scholarly journals ABA flow modelling in Ricinus communis exposed to salt stress and variable nutrition

2016 ◽  
Vol 67 (18) ◽  
pp. 5301-5311 ◽  
Author(s):  
Andreas D Peuke
Keyword(s):  
Salt Stress ◽  
Nutrient Limitation ◽  
De Novo ◽  
Ricinus Communis ◽  
Leaf Growth ◽  
Xylem Sap ◽  
Phloem Transport ◽  
Phosphorus Limitation ◽  
Long Distance ◽  
N Source

Abstract In a series of experiments with Ricinus communis, abscisic acid (ABA) concentrations in tissues and transport saps, its de novo biosynthesis, long-distance transport, and metabolism (degradation) were affected by nutritional conditions, nitrogen (N) source, and nutrient limitation, or salt stress. In the present study these data were statistically re-evaluated, and new correlations presented that underpin the importance of this universal phytohormone. The biggest differences in ABA concentration were observed in xylem sap. N source had the strongest effect; however, nutrient limitation (particularly phosphorus limitation) and salt also had significant effects. ABA was found in greater concentration in phloem sap compared with xylem sap; however, the effect of treatment on ABA concentration in phloem was lower. In the leaves, ABA concentration was most variable compared with the other tissues. This variation was only affected by the N source. In roots, ABA was significantly decreased by nutrient limitation. Of the compartments in which ABA was quantified, xylem sap ABA concentration was most significantly correlated with leaf stomatal conductance and leaf growth. Additionally, ABA concentration in xylem was significantly correlated to that in phloem, indicating a 6-fold concentration increase from xylem to phloem. The ABA flow model showed that biosynthesis of ABA in roots affected the xylem flow of ABA. Moreover, ABA concentration in xylem affected the degradation of the phytohormone in shoots and also its export from shoots via phloem. The role of phloem transport is discussed since it stimulates ABA metabolism in roots.

scholarly journals Overproduction of ABA in rootstocks alleviates salinity stress in tomato shoots

2020 ◽  
Author(s):  
Cristina Martínez Andújar ◽  
Ascensión Martínez-Pérez ◽  
Alfonso Albacete Moreno ◽  
Purificación A Martínez-Melgarejo ◽  
Ian Dodd ◽  
...  
Keyword(s):  
Leaf Growth ◽  
Xylem Sap ◽  
Phloem Transport ◽  
Growth And Yield ◽  
Saline Stress ◽  
Reproductive Growth ◽  
Lateral Root Development ◽  
Solanum Lycopersicum L ◽  
Mesophyll Structure ◽  
Isopentenyl Adenine

To determine whether root-supplied ABA alleviates saline stress, tomato (Solanum lycopersicum L. cv. Sugar Drop) was grafted onto two independent lines overexpressing the SlNCED1 (9-cis-epoxycarotenoid dioxygenase) gene (NCED OE) and wild type rootstocks. After 200 days of salinity irrigation (EC = 3.5 dS m-1), plants with NCED OE rootstocks had 30% higher fruit yield, but root biomass and lateral root development was reduced. Although NCED OE rootstocks upregulated ABA-signalling (AREB, ATHB12), ethylene-related (ACCs, ERFs), aquaporin (PIPs) and stress-related (TAS14, KIN, LEA) genes, downregulation of PYL ABA receptors and signalling components (WRKYs), ethylene synthesis (ACOs) and auxin responsive factors occurred. Elevated SlNCED1 expression enhanced ABA levels in reproductive tissue while ABA catabolites accumulated in leaf and xylem sap suggesting homeostatic mechanisms. NCED OE also reduced xylem cytokinin transport to the shoot and stimulated foliar 2-isopentenyl adenine (iP) accumulation and phloem transport. Moreover, increased xylem gibberellin GA3 levels in growing fruit trusses was associated with enhanced reproductive growth. Improved photosynthesis without changes in stomatal conductance was consistent with hormone-mediated alteration of leaf growth and mesophyll structure, which combined with lower assimilate requirement in the roots and systemic changes in hormone balances could explain enhanced vigour, reproductive growth and yield under saline stress.

scholarly journals A comprehensive strategy for identifying long-distance mobile peptides in xylem sap

2015 ◽  
Vol 84 (3) ◽  
pp. 611-620 ◽  
Author(s):  
Satoru Okamoto ◽  
Takamasa Suzuki ◽  
Masayoshi Kawaguchi ◽  
Tetsuya Higashiyama ◽  
Yoshikatsu Matsubayashi
Keyword(s):  
Xylem Sap ◽  
Long Distance ◽  
Comprehensive Strategy

Root uptake and xylem transport of cadmium in wheat and triticale as affected by exogenous amino acids

2017 ◽  
Vol 68 (5) ◽  
pp. 415 ◽  
Author(s):  
K. Khodamoradi ◽  
A. H. Khoshgoftarmanesh ◽  
S. A. M. Mirmohammady Maibody
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Bread Wheat ◽  
Nutrient Solution ◽  
Metal Ion ◽  
Xylem Sap ◽  
Root Uptake ◽  
Plant Roots ◽  
Control Treatment ◽  
Long Distance

