ were less suppressed than those of ‘Ningzishu 1’. The net photosynthetic rate (Pn), stomatal conductance (gS), and transpiration rate (Tr) of ‘Ningzishu 1’ were significantly decreased in K0 and K1 (low K+), whereas ‘Xushu 32’ showed no significant change in K1 treatment. Increasing minimal fluorensence (F0) of ‘Ningzishu 1’ comes with decreased maximum quantum efficiency of photosystem II (PSII) photochemistry (Fv/Fm) and photochemical quenching (qP) at K0 treatment. However, all the chlorophyll fluorescence parameters in ‘Xushu 32’ were nonsignificantly changed by K+ deficiency (K0 and K1). These results suggest that ‘Xushu 32’ could maintain a better growth state to adapt to K+ deficiency stress, which may be mainly because of a lighter affected photosynthesis and a less damaged PSII reaction center.

Effect of potassium deficiency on antioxidant status and cadmium toxicity in rice seedlings.

BackgroundCadmium (Cd) is one of the most toxic heavy metals and inhibits physiological processes of plants. Potassium (K) is an essential macronutrient in plants. K deficiency and Cd stress represent two different abiotic stress conditions that occur in the field simultaneously. In this study, effects of K deficiency on antioxidant status and Cd toxicity in rice seedlings were investigated.ResultsK deficiency significantly decreased K concentration in shoots and roots. However, fresh weight and dry weight of rice seedlings were not affected by K deficiency. The activities of antioxidant enzymes (superoxide dismutase, ascorbate peroxidase, glutathione reductase, and catalase) in K-deficient leaves were higher than respective control leaves. However, K deficiency had no effect on the content of antioxidants (ascorbate and glutathione). Cd toxicity was judged by the decrease in biomass production, chlorosis, and induction of oxidative stress. Based on these criteria, we demonstrated that K deficiency protected rice seedling from Cd stress. Moreover, chlorophyll concentration was higher in K-deficient shoots and roots than their respective control shoots and roots.ConclusionsOur results indicated that K deficiency protects rice seedlings from Cd toxicity. This protective effect of K deficiency is mainly due to enhanced antioxidant enzyme activities but not inhibition of Cd uptake.Electronic supplementary materialThe online version of this article (doi:10.1186/1999-3110-54-2) contains supplementary material, which is available to authorized users.

Effect of potassium deficiency on the plasma membrane H+‐ATPase of the wood ray parenchyma in poplar

ABSTRACTThe effect of K+ deficiency on the plasma membrane (PM) H+‐ATPase was studied in young stems of poplar plants (Populus tremula × tremuloides) grown with low or full‐strength K+ supply. Immunological assays using different antibodies were applied to test if K+ deficiency affects the amount of immunodetectable PM H+‐ATPases in the stem tissue. The monoclonal antibody clone 46 E5 B11 revealed an increased abundance of PM H+‐ATPases under conditions of low K+ supply, and immunolabelling experiments showed that this increase was restricted to vessel‐associated cells (VACs) of the wood ray parenchyma. Replacement of the monoclonal antibody by a polyclonal antibody against PM H+‐ATPase gave a specific immunoreactivity on blots as well as tissue sections too, but the labelling intensity showed no difference between plants with low or full‐strength K+ supply. Measurements of extracellular H+ concentrations using non‐invasive, H+‐selective microelectrodes revealed a lowering of the pH at the surface of VACs and an enhancement of net efflux of H+ in plants grown with low K+ supply. The present results indicate an up‐regulation of specific isoforms of the PM H+‐ATPase in VACs under K+‐deficient conditions and suggest a key role for these PM H+‐ATPases in unloading K+ from the xylem stream.

