scholarly journals Differential Aquaporin Response to Distinct Effects of Two Zn Concentrations after Foliar Application in Pak Choi (Brassica rapa L.) Plants

Agronomy ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 450 ◽  
Author(s):  
Hamideh Fatemi ◽  
Chokri Zaghdoud ◽  
Pedro A. Nortes ◽  
Micaela Carvajal ◽  
Maria del Carmen Martínez-Ballesta
Keyword(s):  
Brassica Rapa ◽  
Foliar Application ◽  
Leaf Gas Exchange ◽  
Essential Element ◽  
Hydraulic Conductance ◽  
Transcriptional Level ◽  
Root Hydraulic Conductance ◽  
Short Term ◽  
Pak Choi ◽  
Zn Concentration

Zinc (Zn) is considered an essential element with beneficial effects on plant cells; however, as a heavy metal, it may induce adverse effects on plants if its concentration exceeds a threshold. In this work, the effects of short-term and prolonged application of low (25 µM) and high (500 µM) Zn concentrations on pak choi (Brassica rapa L.) plants were evaluated. For this, two experiments were conducted. In the first, the effects of short-term (15 h) and partial foliar application were evaluated, and in the second a long-term (15 day) foliar application was applied. The results indicate that at short-term, Zn may induce a rapid hydraulic signal from the sprayed leaves to the roots, leading to changes in root hydraulic conductance but without effects on the whole-leaf gas exchange parameters. Root accumulation of Zn may prevent leaf damage. The role of different root and leaf aquaporin isoforms in the mediation of this signal is discussed, since significant variations in PIP1 and PIP2 gene expression were observed. In the second experiment, low Zn concentration had a beneficial effect on plant growth and specific aquaporin isoforms were differentially regulated at the transcriptional level in the roots. By contrast, the high Zn concentration had a detrimental effect on growth, with reductions in the root hydraulic conductance, leaf photosynthesis rate and Ca2+ uptake in the roots. The abundance of the PIP1 isoforms was significantly increased during this response. Therefore, a 25 µM Zn dose resulted in a positive effect in pak choi growth through an increased root hydraulic conductance.

scholarly journals Ethylene enhances root water transport and aquaporin expression in trembling aspen (Populus tremuloides) exposed to root hypoxia

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Xiangfeng Tan ◽  
Mengmeng Liu ◽  
Ning Du ◽  
Janusz J. Zwiazek
Keyword(s):  
Gas Exchange ◽  
Water Transport ◽  
Populus Tremuloides ◽  
Leaf Gas Exchange ◽  
Hydraulic Conductance ◽  
Root Hydraulic Conductance ◽  
Trembling Aspen ◽  
Expression Levels ◽  
Root Hypoxia ◽  
Exogenous Ethylene

Abstract Background Root hypoxia has detrimental effects on physiological processes and growth in most plants. The effects of hypoxia can be partly alleviated by ethylene. However, the tolerance mechanisms contributing to the ethylene-mediated hypoxia tolerance in plants remain poorly understood. Results In this study, we examined the effects of root hypoxia and exogenous ethylene treatments on leaf gas exchange, root hydraulic conductance, and the expression levels of several aquaporins of the plasma membrane intrinsic protein group (PIP) in trembling aspen (Populus tremuloides) seedlings. Ethylene enhanced net photosynthetic rates, transpiration rates, and root hydraulic conductance in hypoxic plants. Of the two subgroups of PIPs (PIP1 and PIP2), the protein abundance of PIP2s and the transcript abundance of PIP2;4 and PIP2;5 were higher in ethylene-treated trembling aspen roots compared with non-treated roots under hypoxia. The increases in the expression levels of these aquaporins could potentially facilitate root water transport. The enhanced root water transport by ethylene was likely responsible for the increase in leaf gas exchange of the hypoxic plants. Conclusions Exogenous ethylene enhanced root water transport and the expression levels of PIP2;4 and PIP2;5 in hypoxic roots of trembling aspen. The results suggest that ethylene facilitates the aquaporin-mediated water transport in plants exposed to root hypoxia.

scholarly journals Genetic and physiological regulation of folate in pak choi (Brassica rapa subsp. Chinensis) germplasm

2020 ◽  
Vol 71 (16) ◽  
pp. 4914-4929
Author(s):  
M J I Shohag ◽  
Yanyan Wei ◽  
Jie Zhang ◽  
Ying Feng ◽  
Michael Rychlik ◽  
...  
Keyword(s):  
Brassica Rapa ◽  
Transcriptional Level ◽  
In Planta ◽  
Physiological Basis ◽  
Breeding Programs ◽  
Pak Choi ◽  
Physiological Regulation ◽  
The Difference ◽  
Folate Homeostasis ◽  
Living Organisms

