The Experts below are selected from a list of 7980 Experts worldwide ranked by ideXlab platform
Patrick Armengaud - One of the best experts on this subject based on the ideXlab platform.
-
Potassium Deficiency induces the biosynthesis of oxylipins and glucosinolates in arabidopsis thaliana
BMC Plant Biology, 2010Co-Authors: Stephanie Troufflard, William Mullen, Tony R Larson, Ian A Graham, Alan Crozier, Anna Amtmann, Patrick ArmengaudAbstract:Background Mineral fertilization and pest control are essential and costly requirements for modern crop production. The two measures go hand in hand because plant mineral status affects plant susceptibility to pests and vice versa. Nutrient Deficiency triggers specific responses in plants that optimize nutrient acquisition and reprogram metabolism. K-deficient plants illustrate these strategies by inducing high-affinity K-uptake and adjusting primary metabolism. Whether and how K deficient plants also alter their secondary metabolism for nutrient management and defense is not known.
-
Potassium Deficiency induces the biosynthesis of oxylipins and glucosinolates in arabidopsis thaliana
BMC Plant Biology, 2010Co-Authors: Stephanie Troufflard, William Mullen, Tony R Larson, Ian A Graham, Alan Crozier, Anna Amtmann, Patrick ArmengaudAbstract:Mineral fertilization and pest control are essential and costly requirements for modern crop production. The two measures go hand in hand because plant mineral status affects plant susceptibility to pests and vice versa. Nutrient Deficiency triggers specific responses in plants that optimize nutrient acquisition and reprogram metabolism. K-deficient plants illustrate these strategies by inducing high-affinity K-uptake and adjusting primary metabolism. Whether and how K deficient plants also alter their secondary metabolism for nutrient management and defense is not known. Here we show that K-deficient plants contain higher levels of the phytohormone jasmonic acid (JA), hydroxy-12-oxo-octadecadienoic acids (HODs) and 12-oxo-phytodienoic acid (OPDA) than K-sufficient plants. Up-regulation of the 13-LOX pathway in response to low K was evident in increased transcript levels of several biosynthetic enzymes. Indole and aliphatic glucosinolates accumulated in response to K-Deficiency in a manner that was respectively dependent or independent on signaling through Coronatine-Insensitive 1 (COI1). Transcript and glucosinolate profiles of K-deficient plants resembled those of herbivore attacked plants. Based on our results we propose that under K-Deficiency plants produce oxylipins and glucosinolates to enhance their defense potential against herbivorous insects and create reversible storage for excess S and N.
G Levy - One of the best experts on this subject based on the ideXlab platform.
-
contribution of different solutes to the cell osmotic pressure in tap and lateral roots of maritime pine seedlings effects of a Potassium Deficiency and of an all macronutrient Deficiency
Annals of Forest Science, 1998Co-Authors: Mariebeatrice Bogeattriboulot, G LevyAbstract:Seedlings of maritime pine (Pinus pinaster Ait.) were grown in hydroponics and submitted either to a Potassium Deficiency or to an all-macronutrient Deficiency. In response to both nutrient stresses, tap root elongation was maintained while lateral root elongation was severely reduced. In both treatments, K content was decreased to 0.85 % of dry weight in roots and in shoots. Other minerals were little affected by the single Deficiency except nitrogen, whose content increased significantly in roots. Measurements of the concentrations of inorganic ions, sol- uble sugars and amino acids on a tissue water basis revealed that, in unstressed plants, Potassium, phosphate, choride, glucose, fructose and glutamine accounted for about two thirds of cell osmotic pressure with relative contributions depending on location in the root system. In seedlings subjected to Deficiency, K was more or less efficiently replaced by soluble sugars, glutamine and/or sodium according to location in the root system. Osmotic pressure was better maintained in younger tissues but also in tap root tip as compared to lateral root tip.
-
effects of Potassium Deficiency on cell water relations and elongation of tap and lateral roots of maritime pine seedlings
New Phytologist, 1997Co-Authors: Mariebeatrice Triboulot, Jeremy Pritchard, G LevyAbstract:SUMMARY The effects of Potassium Deficiency (KD) and all-macronutrient Deficiency (MD) on elongation of tap and lateral roots were studied on maritime pine seedlings (Pinus pinaster Ait.) in hydroponic culture. Tap root elongation was unaffected by either of the two deficiencies. By marked contrast, lateral root elongation was strongly reduced. The analyses of cell turgor pressure and relative elemental growth rate (REGR) profile in the growing zone allowed us to determine the effects of the nutrient stresses on cell-wall properties. For both Deficiency treatments, elongation rate, REGR profile (measured only for control and KD) and turgor pressure in the fastest growing cells were unaffected in the tap root, suggesting that KD and MD did not modify cell-wall properties in the growing zone. In lateral roots, KD shortened the growing zone and significantly reduced REGR. However, turgor pressure remained unaffected in this region. The absence of turgor pressure change suggests that KD reduced elongation of lateral roots by tightening cell walls. In mature cells of the two types of roots, turgor and osmotic pressures tended to be reduced by the nutrient deficiencies, indicating that these parameters were better maintained in the growing cells. Cell turgor and osmotic pressures of control plants were 0.1 MPa lower at 30 mm (mature cells) than at 2–4 mm (expanding cells) from the meristem. Moreover, these parameters were 0.1 MPa lower in expanding cells of lateral roots than in those of tap the root. Turgor and osmotic pressures were not homogeneous throughout the root system and were affected differently by the nutrient deficiencies depending on the location in the root system.
