Evidence That Sulfur Deficiency Enhances Molybdenum Transport in Xylem Sap of Tomato Plants

2005 ◽  
Vol 28 (8) ◽  
pp. 1347-1353 ◽  
Author(s):  
Ramadan A. Alhendawi ◽  
Ernest A. Kirkby ◽  
David J. Pilbeam
Agriculture ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 292
Author(s):  
Ilie Bodale ◽  
Gabriela Mihalache ◽  
Vladut Achiţei ◽  
Gabriel-Ciprian Teliban ◽  
Ana Cazacu ◽  
...  

Nutrient consumption by plants depends on the growth stage and environmental conditions. In general, plants take up species of elements at different speeds. We monitored and recorded the electrical charge flow through xylem sap of tomato plants (Brillante F1) using femto/picoammeter equipment (Keysight B2981A). This technique evaluates the nutrient uptake of tomato treated with the most common macronutrients (KNO3; KH2PO4; Ca(NO3)2; KCl) by monitoring the electrical conductivity for 24 h. The electrical conductivity of each treatment correlated with the plant growth and development stages. The results showed that the tomato plants had a high consumption of nutrients in the vegetative stage, while in other stages, they had a specific consumption, like phosphorus for bulb formation, potassium for increasing the number of flowers and water for the ripening of fruits. The quantitative evaluation of the ions absorbed by the plant was based on the magnitude and shape of the electrical conductivity curves. Our technique is an efficient method to determine nutrient consumption and is useful in predicting the deficiency of a certain element in tomato plants.


2021 ◽  
Author(s):  
April M MacIntyre ◽  
Valerian Meline ◽  
Zachary Gorman ◽  
Steven P Augustine ◽  
Carolyn J Dye ◽  
...  

Ralstonia solanacearum causes plant bacterial wilt disease, leading to severe crop losses. Xylem sap from R. solanacearum-infected tomato is enriched in host produced trehalose. Water stressed plants accumulate the disaccharide trehalose, which increases drought tolerance via abscisic acid (ABA) signaling networks. Because infected plants have reduced water flow, we hypothesized that bacterial wilt physiologically mimics drought stress, which trehalose could mitigate. Transcriptomic responses of susceptible vs. resistant tomato plants to R. solanacearum infection revealed differential expression of drought-associated genes, including those involved in ABA and trehalose metabolism. ABA was enriched in xylem sap from R. solanacearum-infected plants. Treating roots with ABA lowered stomatal conductance and reduced R. solanacearum stem colonization. Treating roots with trehalose increased ABA in xylem sap and reduced plant water use by reducing stomatal conductance and temporarily improving water use efficiency. Further, trehalose-treated plants were more resistant to bacterial wilt disease. Trehalose treatment also upregulated expression of salicylic acid (SA)-dependent defense genes, increased xylem sap levels of SA and other antimicrobial compounds, and increased wilt resistance of SA-insensitive NahG tomato plants. Additionally, trehalose treatment increased xylem concentrations of jasmonic acid and related oxylipins. Together, these data show that exogenous trehalose reduced both water stress and bacterial wilt disease and triggered systemic resistance. This suite of responses revealed unexpected linkages between plant responses to biotic and abiotic stress and suggests that that R. solanacearum-infected tomato plants produce more trehalose to improve water use efficiency and increase wilt disease resistance. In turn, R. solanacearum degrades trehalose as a counter-defense.


Agronomy ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 182 ◽  
Author(s):  
Francisco Albornoz ◽  
Alonso G. Pérez-Donoso ◽  
Jorge Leigh Urbina ◽  
Matías Monasterio ◽  
Miguel Gómez ◽  
...  

