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.

Correlation of Grassy Lake and Cedar Lake ambers using infrared spectroscopy, stable isotopes, and palaeoentomology

2008 ◽  
Vol 45 (9) ◽  
pp. 1061-1082 ◽  
Author(s):  
Ryan C. McKellar ◽  
Alexander P. Wolfe ◽  
Ralf Tappert ◽  
Karlis Muehlenbachs
Keyword(s):  
Stable Isotopes ◽  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Late Cretaceous ◽  
Western Canada ◽  
Long Distance ◽  
Geochemical Fingerprinting ◽  
Long Distance Transport ◽  
Distance Transport

The Late Cretaceous Grassy Lake and Cedar Lake amber deposits of western Canada are among North America’s most famous amber-producing localities. Although it has been suggested for over a century that Cedar Lake amber from western Manitoba may be a secondary deposit having originated from strata in Alberta, this hypothesis has not been tested explicitly using geochemical fingerprinting coupled to comparative analyses of arthropod faunal content. Although there are many amber-containing horizons associated with Cretaceous coals throughout Alberta, most are thermally mature and brittle, thus lacking the resilience to survive long distance transport while preserving intact biotic inclusions. One of the few exceptions is the amber found in situ at Grassy Lake. We present a suite of new analyses from these and other Late Cretaceous ambers from western Canada, including stable isotopes (H and C), Fourier transform infrared (FTIR) spectra, and an updated faunal compendium for the Grassy and Cedar lakes arthropod assemblages. When combined with amber’s physical properties and stratigraphic constraints, the results of these analyses confirm that Cedar Lake amber is derived directly from the Grassy Lake amber deposit or an immediate correlative equivalent. This enables the palaeoenvironmental context of Grassy Lake amber to be extended to the Cedar Lake deposit, making possible a more inclusive survey of Cretaceous arthropod faunas.

scholarly journals Identification of miRNA precursors in the phloem of Cucurbita maxima

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e8269 ◽  
Author(s):  
Eugeny Tolstyko ◽  
Alexander Lezzhov ◽  
Andrey Solovyev
Keyword(s):  
Cell Fate ◽  
Positional Information ◽  
Mature Mirnas ◽  
Inorganic Phosphorus ◽  
Pcr Analysis ◽  
Cucurbita Maxima ◽  
Phloem Exudate ◽  
Long Distance ◽  
Long Distance Transport ◽  
Range Cell

Plant development and responses to environmental cues largely depend on mobile signals including microRNAs (miRNAs) required for post-transcriptional silencing of specific genes. Short-range cell-to-cell transport of miRNA in developing tissues and organs is involved in transferring positional information essential for determining cell fate. Among other RNA species, miRNAs are found in the phloem sap. Long-distance transport of miRNA via the phloem takes a part in regulation of physiological responses to changing environmental conditions. As shown for regulation of inorganic phosphorus and sulfate homeostasis, mature miRNAs rather than miRNAs precursors are transported in the phloem as signaling molecules. Here, a bioinformatics analysis of transcriptomic data for Cucurbita maxima phloem exudate RNAs was carried out to elucidate whether miRNA precursors could also be present in the phloem. We demonstrated that the phloem transcriptome contained a subset of C. maxima pri-miRNAs that differed from a subset of pri-miRNA sequences abundant in a leaf transcriptome. Differential accumulation of pri-miRNA was confirmed by PCR analysis of C. maxima phloem exudate and leaf RNA samples. Therefore, the presented data indicate that a number of C. maxima pri-miRNAs are selectively recruited to the phloem translocation pathway. This conclusion was validated by inter-species grafting experiments, in which C. maxima pri-miR319a was found to be transported across the graft union via the phloem, confirming the presence of pri-miR319a in sieve elements and showing that phloem miRNA precursors could play a role in long-distance signaling in plants.

scholarly journals Regulation of Sulfur Homeostasis in Mycorrhizal Maize Plants Grown in a Fe-Limited Environment