Abstract Folates are one of the essential micronutrients for all living organisms. Due to inadequate dietary intake, folate deficiency remains prevalent in humans. Genetically diverse germplasms can potentially be used as parents in breeding programs and also for understanding the folate regulatory network. Therefore, we investigated the natural genetic diversity of folates and their physiological regulation in pak choi (Brassica rapa subsp. Chinensis) germplasm. The total folate concentration ranged from 52.7 μg 100 gFW–1 to 166.9 μg 100 gFW–1, with 3.2-fold variation. The main folate vitamer was represented by 5-CH3-H4folate, with 4.5-fold variation. The activities of GTP cyclohydrolase I and aminodeoxy chorismate synthase, the first step of folate synthesis, were high in high folate accessions and low in low folate accessions. Analysis of the transcription levels of 11 genes associated with folate metabolism demonstrated that the difference in folate concentrations may be primarily controlled at the post-transcriptional level. A general correlation between total folate and their precursors was observed. Folate diversity and chlorophyll content were tightly regulated through the methyl cycle. The diverse genetic variation in pak choi germplasm indicated the great genetic potential to integrate breeding programs for folate biofortification and unravel the physiological basis of folate homeostasis in planta.

Selenium foliar application alters patterns of glucosinolate hydrolysis products of pak choi Brassica rapa L. var. chinensis

2020 ◽  
Vol 273 ◽  
pp. 109614
Author(s):  
Muna A. Abdalla ◽  
Caroline A.C. Meschede ◽  
Karl H. Mühling
Keyword(s):  
Brassica Rapa ◽  
Foliar Application ◽  
Pak Choi ◽  
Hydrolysis Products

scholarly journals Transient physiological responses of planting frozen root plugs of Douglas-fir seedlings

2008 ◽  
Vol 38 (6) ◽  
pp. 1517-1525 ◽  
Author(s):  
M. Anisul Islam ◽  
Douglass F. Jacobs ◽  
Kent G. Apostol ◽  
R. Kasten Dumroese
Keyword(s):  
Physiological Responses ◽  
Net Photosynthesis ◽  
Hydraulic Conductance ◽  
Early Growth ◽  
Douglas Fir ◽  
Root Hydraulic Conductance ◽  
Short Term ◽  
Environmental Regimes ◽  
Dry Conditions ◽  
Growing Conditions

Short-term physiological responses of planting frozen (FR) and rapidly thawed (TR) root plugs of Douglas-fir ( Pseudotsuga menziesii (Mirb.) Franco) seedlings were examined through time series (0 h, 6 h, 12 h, 1 day, 3 days, and 7 days) measurements in two separate experiments: 10 °C day : 6 °C night, RH 75% and 30 °C day : 20 °C night, RH 50%, respectively. Net photosynthesis, transpiration, shoot water potential, and root hydraulic conductance were lower in FR compared with TR seedlings under both growing conditions. Magnitude of difference in root hydraulic conductance was higher under warm-dry conditions. Chlorophyll fluorescence (Fv/Fm) values were higher for TR than FR seedlings at 0 h, but similar thereafter for both growing conditions. Needle electrolyte leakage and chlorophyll content did not differ between FR and TR seedlings under both environmental regimes. Higher root O2 uptake was observed in FR seedlings in warm-dry conditions and in TR seedlings under cool-moist conditions. TR seedlings planted under warm-dry conditions had more flushed buds and new roots than FR seedlings, while no buds flushed for both FR and TR seedlings under cool-moist conditions. Comparatively higher photosynthesic rates in TR seedlings planted under warm-dry conditions likely contributed toward more new roots, which could be advantageous for survival and early growth.

scholarly journals The Grapevine Root-Specific Aquaporin VvPIP2;4N Controls Root Hydraulic Conductance and Leaf Gas Exchange under Well-Watered Conditions But Not under Water Stress

2012 ◽  
Vol 160 (2) ◽  
pp. 965-977 ◽  
Author(s):  
Irene Perrone ◽  
Giorgio Gambino ◽  
Walter Chitarra ◽  
Marco Vitali ◽  
Chiara Pagliarani ◽  
...  
Keyword(s):  
Water Stress ◽  
Gas Exchange ◽  
Leaf Gas Exchange ◽  
Hydraulic Conductance ◽  
Root Hydraulic Conductance

scholarly journals Metabolomic analysis reveals the interaction of primary and secondary metabolism in white, pale green, and green pak choi (Brassica rapa subsp. chinensis)

2021 ◽  
Vol 64 (1) ◽  
Author(s):  
Hyeon Ji Yeo ◽  
Seung-A Baek ◽  
Ramaraj Sathasivam ◽  
Jae Kwang Kim ◽  
Sang Un Park
Keyword(s):  
Secondary Metabolites ◽  
Brassica Rapa ◽  
High Performance ◽  
Reducing Power ◽  
Total Phenolic ◽  
Pak Choi ◽  
Primary And Secondary Metabolites ◽  
Chlorophyll Contents ◽  
Significant Difference ◽  
Pale Green