Effect of potassium deficiency on body temperature in mice

Body temperature in mice fed with a low-potassium diet decreased in a parallel way to the diminution of plasma potassium concentration. Both parameters were restored after potassium replenishment. Hypokalemia produced by treatment with fludrocortisone, a synthetic mineralocorticoid, did not significantly decrease mouse body temperature. The hypothermia observed in the potassium deficient mice was prevented by treatment with fludrocortisone, in spite of the fact that plasma potassium levels were remarkably reduced. The transient hyperthermic response induced by stress in control animals was also present in the potassium deficient mice. Dexamethasone prevented stress-induced hyperthermia both in control and potassium-deficient animals. The results may be partially explained by the reported effects of potassium and fludrocortisone on Na/K ATPase.

The effect of potassium deficiency on chemical, biochemical and physical factors commonly associated with blackspot development in potato tubers

Blackspot bruise is a physiological disorder of potato tubers resulting from mechanical damage to tissues during handling. This study examined the effect of potassium nutrition on biochemical and physical changes normally associated with blackspot bruise in potato tubers. Four potato (Solanum tuberosum L.) genotypes (TXA 763-5 [very resistant], Ranger Russet [very susceptible], Russet Burbank [susceptible], and Lemhi Russet [very susceptible]) differing in susceptibility to blackspot bruise were grown at three potassium nutrition levels (100%, 10% and 0% of the potassium in full strength Hoagland’s solution). Tubers from the three treatments were tested for their chemical, biochemical and physical characteristics commonly related to blackspot bruise susceptibility. The potential to develop malanin pigments was measured as total oxidative potential (optical density, OD475) of clarified tuber homogenates. Tuber tissue extracts were assayed for polyphenol oxidase (PPO) activity with catechol, measured as increase in OD410 over time. Specific gravity of tubers was determined with a brine solution series. Physical property measurements were made by impacting cores of tuber tissue in a specially designed instrumented pendulum. Shock wave speed, Young’s modulus, failure stress, and failure strain were all measured dynamically during impact. Tubers produced under both the 10% and 0% potassium regimens had almost 2x the free tyrosine of control tubers. The 0% potassium tubers had significantly higher PPO activity than the control. Both of these factors likely contributed to the significantly higher total oxidative potential that was observed in tubers from both the 10% and 0% potassium treatments. Tubers from both the 0% and 10% potassium treatments had a significantly lower Young’s modulus (a measure of stiffness), significantly lower failure stress and the shock wave of impact propagated through both of them significantly slower. Although the cultivars were significantly different in their susceptibility to black pigment development, they all responded similarly to the treatment with regards to the variables measured. The TXA-763-5 clone was much more susceptible to developing black pigments in these tests than expected. The other three cultivars performed as they do in commerce.

Effect of potassium deficiency on growth and some biochemical characteristics in two lines of lentil (Lens culinaris Medic.)

The effect of low potassium regimes on two lines, ILL 6796 (salt-tolcrant) and ILL 6439 (salt-sensitive), of lentil (Lens culinaris) was studied in a pot experiment under glasshouse conditions. Plants of the two lines were treated with 78, 39, 19.5, and 9.75 mg K·L−1 in Rorison’s nutrient solution. ILL 6796 excelled ILL 6439 in biomass production under varying K regimes. Of the various organic solutes measured in the present study only total soluble sugars proved to be helpful in discriminating the lines, i.e., total sugars increased consistently in ILL 6796 with a decrease in K level of the growth medium, whereas in ILL 6439 they decreased significantly with a decrease in K levels. ILL 6796 showing high efficiency for K utilisation (high shoot growth) could be of great economic value in terms of its use in soils deficient in K.

Effect of potassium deficiency and gossypol on urinary N-acetyl-β-glucosaminidase excretion in the rat

Some men receiving gossypol in China developed elevated urinary N-acetyl-β-glucosaminidase (NAG) levels and hypokalemia. Since idiopathic hypokalemia occurs in China, hypokalemic nephropathy may have caused the elevated NAG levels. To learn if gossypol is directly nephrotoxic, we treated rats with a normal or low potassium diet with or without gossypol. The low potassium diet produced high NAG levels rather than the gossypol. This indicates the importance of differentiating hypokalemic nephropathy from drug nephrotoxicity in regions where idiopathic hypokalemia occurs.