2020 ◽  
Vol 21 (9) ◽  
pp. 3249
Author(s):  
Styliani N. Chorianopoulou ◽  
Petros P. Sigalas ◽  
Niki Tsoutsoura ◽  
Anastasia Apodiakou ◽  
Georgios Saridis ◽  
...  
Keyword(s):  
Higher Plants ◽  
Expression Patterns ◽  
Soluble Form ◽  
Mycorrhizal Symbiosis ◽  
Sulfur Deprivation ◽  
Long Distance ◽  
Sulfate Anion ◽  
Long Distance Transport ◽  
Maize Plants ◽  
Distance Transport

Sulfur is an essential macronutrient for growth of higher plants. The entry of the sulfate anion into the plant, its importation into the plastids for assimilation, its long-distance transport through the vasculature, and its storage in the vacuoles require specific sulfate transporter proteins. In this study, mycorrhizal and non-mycorrhizal maize plants were grown for 60 days in an S-deprived substrate, whilst iron was provided to the plants in the sparingly soluble form of FePO4. On day 60, sulfate was provided to the plants. The gene expression patterns of a number of sulfate transporters as well as sulfate assimilation enzymes were studied in leaves and roots of maize plants, both before as well as after sulfate supply. Prolonged sulfur deprivation resulted in a more or less uniform response of the genes’ expressions in the roots of non-mycorrhizal and mycorrhizal plants. This was not the case neither in the roots and leaves after the supply of sulfur, nor in the leaves of the plants during the S-deprived period of time. It is concluded that mycorrhizal symbiosis modified plant demands for reduced sulfur, regulating accordingly the uptake, distribution, and assimilation of the sulfate anion.

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.

scholarly journals The identification and characterization of a testis-specific cDNA during spermatogenesis

2006 ◽  
Vol 11 (1) ◽  
Author(s):  
Ying Chen ◽  
Jiarui Hu ◽  
Ping Song ◽  
Wuming Gong
Keyword(s):  
Experimental Validation ◽  
Rna Binding ◽  
Pcr Analysis ◽  
Splicing Factors ◽  
Rt Pcr ◽  
Rich Domain ◽  
Pachytene Spermatocytes ◽  
Identification And Characterization

AbstractUsing bioinformatics and experimental validation, we obtained a cDNA (named srsf) which was exclusively expressed in the mouse testes. RT-PCR analysis showed that srsf mRNA was not expressed in the gonad during the sex determination period or during embryogenesis. In developing mouse tests, srsf expression was first detected on post-natal day 10, reached its highest level on day 23, and then reduced to and remained at a moderate level throughout adulthood. In situ hybridization analysis demonstrated that srsf mRNA was expressed in pachytene spermatocytes and round spermatids in the testes. The predicted protein contains one RNA-binding domain (RBD) and a serine-arginine rich domain (RS), which are characterized by some splicing factors of SR family members. These findings indicate that srsf may play a role during spermatogenesis.

Molecular identification of Ca2+-activated K+ channels in parotid acinar cells

2003 ◽  
Vol 284 (2) ◽  
pp. C535-C546 ◽  
Author(s):  
Keith Nehrke ◽  
Claire C. Quinn ◽  
Ted Begenisich
Keyword(s):  
Single Channel ◽  
Acinar Cells ◽  
Pcr Analysis ◽  
Rt Pcr ◽  
Channel Conductance ◽  
Single Channel Conductance ◽  
Parotid Acinar Cells ◽  
Large Conductance Channel ◽  
Intracellular Ca

We used molecular biological and patch-clamp techniques to identify the Ca2+-activated K+ channel genes in mouse parotid acinar cells. Two types of K+ channels were activated by intracellular Ca2+ with single-channel conductance values of 22 and 140 pS (in 135 mM external K+), consistent with the intermediate and maxi-K classes of Ca2+-activated K+ channels, typified by the mIK1 ( Kcnn4) and mSlo ( Kcnma1) genes, respectively. The presence of mIK1 mRNA was established in acinar cells by in situ hybridization. The electrophysiological and pharmacological properties of heterologously expressed mIK1 channels matched those of the native current; thus the native, smaller conductance channel is likely derived from the mIK1 gene. We found that parotid acinar cells express a single, uncommon splice variant of the mSlo gene and that heterologously expressed channels of this Slo variant had a single-channel conductance indistinguishable from that of the native, large-conductance channel. However, the sensitivity of this expressed Slo variant to the scorpion toxin iberiotoxin was considerably different from that of the native current. RT-PCR analysis revealed the presence of two mSlo β-subunits ( Kcnmb1 and Kcnmb4) in parotid tissue. Comparison of the iberiotoxin sensitivity of the native current with that of parotid mSlo expressed with each β-subunit in isolation and measurements of the iberiotoxin sensitivity of currents in cells from β1 knockout mice suggest that parotid acinar cells contain approximately equal numbers of homotetrameric channel proteins from the parotid variant of the Slo gene and heteromeric proteins composed of the parotid Slo variant in combination with the β4-subunit.