AbstractThis study aimed to comprehensively analyze primary and secondary metabolites of three different-colored (white, pale green, and green) pak choi cultivars (Brassica rapa subsp. chinensis) using gas chromatography attached with time-of-flight mass spectrometry (GC-TOFMS) and high-performance liquid chromatography (HPLC). In total, 53 primary metabolites were identified and subjected to partial least-squares discriminant analysis. The result revealed a significant difference in the primary and secondary metabolites between the three pak choi cultivars. In addition, 49 hydrophilic metabolites were detected in different cultivars. Total phenolic and glucosinolate contents were highest in the pale green and green cultivars, respectively, whereas total carotenoid and chlorophyll contents were highest in the white cultivar. Superoxide dismutase activity, 2,2-diphenyl-1-picrylhydraz scavenging, and reducing power were slightly increased in the white, pale green, and green cultivars, respectively. In addition, a negative correlation between pigments and phenylpropanoids was discovered by metabolite correlation analysis. This approach will provide useful information for the development of strategies to enhance the biosynthesis of phenolics, glucosinolates, carotenoids, and chlorophyll, and to improve antioxidant activity in pak choi cultivars. In addition, this study supports the use of HPLC and GC-TOFMS-based metabolite profiling to explore differences in pak choi cultivars.

scholarly journals Identification and Functional Characterization of a Cold-Related Protein, BcHHP5, in Pak-Choi (Brassica rapa ssp. chinensis)

2018 ◽  
Vol 20 (1) ◽  
pp. 93
Author(s):  
Jin Wang ◽  
Feiyi Huang ◽  
Xiong You ◽  
Xilin Hou
Keyword(s):  
Brassica Rapa ◽  
Abiotic Stresses ◽  
Quantitative Polymerase Chain Reaction ◽  
Functional Characterization ◽  
Regulation Mechanism ◽  
Pak Choi ◽  
Negative Effect ◽  
Polymerase Chain ◽  
Related Proteins

In plants, heptahelical proteins (HHPs) have been shown to respond to a variety of abiotic stresses, including cold stress. Up to the present, the regulation mechanism of HHP5 under low temperature stress remains unclear. In this study, BcHHP5 was isolated from Pak-choi (Brassica rapa ssp. chinensis cv. Suzhouqing). Sequence analysis and phylogenetic analysis indicated that BcHHP5 in Pak-choi is similar to AtHHP5 in Arabidopsis thaliana. Structure analysis showed that the structure of the BcHHP5 protein is relatively stable and highly conservative. Subcellular localization indicated that BcHHP5 was localized on the cell membrane and nuclear membrane. Furthermore, real-time quantitative polymerase chain reaction (RT-qPCR) analysis showed that BcHHP5 was induced to express by cold and other abiotic stresses. In Pak-choi, BcHHP5-silenced assay, inhibiting the action of endogenous BcHHP5, indicated that BcHHP5-silenced might have a negative effect on cold tolerance, which was further confirmed. All of these results indicate that BcHHP5 might play a role in abiotic response. This work can serve as a reference for the functional analysis of other cold-related proteins from Pak-choi in the future.

scholarly journals A comparison of the short-term kinetics of zinc metabolism in women during fasting and following a breakfast meal

1998 ◽  
Vol 80 (4) ◽  
pp. 363-370 ◽  
Author(s):  
Nicola M. Lowe ◽  
Leslie R. Woodhouse ◽  
Janet C. King
Keyword(s):  
Energy Content ◽  
Compartment Model ◽  
Zinc Metabolism ◽  
Short Term ◽  
Compartment System ◽  
Breakfast Meal ◽  
Physiological Importance ◽  
Two Compartment Model ◽  
Zn Concentration ◽  
Kinetics Of

The physiological importance and mechanism of the postprandial fall in plasma Zn concentration is not well understood. In order to gain further information on this apparent redistribution of plasma Zn, a stable isotope, 70Zn, was used to study the effect of a breakfast meal on plasma Zn kinetics. Nine women participated in two trials, a fasting trial and a breakfast-meal trial; five of the women participated in a third trial in which the energy content of the breakfast meal was doubled. At each trial, 0.1mg of 70Zn was infused intravenously, and the plasma disappearance of the isotope was analysed using a two-compartment model of Zn kinetics. Plasma Zn concentration fell significantly following the two trials in which the subjects were given meals, reaching low points that were 13 and 19 %, respectively, below concentrations at comparable times during the fasting trial. Kinetic analysis revealed that after the doubled breakfast meal there was a significant fall (P < 0.007) in the size of the most rapidly turning over Zn pool (pool (a)) from 2.90 (se 0.13)mg in the fasting state to 2.47 (se 0.14) mg postprandially. The fractional turnover rate of pool (a) to other extravascular Zn pools, i.e. outside the two-compartment system, was also significantly elevated after the doubled breakfast meal (P < 0.05). These results suggest that the decline in plasma Zn concentration following a meal is due to a redistribution of Zn from the plasma to other more slowly turning over extravascular pools that may be involved in the assimilation and metabolism of fuels following food intake.

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