Vigorous interspecific rootstocks increase nitrogen (N) uptake in tomato plants but limited information is available on xylem transport rate. Non-grafted and self-grafted tomato plants cv. Attiya and plants grafted onto an interspecific hybrid, Kaiser, were grown under growth chamber conditions and subjected to two light levels, 400 or 800 µmol PAR m−2 s−1. Plant water uptake, xylem sap NO3− content, and stem hydraulic conductance (ks) were measured after two weeks of growth. Xylem vessel number and diameter were evaluated in cross-sectional stem cuts and the theoretical xylem hydraulic conductance (kh) was calculated. Only the light level modified the xylem NO3− content. Grafting reduced ks by 84% in comparison to non-grafted plants. The water uptake rate and xylem sap NO3− content were 4.02 ± 0.66 g H2O kg−1 DW h−1 and 12.78 ± 1.16 mM, respectively, across all grafting treatments. The rootstock has a higher kh because the vessel diameter is 79.3 ± 14.4 µm while in non-grafted plants it is 62.0 ± 10.1 µm. Nitrate concentration and transport rate changes accordingly to the plant’s growth rate. The vigorous rootstock relies on larger vessels to supply the required amounts of N.


1984 ◽  
Vol 7 (11) ◽  
pp. 1529-1543 ◽  
Author(s):  
A. Cerdá ◽  
V. Martínez ◽  
M. Caro ◽  
F.G. Fernández

2020 ◽  
Vol 21 (8) ◽  
pp. 2971 ◽  
Author(s):  
Alaa Allahham ◽  
Satomi Kanno ◽  
Liu Zhang ◽  
Akiko Maruyama-Nakashita

Recent studies have shown various metabolic and transcriptomic interactions between sulfur (S) and phosphorus (P) in plants. However, most studies have focused on the effects of phosphate (Pi) availability and P signaling pathways on S homeostasis, whereas the effects of S availability on P homeostasis remain largely unknown. In this study, we investigated the interactions between S and P from the perspective of S availability. We investigated the effects of S availability on Pi uptake, transport, and accumulation in Arabidopsis thaliana grown under sulfur sufficiency (+S) and deficiency (−S). Total P in shoots was significantly increased under −S owing to higher Pi accumulation. This accumulation was facilitated by increased Pi uptake under −S. In addition, −S increased root-to-shoot Pi transport, which was indicated by the increased Pi levels in xylem sap under −S. The −S-increased Pi level in the xylem sap was diminished in the disruption lines of PHT1;9 and PHO1, which are involved in root-to-shoot Pi transport. Our findings indicate a new aspect of the interaction between S and P by listing the increased Pi accumulation as part of −S responses and by highlighting the effects of −S on Pi uptake, transport, and homeostasis.


Plants ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 573
Author(s):  
Martina Paponov ◽  
Aleksandr Arakelyan ◽  
Petre I. Dobrev ◽  
Michel J. Verheul ◽  
Ivan A. Paponov

Continuous light (CL) or a predominant nitrogen supply as ammonium (NH4+) can induce leaf chlorosis and inhibit plant growth. The similarity in injuries caused by CL and NH4+ suggests involvement of overlapping mechanisms in plant responses to these conditions; however, these mechanisms are poorly understood. We addressed this topic by conducting full factorial experiments with tomato plants to investigate the effects of NO3− or NH4+ supply under diurnal light (DL) or CL. We used plants at ages of 26 and 15 days after sowing to initiate the treatments, and we modulated the intensity of the stress induced by CL and an exclusive NH4+ supply from mild to strong. Under DL, we also studied the effect of nitrogen (N) deficiency and mixed application of NO3− and NH4+. Under strong stress, CL and exclusive NH4+ supply synergistically inhibited plant growth and reduced chlorophyll content. Under mild stress, when no synergetic effect between CL and NH4+ was apparent on plant growth and chlorophyll content, we found a synergetic effect of CL and NH4+ on the accumulation of several plant stress hormones, with an especially strong effect for jasmonic acid (JA) and 1-aminocyclopropane-1-carboxylic acid (ACC), the immediate precursor of ethylene, in xylem sap. This modulation of the hormonal composition suggests a potential role for these plant hormones in plant growth responses to the combined application of CL and NH4+. No synergetic effect was observed between CL and NH4+ for the accumulation of soluble carbohydrates or of mineral ions, indicating that these plant traits are less sensitive than the modulation of hormonal composition in xylem sap to the combined CL and NH4+ application. Under diurnal light, NH4+ did not affect the hormonal composition of xylem sap; however, N deficiency strongly increased the concentrations of phaseic acid (PA), JA, and salicylic acid (SA), indicating that decreased N concentration rather than the presence of NO3− or NH4+ in the nutrient solution drives the hormone composition of the xylem sap. In conclusion, N deficiency or a combined application of CL and NH4+ induced the accumulation of JA in xylem sap. This accumulation, in combination with other plant hormones, defines the specific plant response to stress conditions.