scholarly journals Up-regulation of Per1 expression by estradiol and progesterone in the rat uterus

2007 ◽  
Vol 194 (3) ◽  
pp. 511-519 ◽  
Author(s):  
Pei-Jian He ◽  
Masami Hirata ◽  
Nobuhiko Yamauchi ◽  
Masa-aki Hattori
Keyword(s):  
Stromal Cells ◽  
Clock Genes ◽  
Staining Intensity ◽  
Reproductive Organ ◽  
Pcr Analysis ◽  
Rt Pcr ◽  
Rat Uterus ◽  
Ovarian Steroids ◽  
Direct Regulation

It has been established that estrogen can alter circadian rhythms in behavior and endocrine physiology in rodents. The uterus is a reproductive organ that is critically dependent on regulation by ovarian steroids. Here, we examined the expression of Per1 in different compartments of the uterus, and explored whether the ovarian steroids could regulate Per1 expression employing ovariectomized rat uterus. RT-PCR analysis showed that Per1 was cyclically expressed in the uterus. As revealed by in situ hybridization, the staining intensity of Per1 mRNA was stronger at ZT 8 than at ZT 0 in the uterine luminal epithelium (LE), stroma (S), and myometrium (M) compartments, but was not changed in the glandular epithelium (GE). Both in situ hybridization and immunofluorescence analyses revealed that estradiol (E2) administration induced high expression of Per1 in the LE, GE, and M, and less expression in the S compartment. Progesterone (P4) treatment resulted in an obvious enhancement of Per1 expression in the LE, GE, and S, but unchanged in the M compartment. Furthermore, the E2- and P4-activated Per1 expression was significantly repressed by their respective antagonists, ICI182 780 and RU486. These findings were further supported by RT-PCR analysis of Per1 expression in cultured uterine stromal cells. Collectively, the present data indicate that E2 and P4 might be involved in modification of circadian rhythm via direct regulation of the expression of clock genes.

scholarly journals Occurrence of Two Distinct Urotensin II-Related Peptides in Zebrafish Provides New Insight into the Evolutionary History of the Urotensin II Gene Family

Endocrinology ◽  
2011 ◽  
Vol 152 (6) ◽  
pp. 2330-2341 ◽  
Author(s):  
Caroline Parmentier ◽  
Emilie Hameury ◽  
Christophe Dubessy ◽  
Feng B. Quan ◽  
Damien Habert ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Close Contact ◽  
Ventral Side ◽  
Pcr Analysis ◽  
Urotensin Ii ◽  
Rt Pcr ◽  
History Of ◽  
The Brain ◽  
Insight Into

The urotensin II (UII) family is currently known to consist of two paralogous peptides, namely UII and UII-related peptide (URP). In contrast to UII, which has been identified in all vertebrate classes so far, URP has only been characterized in tetrapods. We report here the occurrence of two distinct URP genes in teleosts, which we have named URP1 and URP2. Synteny analysis revealed that teleost URP1 and URP2 genes and tetrapod URP genes represent three distinct paralog genes that, together with the UII gene, probably arose from the two rounds of tetraploidization, which took place early in vertebrate evolution. The absence of URP in fish indicates that the corresponding gene has been lost in the teleost lineage, whereas it is likely that both the URP1 and URP2 genes have been lost in the tetrapod lineage. Quantitative RT-PCR analysis revealed that the URP2 gene is mainly expressed in the spinal cord and the brain in adult zebrafish. In situ hybridization experiments showed that in zebrafish embryos, URP2 mRNA-containing cells are located in the floor plate of the neural tube. In adult, URP2-expressing cells occur in close contact with the ventral side of the ependymal canal along the whole spinal cord, whereas in the brain, they are located below the fourth ventricle. These URP-expressing cells may correspond to cerebrospinal fluid-contacting neurons. In conclusion, our study reveals the occurrence of four distinct UII paralogous systems in vertebrates that may exert distinct functions, both in tetrapods and teleosts.

