Changes in Carbohydrate Metabolism in Plasmopara viticola-Infected Grapevine Leaves

The oomycete Plasmopara viticola is responsible for downy mildew, a severe grapevine disease. In infected grapevine leaves, we have observed an abnormal starch accumulation at the end of the dark period, suggesting modifications in starch metabolism. Therefore, several complementary approaches, including transcriptomic analyses, measurements of enzyme activities, and sugar quantification, were performed in order to investigate and to understand the effects of P. viticola infection on leaf starch and—to a larger extent—carbohydrate metabolism. Our results indicate that starch accumulation is associated with an increase in ADP-glucose pyrophosphorylase (AGPase) activity and modifications in the starch degradation pathway, especially an increased α-amylase activity. Together with these alterations in starch metabolism, we have observed an accumulation of hexoses, an increase in invertase activity, and a reduction of photosynthesis, indicating a source-to-sink transition in infected leaf tissue. Additionally, we have measured an accumulation of the disaccharide trehalose correlated to an increased trehalase gene expression and enzyme activity. Altogether, these results highlight a dramatic alteration of carbohydrate metabolism correlated with later stages of P. viticola development in leaves.

Download Full-text

Toward the Identification of Two Glycoproteins Involved in the Stomatal Deregulation of Downy Mildew–Infected Grapevine Leaves

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi-05-15-0115-r ◽

2015 ◽

Vol 28 (11) ◽

pp. 1227-1236 ◽

Cited By ~ 7

Author(s):

Christelle Guillier ◽

Magdalena Gamm ◽

Géraldine Lucchi ◽

Caroline Truntzer ◽

Delphine Pecqueur ◽

...

Keyword(s):

Downy Mildew ◽

Active Compound ◽

In Silico Analysis ◽

Plasmopara Viticola ◽

Stomatal Response ◽

Protein Fractionation ◽

Biochemical Assays ◽

Grapevine Leaves ◽

Infected Grapevine ◽

Silico Analysis

Stomata remain abnormally opened and unresponsive to abscisic acid in grapevine leaves infected by downy mildew. This deregulation occurs from 3 days postinoculation and increases concomitantly with leaf colonization by the pathogen. Using epidermal peels, we demonstrated that the active compound involved in this deregulation is located in the apoplast. Biochemical assays showed that the active compound present in the apoplastic fluids isolated from Plasmopara viticola–infected grapevine leaves (IAF) is a CysCys bridge-independent, thermostable and glycosylated protein. Fractionation guided assays based on chromatography coupled to stomatal response and proteomic analysis allowed the identification of both plant and pathogen proteins in the active fraction obtained from IAF. Further in silico analysis and discriminant filtrations based on the comparison between predictions and experimental indications lead to the identification of two Vitis vinifera proteins as candidates for the observed stomatal deregulation.

Download Full-text

Response of grapevine leaves to Plasmopara viticola infection by means of measurement of reflectance and fluorescence signals

Acta Universitatis Agriculturae et Silviculturae Mendelianae Brunensis ◽

10.11118/actaun201260080229 ◽

2012 ◽

Vol 60 (8) ◽

pp. 229-238 ◽

Cited By ~ 1

Author(s):

David Šebela ◽

Julie Olejníčková ◽

Anita Župčanová ◽

Radek Sotolář

Keyword(s):