Organic acids exuded from plant roots significantly modify uptake and long-distance translocation of metals. Little is known about the effect of amino acids on metal ion uptake by plant roots. The present study investigated the effects of exogenous amino acids (histidine and glycine) in a nutrient solution on root uptake and xylem sap transport of cadmium (Cd) in triticale (× Triticosecale cv. Elinor) and bread wheat (Triticum aestivum L. cv. Back Cross Rushan). Plant seedlings were grown in a Cd-free modified Hoagland nutrient solution to which 1 µm Cd was added with either 50 µm histidine or 50 µm glycine or without amino acids at 4 weeks after germination. A control treatment consisted of a nutrient solution free of Cd and amino acids. In bread wheat, addition of histidine to the Cd-containing nutrient solution resulted in a higher operationally defined symplastic Cd fraction but a lower apoplastic one in the roots. In triticale, addition of either amino acid decreased the symplastic Cd fraction but increased the apoplastic one. Addition of histidine to the nutrient solution increased Cd concentration in wheat xylem sap but had no significant effect on Cd concentration in triticale xylem sap. Compared with the Cd-only treatment, the glycine-containing treatment led to significantly reduced Cd concentrations in xylem sap of both plant species. Wheat plants supplied with histidine and Cd accumulated greater amounts of Cd in their shoots than those supplied with Cd alone. Glycine had no significant effects on the Cd content of wheat shoots but decreased it in triticale shoots. Results indicate that the effects of amino acids on plant root uptake and xylem sap translocation of Cd depend on the type of amino acid supplemented. This finding is of great importance for selecting and/or breeding cultivars with Cd-toxicity tolerance.

scholarly journals Ericoid mycorrhizal diversity increases with soil age and progressive phosphorus limitation across a 4.1 million-year chronosequence

2020 ◽  
Author(s):  
Devin R. Leopold ◽  
Kabir G. Peay ◽  
Peter M. Vitousek ◽  
Tadashi Fukami
Keyword(s):  
Species Composition ◽  
Nutrient Limitation ◽  
Mycorrhizal Fungi ◽  
Fungal Diversity ◽  
Species Turnover ◽  
Phosphorus Limitation ◽  
Fungal Species ◽  
Direct Role ◽  
Ericoid Mycorrhizal Fungi ◽  
Soil Age

AbstractEricaceous plants rely on ericoid mycorrhizal fungi for nutrient acquisition. However, the factors that affect the composition and structure of these fungal communities remain largely unknown. Here, we use a 4.1-myr soil chronosequence in Hawaii to test the hypothesis that changes in nutrient availability with soil age determine the diversity and species composition of fungi associated with ericoid roots. We sampled roots of a native Hawaiian plant, Vaccinium calycinum, and used DNA metabarcoding to quantify changes in fungal diversity and species composition. We also used a fertilization experiment at the youngest and oldest sites to assess the importance of nutrient limitation. We found an increase in diversity and a clear pattern of species turnover across the chronosequence, driven largely by putative ericoid mycorrhizal fungi. Fertilization with nitrogen at the youngest site and phosphorus at the oldest site reduced total fungal diversity, suggesting a direct role of nutrient limitation. Our results also reveal the presence of novel fungal species associated with Hawaiian Ericaceae and suggest a greater importance of phosphorus availability for communities of ericoid mycorrhizal fungi than is generally assumed.

De novo sequencing, assembly, and analysis of Iris lactea var. chinensis roots’ transcriptome in response to salt stress

2018 ◽  
Vol 125 ◽  
pp. 1-12 ◽  
Author(s):  
Chunsun Gu ◽  
Sheng Xu ◽  
Zhiquan Wang ◽  
Liangqin Liu ◽  
Yongxia Zhang ◽  
...  
Keyword(s):  
Salt Stress ◽  
De Novo ◽  
De Novo Sequencing

Phloem long-distance transport of CmNACP mRNA: implications for supracellular regulation in plants

Development ◽  
1999 ◽  
Vol 126 (20) ◽  
pp. 4405-4419 ◽  
Author(s):  
R. Ruiz-Medrano ◽  
B. Xoconostle-Cazares ◽  
W.J. Lucas
Keyword(s):  
Higher Plants ◽  
Phloem Transport ◽  
The Body ◽  
Pcr Analysis ◽  
Rt Pcr ◽  
Long Distance ◽  
Rna Molecules ◽  
Long Distance Transport ◽  
Meristem Development