2004 ◽  
Vol 186 (23) ◽  
pp. 7896-7904 ◽  
Author(s):  
Garima Bhatt ◽  
Timothy P. Denny

ABSTRACT PhcA is a transcriptional regulator that activates expression of multiple virulence genes in the plant pathogen Ralstonia solanacearum. Relative to their wild-type parents, phcA mutants overproduced iron-scavenging activity detected with chrome azurol S siderophore detection medium. Transposon mutagenesis of strain AW1-PC (phcA1) generated strain GB6, which was siderophore negative but retained weak iron-scavenging activity. The ssd gene inactivated in GB6 encodes a protein similar to group IV amino acid decarboxylases, and its transcription was repressed by iron(III) and PhcA. ssd is the terminal gene in a putative operon that also appears to encode three siderophore synthetase subunits, a integral membrane exporter, and three genes with no obvious role in siderophore production. A homologous operon was found in the genomes of Ralstonia metallidurans and Staphylococcus aureus, both of which produce the polycarboxylate siderophore staphyloferrin B. Comparison of the siderophores present in culture supernatants of R. solanacearum, R. metallidurans, and Bacillus megaterium using chemical tests, a siderophore utilization bioassay, thin-layer chromatography, and mass spectroscopy indicated that R. solanacearum produces staphyloferrin B rather than schizokinen as was reported previously. Inactivation of ssd in a wild-type AW1 background resulted in a mutant almost incapable of scavenging iron but normally virulent on tomato plants. AW1 did not produce siderophore activity when cultured in tomato xylem sap, suggesting that the main location in tomato for R. solanacearum during pathogenesis is iron replete.


2000 ◽  
Vol 23 (8) ◽  
pp. 1051-1062 ◽  
Author(s):  
Philippe Morard ◽  
Ludovic Lacoste ◽  
Jérôme Silvestre

2020 ◽  
Vol 33 (3) ◽  
pp. 462-473 ◽  
Author(s):  
April M. MacIntyre ◽  
John X. Barth ◽  
Molly C. Pellitteri Hahn ◽  
Cameron O. Scarlett ◽  
Stéphane Genin ◽  
...  

The xylem-dwelling plant pathogen Ralstonia solanacearum changes the chemical composition of host xylem sap during bacterial wilt disease. The disaccharide trehalose, implicated in stress tolerance across all kingdoms of life, is enriched in sap from R. solanacearum–infected tomato plants. Trehalose in xylem sap could be synthesized by the bacterium, the plant, or both. To investigate the source and role of trehalose metabolism during wilt disease, we evaluated the effects of deleting the three trehalose synthesis pathways in the pathogen: TreYZ, TreS, and OtsAB, as well as its sole trehalase, TreA. A quadruple treY/treS/otsA/treA mutant produced 30-fold less intracellular trehalose than the wild-type strain missing the trehalase enzyme. This trehalose-nonproducing mutant had reduced tolerance to osmotic stress, which the bacterium likely experiences in plant xylem vessels. Following naturalistic soil-soak inoculation of tomato plants, this triple mutant did not cause disease as well as wild-type R. solanacearum. Further, the wild-type strain out-competed the trehalose-nonproducing mutant by over 600-fold when tomato plants were coinoculated with both strains, showing that trehalose biosynthesis helps R. solanacearum overcome environmental stresses during infection. An otsA (trehalose-6-phosphate synthase) single mutant behaved similarly to ΔtreY/treS/otsA in all experimental settings, suggesting that the OtsAB pathway is the dominant trehalose synthesis pathway in R. solanacearum.


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