Chlorophyll Fluorescence ◽

Leaf Tissue ◽

Plasmopara Viticola ◽

Fluorescence Induction ◽

Chlorophyll Fluorescence Induction ◽

Infected Leaf ◽

Acceptor Site ◽

Induction Kinetics ◽

Donor And Acceptor ◽

Infected Leaf Tissue

Response of grapevine leaf tissue naturally infected byPlasmopara viticolain field was measured by means of chlorophyll fluorescence and reflectance signals. Three susceptible grapevine varieties (Cabernet Sauvignon, Pinot Blanc and Pinot Gris) were used in this study. Since the infection impairs photosynthetic activity, distribution of FV/FMparameter (maximum quantum yield of Photosystem II) over the leaf was effective to discriminate healthy and naturally infected leaf tissue. FV/FMwas reduced ~ 25% in all infected leaf parts. Infected leaf spots expressed significantly altered chlorophyll fluorescence induction kinetics expressing much slower electron transport rate both on donor and acceptor site of PSII. Vegetation reflectance indices followed the variations in pigment content after the fungal infection. R750/R700 (R2= 0.877) and CRI (carotenoid reflectance index; R2=0.735) were the most potent to follow changes in chlorophylls and carotenoids contents, respectively. Infected leaf tissue exhibited decrease in chlorophyll a (~50 %) as well as carotenoids (~70%). We conclude that combination of chlorophyll fluorescence and reflectance measurements can be used as an effective non-invasive tool for an early detection ofPlasmopara viticolain field as well as for estimation of the level of infection.

Download Full-text

Starch metabolism in the fructan-grasses: Patterns of starch accumulation in excised leaves of Lolium temulentum L.

Journal of Plant Physiology ◽

10.1078/0176-1617-00644 ◽

2002 ◽

Vol 159 (3) ◽

pp. 293-305 ◽

Cited By ~ 21

Author(s):

Andrew J. Cairns ◽

Alan Cookson ◽

Barry J. Thomas ◽

Lesley B. Turner

Keyword(s):

Starch Accumulation ◽

Starch Metabolism ◽

Lolium Temulentum

Download Full-text

Isolation of Plasmopara viticola from Grapevine Leaves

Proceedings ◽

10.3390/proceedings2019029034 ◽

2019 ◽

Vol 29 (1) ◽

pp. 34

Author(s):

Camelia Ungureanu ◽

Liliana Cristina Soare ◽

Diana Vizitiu ◽

Mirela Calinescu ◽

Irina Fierascu ◽

...

Keyword(s):

Downy Mildew ◽

Plasmopara Viticola ◽

Grapevine Downy Mildew ◽

Grapevine Leaves ◽

Downy Mildew Disease

In order to test some biofungicides, the isolation of Plasmopara viticola was carried out.Plasmopara viticola is a fungus that causes the grapevine downy mildew disease [...]

Download Full-text

Transcriptome Analysis and Identification of Genes Associated with Starch Metabolism in Castanea henryi Seed (Fagaceae)

International Journal of Molecular Sciences ◽

10.3390/ijms21041431 ◽

2020 ◽

Vol 21 (4) ◽

pp. 1431 ◽

Cited By ~ 2

Author(s):

Bin Liu ◽

Ruqiang Lin ◽

Yuting Jiang ◽

Shuzhen Jiang ◽

Yuanfang Xiong ◽

...

Keyword(s):

Seed Germination ◽

Candidate Genes ◽

Starch Content ◽

Sugar Content ◽

Soluble Sugar ◽

Starch Accumulation ◽

Transcriptional Level ◽

Potential Candidate ◽

Starch Metabolism ◽

Carbohydrate Storage

Starch is the most important form of carbohydrate storage and is the major energy reserve in some seeds, especially Castanea henryi. Seed germination is the beginning of the plant’s life cycle, and starch metabolism is important for seed germination. As a complex metabolic pathway, the regulation of starch metabolism in C. henryi is still poorly understood. To explore the mechanism of starch metabolism during the germination of C. henryi, we conducted a comparative gene expression analysis at the transcriptional level using RNA-seq across four different germination stages, and analyzed the changes in the starch and soluble sugar contents. The results showed that the starch content increased in 0–10 days and decreased in 10–35 days, while the soluble sugar content continuously decreased in 0–30 days and increased in 30–35 days. We identified 49 candidate genes that may be associated with starch and sucrose metabolism. Three ADP-glucose pyrophosphorylase (AGPase) genes, two nucleotide pyrophosphatase/phosphodiesterases (NPPS) genes and three starch synthases (SS) genes may be related to starch accumulation. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to validate the expression levels of these genes. Our study combined transcriptome data with physiological and biochemical data, revealing potential candidate genes that affect starch metabolism during seed germination, and provides important data about starch metabolism and seed germination in seed plants.