Efeito da deficiência de potássio sobre as atividades de glutamato desidrogenase e glutamato sintase em feijoeiro (Phaseolus vulgaris L.)

Foi estudado o efeito da deficiência de potássio sobre as atividades da glutamato desidrogenase (EC. 1.4.1.2) e glutamato sintase (EC. 2.6.1.53) em folhas de feijoeiro (Phaseolus vulgaris L.). Os resultados mostraram que a atividade específica da glutamato desidrogenase aumentou nas plantas deficientes em potássio nos dois cultivares estudados. Foi detectada redução na atividade de glutamato sintase nas plantas deficientes em potássio.

Effect of Potassium Deficiency on the Endocochlear Potential

Effect of Potassium Deficiency on the Endocochlear Potential

Effect of potassium deficiency on growth and metabolism of peanut (Arachis hypogaea L.) plants

Potassium deficiency effects on growth, nitrogen and carbohydrate fractions and minerals were studied in 30 day-old peanut plants. Reduced stem length, tap root length and reduced number of leaves and primary laterals were noticed in K+ deficient plants. In addition, decreased levels of total protein and soluble nitrogen fractions were observed. However, high amounts of starch and total sugars were found in all the three component parts of the plant under K+ deficiency. K+ deficiency also decreased the levels of potassium and calcium but increased the level of total phosphorus in peanut plants. The relevance of these changes has been discussed.

The Effect of Potassium Deficiency on Stomatal and Cuticular Resistance in Tea (Camellia sinensis)

AbstractThe effect of potassium deficiency on cuticular resistance and diurnal variation in stomatal diffusive resistance was studied in tea (Camellia sinensis). The plants were grown in sand and potassium deficiency induced by withholding the supply of potassium.The results showed that during the day potassium‐deficient leaves had a higher stomatal diffusive resistance than control leaves. However when solar radiation was reduced by clouds the stomatal diffusive resistance in both control and potassium‐deficient leaves was not significantly different. Night opening of stomata was observed in both control and potassium‐deficient leaves, but noticeably lower in the latter. Potassium‐deficient leaves had a lower cuticular resistance than control leaves.

Effect of potassium deficiency on papillary plasma flow in the rat.

Chronic potassium (K+) deficiency has been shown previously to cause a reduction in solute content in the renal papilla, an effect that is potentially important as a contributing factor to the concentrating defect seen in this circumstance. The cause of the decrease in papillary solute content has not been adequately explained. Because alterations in the blood flow rate through the renal papilla may affect the solute content of the papilla, the present experiments examined the effect of chronic K+ deficiency on papillary plasma flow (PPF) in the rat. PPF was measured by the radioactive albumin accumulation technique. Sprague-Dawley rats were fed identical quantities of water and either a normal or a K+-deficient diet for 21 days. Total GRR in the control rats, 1.7 +/- 0.17 (SE) ml/min, was similar to that in K+-deficient rats, 1.4 +/- 0.14 ml/min (P greater than 0.01). Total [3H]PAH clearance was also comparable in the two groups, i.e., 4.4 +/- 0.47 in control and 4.7 +/- 0.45 ml/min in K+-deficient rats (P greater than 0.06). PPF was significantly lower in K+-deficient rats, 19.7 +/- 1.1 ml-min-1-100 g-1, than in control rats, 59.8 +/- 1.6 ml-min-1-100 g-1 (P less than 0.001). The decrease in PPF in the K+-deficient rat may reflect a reduction in perfusion to the juxtamedullary nephrons, thereby resulting in a diminution in both solute delivery and blood flow to the papilla.

Effect of Potassium Deficiency on Cellular Composition

Effect of Potassium Deficiency on Cellular Composition

Effect of potassium deficiency on mouse kidney lysosomal enzymes.