scholarly journals Testing the Münch hypothesis of long distance phloem transport in plants

eLife ◽  
2016 ◽  
Vol 5 ◽  
Author(s):  
Michael Knoblauch ◽  
Jan Knoblauch ◽  
Daniel L Mullendore ◽  
Jessica A Savage ◽  
Benjamin A Babst ◽  
...  
Keyword(s):  
Strong Support ◽  
Sieve Tube ◽  
Phloem Transport ◽  
Plant Tissues ◽  
Long Distance ◽  
Pressure Flow ◽  
Long Distance Transport ◽  
Sieve Tubes ◽  
Distance Transport ◽  
Source And Sink

Long distance transport in plants occurs in sieve tubes of the phloem. The pressure flow hypothesis introduced by Ernst Münch in 1930 describes a mechanism of osmotically generated pressure differentials that are supposed to drive the movement of sugars and other solutes in the phloem, but this hypothesis has long faced major challenges. The key issue is whether the conductance of sieve tubes, including sieve plate pores, is sufficient to allow pressure flow. We show that with increasing distance between source and sink, sieve tube conductivity and turgor increases dramatically in Ipomoea nil. Our results provide strong support for the Münch hypothesis, while providing new tools for the investigation of one of the least understood plant tissues.

scholarly journals Characterization of a vacuolar sucrose transporter, HbSUT5, from Hevea brasiliensis: involvement in latex production through regulation of intracellular sucrose transport in the bark and laticifers

2019 ◽  
Author(s):  
xiangyu long ◽  
Heping Li ◽  
Jianghua Yang ◽  
Lusheng Xin ◽  
Bin He ◽  
...  
Keyword(s):  
Hevea Brasiliensis ◽  
Higher Plants ◽  
Transcript Level ◽  
Active Role ◽  
Sucrose Transporter ◽  
Sucrose Transport ◽  
Long Distance ◽  
Rubber Biosynthesis ◽  
Long Distance Transport ◽  
Latex Production

Abstract Background: Sucrose (Suc), as the precursor molecule for rubber biosynthesis in Hevea brasiliensis, is transported via phloem-mediated long-distance transport from leaves to laticifers in trunk bark, where latex (cytoplasm of laticifers) is tapped for rubber. Suc transporters (SUTs) play important roles during various steps of Suc transport in higher plants. Results: In our previous report, six SUT genes have been cloned in Hevea tree, among which HbSUT3 has been verified to play an active role in Suc loading to the laticifers. In this study, another latex-abundant SUT isoform, HbSUT5, with expressions only inferior to HbSUT3 was characterized especially for its roles in latex production. Both phylogenetic analysis and subcellular localization identify HbSUT5 as a SUT4-clade (=type III) vacuolar membrane SUT, suggesting its potential participation in Suc exchange between lutoids (polydispersed microvacuoles) and cytosol in latex. Suc uptake assay in yeast identifies HbSUT5 as a typical Suc-H+ symporter, but the high affinity of HbSUT5 for Suc (Km = 2.03 mM at pH 5.5) and its similar efficiency in transporting maltose making it a peculiar SUT under the SUT4-clade. At the transcript level, HbSUT5 is abundantly and preferentially expressed in Hevea barks. It is contrary to HbSUT3 that the transcripts of HbSUT5 are obviously decreased both in Hevea latex and bark during the treatments of tapping and ethephon, indicating it counteracts the yield-stimulating effects of two treatments. Conclusions: A vacuolar sucrose transporter, HbSUT5, may play an important role in Suc exchange between lutoids (polydispersed vacuoles) and latex in laticifers. It is better to understand that the whole HbSUT family regulate and control Suc accumulation in laticifers, influencing rubber yield formation in Hevea.

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