Mario G. Bianchetti - One of the best experts on this subject based on the ideXlab platform.
-
Prevention of cardiac arrhythmias in pediatric patients with normotensive-hypokalemic tubulopathy
Pediatric Nephrology, 2003Co-Authors: Cinzia Cortesi, Pietro E. G. Foglia, Alberto Bettinelli, Mario G. BianchettiAbstract:Potassium Deficiency predisposes to cardiac arrhythmias culminating in syncope or sudden death. Because of the uncertainty related to the possible occurrence of such cardiac arrhythmias in the context of normotensive-hypokalemic tubulopathies, 19 European pediatric nephrologists with a large experience of normotensive-hypokalemic tubulopathies were asked to answer a questionnaire. The responses suggest that inherited normotensive-hypokalemic tubulopathies per se do not strongly predispose to dangerous cardiac arrhythmias. However, cardiac arrhythmias may be acutely precipitated by drugs that prolong the QT interval, by diarrhea, or vomiting, and perhaps even by physical activity. Finally, the likelihood of dangerous arrhythmias in normotensive-hypokalemic tubulopathy is currently unknown.
Girdhar K Pandey - One of the best experts on this subject based on the ideXlab platform.
-
gene expression analysis of rice seedling under Potassium deprivation reveals major changes in metabolism and signaling components
PLOS ONE, 2013Co-Authors: Alka Shankar, Amarjeet Singh, Poonam Kanwar, Ashish Kumar Srivastava, Amita Pandey, Penna Suprasanna, Sanjay Kapoor, Girdhar K PandeyAbstract:Plant nutrition is one of the important areas for improving the yield and quality in crops as well as non-crop plants. Potassium is an essential plant nutrient and is required in abundance for their proper growth and development. Potassium Deficiency directly affects the plant growth and hence crop yield and production. Recently, Potassium-dependent transcriptomic analysis has been performed in the model plant Arabidopsis, however in cereals and crop plants; such a transcriptome analysis has not been undertaken till date. In rice, the molecular mechanism for the regulation of Potassium starvation responses has not been investigated in detail. Here, we present a combined physiological and whole genome transcriptomic study of rice seedlings exposed to a brief period of Potassium Deficiency then replenished with Potassium. Our results reveal that the expressions of a diverse set of genes annotated with many distinct functions were altered under Potassium deprivation. Our findings highlight altered expression patterns of Potassium-responsive genes majorly involved in metabolic processes, stress responses, signaling pathways, transcriptional regulation, and transport of multiple molecules including K(+). Interestingly, several genes responsive to low-Potassium conditions show a reversal in expression upon resupply of Potassium. The results of this study indicate that Potassium deprivation leads to activation of multiple genes and gene networks, which may be acting in concert to sense the external Potassium and mediate uptake, distribution and ultimately adaptation to low Potassium conditions. The interplay of both upregulated and downregulated genes globally in response to Potassium deprivation determines how plants cope with the stress of nutrient Deficiency at different physiological as well as developmental stages of plants.
Zhiguo Zhou - One of the best experts on this subject based on the ideXlab platform.