Download Full-text

Acid Invertase Activity during Senescence of Excised Leaf Tissue of Lolium temulentum

Zeitschrift für Pflanzenphysiologie ◽

10.1016/s0044-328x(78)80227-x ◽

1978 ◽

Vol 90 (1) ◽

pp. 79-84 ◽

Cited By ~ 14

Author(s):

C.J. Pollock ◽

E.J. Lloyd

Keyword(s):

Leaf Tissue ◽

Invertase Activity ◽

Acid Invertase ◽

Lolium Temulentum

Download Full-text

Growth-inhibiting Fungicides Affect Detection of Phytophthora ramorum from Infected Foliage and Roots

Plant Health Progress ◽

10.1094/php-rs-12-0124 ◽

2014 ◽

Vol 15 (1) ◽

pp. 36-40 ◽

Cited By ~ 1

Author(s):

Nina Shishkoff

Keyword(s):

Root Colonization ◽

Leaf Tissue ◽

Phytophthora Ramorum ◽

Infected Leaf ◽

Inoculum Production ◽

Affect Detection ◽

Flow Through ◽

Whole Plants ◽

Infected Leaf Tissue ◽

Growth Inhibiting

Growth-inhibiting fungicides are used routinely to control common and regulated Oomycete pathogens. This study investigated whether such fungicides could affect detection of Phytophthora ramorum from plant tissue, both foliage and roots. Whole plants of Rhododendron × ‘Cunningham's White’ were inoculated with P. ramorum and treated 3 days later with fosetyl-Al, mefenoxam, or propamocarb. The foliage was sampled over time to see if fungicides prevented successful culturing of the pathogen from infected leaf tissue or interfered with detection using real-time PCR or ELISA. Mefenoxam significantly reduced the ability to culture the pathogen from leaves for the first 6 weeks while recovery from leaves treated with other fungicides did not differ from water-treated controls; detection using PCR or ELISA was not affected by fungicide application. The roots of Viburnum cuttings were inoculated with P. ramorum and then treated 4 days later with fosetyl-Al, mefenoxam, or propamocarb. The amount of inoculum in flow through water samples taken weekly for 5 weeks was quantified and percent root colonization determined at the end of the experiment. Propamocarb had no effect on inoculum production or root infection, while viable inoculum production was significantly decreased in fosetyl-Al- or mefenoxam-treated plants over 5 weeks, and root colonization was significantly decreased. Accepted for publication 23 January 2014. Published 18 March 2014.

Download Full-text

POSSIBILITIES FOR INTER- AND INTRACELLULAR TRANSLOCATION OF SOME ICOSAHEDRAL PLANT VIRUSES

The Journal of Cell Biology ◽

10.1083/jcb.40.3.814 ◽

1969 ◽

Vol 40 (3) ◽

pp. 814-823 ◽

Cited By ~ 59

Author(s):

G. A. de Zoeten ◽

G. Gaard

Keyword(s):

Leaf Tissue ◽

Plant Viruses ◽

Infected Leaf ◽

Mesophyll Cells ◽

Low Concentrations ◽

Infected Cells ◽

Virus Research ◽

High Concentrations ◽

Pore Complexes ◽

Intracellular Translocation

Southern bean mosaic virus (SBMV) and Tomato ringspot virus (TomRV) were compared with regard to possible ways of inter- and intracellular translocation. The pore complexes in the nuclear membranes of nuclei in leaf palisade and mesophyll cells of several plant species commonly used in plant virus research were studied. The pore structure resembled that earlier described. The diameter of the pores was great enough to allow icosahedral plant viruses between 25 and 30 mµ wide to move through. SBMV occurred in noncrystalline form in nuclei of infected cells. Although this virus forms paracrystalline structures when partially purified, no virus crystals were seen in the cytoplasm of cells containing high concentrations of SBMV. It was established that this virus could move through nuclear pores. TomRV was found in infected leaf tissue in low concentrations. This virus showed a tendency to crystallize even when present in low concentrations. TomRV was observed only in the cytoplasm, not in nuclei. This virus was present in plasmodesmata, indicating the possibility of cell to cell translocation of whole particles through these structures.

Download Full-text