Direct support for the concept that RNA molecules circulate throughout the plant, via the phloem, is provided through the characterisation of mRNA from phloem sap of mature pumpkin (Cucurbita maxima) leaves and stems. One of these mRNAs, CmNACP, is a member of the NAC domain gene family, some of whose members have been shown to be involved in apical meristem development. In situ RT-PCR analysis revealed the presence of CmNACP RNA in the companion cell-sieve element complex of leaf, stem and root phloem. Longitudinal and transverse sections showed continuity of transcript distribution between meristems and sieve elements of the protophloem, suggesting CmNACP mRNA transport over long distances and accumulation in vegetative, root and floral meristems. In situ hybridization studies conducted on CmNACP confirmed the results obtained using in situ RT-PCR. Phloem transport of CmNACP mRNA was proved directly by heterograft studies between pumpkin and cucumber plants, in which CmNACP transcripts were shown to accumulate in cucumber scion phloem and apical tissues. Similar experiments were conducted with 7 additional phloem-related transcripts. Collectively, these studies established the existence of a system for the delivery of specific mRNA transcripts from the body of the plant to the shoot apex. These findings provide insight into the presence of a novel mechanism likely used by higher plants to integrate developmental and physiological processes on a whole-plant basis.

scholarly journals Overexpression of WAX INDUCER1/SHINE1 Gene Enhances Wax Accumulation under Osmotic Stress and Oil Synthesis in Brassica napus

2019 ◽  
Vol 20 (18) ◽  
pp. 4435 ◽  
Author(s):  
Ning Liu ◽  
Jie Chen ◽  
Tiehu Wang ◽  
Qing Li ◽  
Pengpeng Cui ◽  
...  
Keyword(s):  
Salt Stress ◽  
Brassica Napus ◽  
De Novo ◽  
Normal Growth ◽  
Acid Synthesis ◽  
Growth Conditions ◽  
Lipid Profiling ◽  
Intracellular Lipids ◽  
Oil Synthesis ◽  
Genes Encoding

WAX INDUCER1/SHINE1 (WIN1) belongs to the AP2/EREBP transcription factor family and plays an important role in wax and cutin accumulation in plants. Here we show that BnWIN1 from Brassica napus (Bn) has dual functions in wax accumulation and oil synthesis. Overexpression (OE) of BnWIN1 led to enhanced wax accumulation and promoted growth without adverse effects on oil synthesis under salt stress conditions. Lipid profiling revealed that BnWIN1-OE plants accumulated more waxes with elevated C29-alkanes, C31-alkanes, C28-alcohol, and C29-alcohol relative to wild type (WT) under salt stress. Moreover, overexpression of BnWIN1 also increased seed oil content under normal growth conditions. BnWIN1 directly bound to the promoter region of genes encoding biotin carboxyl carrier protein 1 (BCCP1), glycerol-3-phosphate acyltransferase 9 (GPAT9), lysophosphatidic acid acyltransferase 5 (LPAT5), and diacylglycerol acyltransferase 2 (DGAT2) involved in the lipid anabolic process. Overexpression of BnWIN1 resulted in upregulated expression of numerous genes involved in de novo fatty acid synthesis, wax accumulation, and oil production. The results suggest that BnWIN1 is a transcriptional activator to regulate the biosynthesis of both extracellular and intracellular lipids.

scholarly journals De novo transcriptome analysis of halotolerant bacterium Staphylococcus sp. strain P-TSB-70 isolated from East coast of India: In search of salt stress tolerant genes

PLoS ONE ◽  
2020 ◽  
Vol 15 (2) ◽  
pp. e0228199 ◽  
Author(s):  
Priyanka Das ◽  
Bijay Kumar Behera ◽  
Soumendranath Chatterjee ◽  
Basanta Kumar Das ◽  
Trilochan Mohapatra
Keyword(s):  
Salt Stress ◽  
Transcriptome Analysis ◽  
East Coast ◽  
De Novo ◽  
De Novo Transcriptome ◽  
East Coast Of India ◽  
Halotolerant Bacterium

scholarly journals Defenses against Virus and Vector: A Phloem-Biological Perspective on RTM- and SLI1-Mediated Resistance to Potyviruses and Aphids

Viruses ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 129 ◽  
Author(s):  
Karen J. Kloth ◽  
Richard Kormelink
Keyword(s):  
Virus Transmission ◽  
Phloem Transport ◽  
Long Distance ◽  
Functional Connection ◽  
Phloem Sap ◽  
Biological Perspective ◽  
Long Distance Transport ◽  
Underlying Mechanisms ◽  
Phloem Feeding ◽  
Distance Transport

Combining plant resistance against virus and vector presents an attractive approach to reduce virus transmission and virus proliferation in crops. Restricted Tobacco-etch virus Movement (RTM) genes confer resistance to potyviruses by limiting their long-distance transport. Recently, a close homologue of one of the RTM genes, SLI1, has been discovered but this gene instead confers resistance to Myzus persicae aphids, a vector of potyviruses. The functional connection between resistance to potyviruses and aphids, raises the question whether plants have a basic defense system in the phloem against biotic intruders. This paper provides an overview on restricted potyvirus phloem transport and restricted aphid phloem feeding and their possible interplay, followed by a discussion on various ways in which viruses and aphids gain access to the phloem sap. From a phloem-biological perspective, hypotheses are proposed on the underlying mechanisms of RTM- and SLI1-mediated resistance, and their possible efficacy to defend against systemic viruses and phloem-feeding vectors.

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