-
effects of Potassium Deficiency on the enzymatic changes in developing cotton fibers
Acta Physiologiae Plantarum, 2018Co-Authors: Jiashuo Yang, Shanshan Wang, Binglin Chen, Zhiguo ZhouAbstract:Although effects of Potassium (K) on cotton growth have been explored extensively, the effects of K Deficiency on the physiological changes closely related to cotton fiber development are lacking. Thus, a 2-year field experiment was conducted with two cotton cultivars (Simian 3 and Siza 3) under 0 kg K2O ha−1 (K Deficiency) and 300 kg K2O ha−1 (K sufficiency). The results showed that tonoplast adenosine triphosphatase (V-ATPase), pyrophosphatase (PPase), plasma membrane H+-ATPase (PM H+-ATPase), phosphoenolpyruvate carboxylase (PEPC), sucrose synthesis (SuSy) and vacuolar invertase (V-INV) were highly sensitive to K Deficiency. The decreases in those enzymes resulted in low malate and soluble sugar contents, which together with low K concentration declined the driving force for fiber elongation, leading to significantly lower fiber length in the 0 kg K2O ha−1 treatment. The activity of sucrose phosphate synthase (SPS) was obviously increased by K Deficiency before 20 days post anthesis (DPA), which could partly explain the acceleration of fiber cellulose synthesis and the increase in fiber strength in the 0 kg K2O ha−1 treatment in the early stage. However, SPS activity was decreased by K Deficiency after 20 DPA and SuSy activity was reduced by K Deficiency at any sampling date, resulting in low fiber strength in the end. Compared with Simian 3, the enzymes V-ATPase, PPase, PM H+-ATPase, PEPC and SuSy during fiber elongation stage were more sensitive to K Deficiency in Siza 3, and the enzymes SuSy and SPS during fiber-thickening stage were more sensitive to K Deficiency in Siza 3, which were the important reasons causing greater decreases in final fiber length and final fiber strength for Siza 3 than Simian 3 under K Deficiency.
-
Potassium Deficiency affects the carbon nitrogen balance in cotton leaves
Plant Physiology and Biochemistry, 2017Co-Authors: Taylor D Coomer, D M Oosterhuis, Dimitra A Loka, Zhiguo ZhouAbstract:Potassium (K) plays important roles in the metabolism of carbon (C) and nitrogen (N), but studies of K Deficiency affecting C-N balance are lacking. This study explored the influence of K Deficiency on C-N interaction in cotton leaves by conducting a field experiment with cotton cultivar DP0912 under two K rates (K0: 0 kg K2O ha-1 and K67: 67 kg K2O ha-1) and a controlled environment experiment with K-deficient solution (K1: 0 mM K+) and K-sufficient solution (K2: 6 mM K+). The results showed that leaf K content, leaf number, leaf area, boll number, reproductive dry weight and total dry weight were significant lower under K Deficiency (K0 or K1). Lower total chlorophyll content and Chl a/b ratio, and decreased Pn along with lower Gs and higher Ci were measured under K Deficiency, suggesting that the decrease in Pn was resulted from non-stomatal limitation. Leaf glucose, fructose, sucrose and starch contents were higher under K Deficiency, because lower sucrose export was detected in phloem. Although leaf nitrate and ammonium contents significantly decreased, free amino acid content was increased by 40-63% under K Deficiency, since lower amino acid export was also measured in phloem. K Deficiency also induced lower soluble protein content in leaves. Leaf ATP level was significantly increased under K Deficiency, indicating ATP utilization was lower, so that less energy was supplied to C and N metabolism. The ratio of soluble sugar to free amino acid and the C/N ratio markedly increased under K Deficiency, and one reason was that the phloem export reduced more prominent for sucrose (54.6-78.0%) than amino acid (36.7-85.4%) under K Deficiency. In addition, lower phosphoenolpyruvate carboxylase activity limited malate and citrate biosynthesis under K Deficiency, causing a decrease of C flux into the amino acids, which was not beneficial for maintaining C-N balance. Sucrose phosphate synthase and nitrate reductase activities were lower under K Deficiency, which would limit sucrose biosynthesis and nitrate assimilation. This was another factor altering soluble sugar to free amino acid ratio and C/N ratio in the K-deficient leaves.
-
soil Potassium Deficiency reduces cotton fiber strength by accelerating and shortening fiber development
Scientific Reports, 2016Co-Authors: Jiashuo Yang, Binglin Chen, Wenqing Zhao, Yali Meng, Youhua Wang, Zhiguo ZhouAbstract:Low Potassium (K)-induced premature senescence in cotton has been observed worldwide, but how it affects cotton fiber properties remain unclear. We hypothesized that K Deficiency affects cotton fiber properties by causing disordered fiber development, which may in turn be caused by the induction of a carbohydrate acquisition difficulty. To investigate this issue, we employed a low-K-sensitive cotton cultivar Siza 3 and a low-K-tolerant cultivar Simian 3 and planted them in three regions of different K supply. Data concerning lint yield, Pn and main fiber properties were collected from three years of testing. Soil K Deficiency significantly accelerated fiber cellulose accumulation and dehydration processes, which, together with previous findings, suggests that the low-K induced carbohydrate acquisition difficulty could cause disordered fiber development by stimulating the expression of functional proteins such as CDKA (cyclin-dependent kinase). As a result, fiber strength and lint weight were reduced by up to 7.8% and 2.1%, respectively. Additional quantitative analysis revealed that the degree of accelerated fiber development negatively correlated with fiber strength. According to the results of this study, it is feasible to address the effects of soil K Deficiency on fiber properties using existing cultivation strategies to prevent premature senescence of cotton plants.