Mice of inbred strains A/J, C57BL/6J and C57BL/6J beige were kept on a K+-deficient diet for up to 40 days to determine the magnitude and mechanism of changes in tissue lysosomal enzymes. From days 10 to 40 glucuronidase activity increased 3-fold in kidney of K+-deficient mice, but there was little effect on beta-galactosidase or acid phosphatase activity. Similar increases in kidney glucuronidase activity occurred in inbred strains known to have genetically altered control of the synthesis (A/J) and secretion (C57BL/6J beige) of glucuronidase in kidney proximal-tubule cells. Deprivation of K+ did not affect glucuronidase activity in liver, spleen, lung and brain, but there was a 2-3-FOld increase in glucuronidase activity in heart in the C57BL/6J and C57BL/6J beige strains. As shown by specific antibody titration, increased glucuronidase activity in kidney of K+-deficient mice was accompanied by accumulation of enzyme molecules. Likewise in kidney of deficient mice there was an increased rate of synthesis of glucuronidase as measured by incorporation of labelled leucine into immunoprecipitable glucuronidase. In kidney of K+-deficient mice the elevated glucuronidase activity was found in both collecting-tubule and interstitial cells of the medulla. It is probable therefore that a significant fraction of the increased kidney lysosomal synthesis and enzyme activity is due to infiltrating cells.

The effect of potassium-deficiency on diamine oxidase activity in Pea

Pea plants grown in nutrient solution in which K+ ions were equimolarly replaced with Na+, NH4 + or Rb+ did not show morphological symptoms of potassium-deficiency. The activity of diamine oxidase in these plants was higher than in controls. Similarly higher diamine oxidase activity was found in plants grown in a complete nutrient solution supplemented with putrescine.

Effect of Potassium Deficiency on Cochlear Potentials and Cation Content in Endolymph

The scala vestibuli and/or scala tympani in guinea pigs were perfused with K+-free modified Ringer's solution. Cochlear microphonics (CM), summating potential (SP), action potential (AP), and endocochlear potential (EP) were recorded from the basal turn of the cochlea before, during, and after the perfusion. Perfusion of both scala vestibuli and tympani with the normal Ringer's did not result in appreciable changes in the cochlear potentials or Na and K content in the endolymph. Perfusion of the perilymphatic space with K+-free Ringer's caused significant suppression of EP and AP. The CM was also reduced in magnitude and accompanied by increase of the positive SP. These changes were reversible by washing with normal Ringer's. The measurement of K and Na content in the endolymph indicated that the K deficiency in the perilymph brought about significant increase of Na content and decrease of K content. The role of K ions in the perilymph for the generation of EP is discussed. [Work supported by a Public Health Service grant].

Effect of Potassium Deficiency upon Translocation of 14C in Detached Blades of Sugarcane

The translocation of radioactive photosynthate was studied in blades detached from plants which had been grown in nutrient solution with and without potassium. Basipetal translocation decreased in the blades of plants deprived of potassium, even when deficiency symptoms were not visible. In such slightly potassium-deficient leaves, translocation was decreased in the light but not in the dark. More severe potassium deficiency decreased translocation both in darkness and in light. Potassium deficiency decreased translocation at light intensities giving no difference in rate of photosynthesis between plus and minus potassium leaves and even at light intensities at which there was no net fixation of carbon dioxide. At all levels of deficiency, the relative decrease in translocation was greater than the relative decrease in photosynthesis. Translocation was affected at potassium deficiency levels which had no effect upon photosynthesis.Potassium deficiency decreased translocation relatively more than it decreased moisture content. There was a much better correlation between the decrease in potassium and translocation than between the decrease in moisture and translocation.An experiment with radioactive phosphorus indicated an upset in phosphorylation in the stems of potassium-deficient plants.

Effect of Potassium Deficiency Upon Translocation of 14C in Attached Blades and Entire Plants of Sugarcane

A deficiency in potassium decreased the translocation of labeled photosynthate from the leaf to the rest of the plant. Translocation was inhibited in blades which exhibited no visible symptoms of potassium deficiency and in which no decrease in photosynthesis was detected. In more severe deficiency both the rate of photosynthesis and the conversion of intermediates to end products decreased. The rate of respiration in deficient blades increased. The decrease in translocation caused by potassium deficiency is considered to be a primary effect and not secondary to the development of the well-known symptoms of potassium deficiency.