Peroxidase Isoenzyme Patterns in Cell Cultures derived from Cotyledon, Stem, Leaf and Fruit from Grapevine (Vitis vinifera cv. Monastrell)

The expression of peroxidase isoenzymes capable of oxidizing4-hydroxystilbenes was studied during the establishment of cellcultures derived from different tissues (cotyledon, stem, leafand fruit) of Vitis vinifera cv. Monastrell vines. This wascarried out in order to elucidate whether different tissuesof the same plant maintain persistent tissue-specific patternsof gene expression during in vitro culture or whether in vitrocultures are characterized by identical patterns of gene expressionirrespective of the tissue's origin. The results illustratedthat both the isozyme patterns and the substrate specificityof the peroxidase activity secreted to the medium are analogousfor the profile of acidic (Prx A) and basic (Prx B) peroxidaseisoenzymes, only quantitative differences being shown in theneutral peroxidase isoenzyme (Prx N) pattern. These resultssuggest that in vitro cultures of grapevines are characterizedby similar patterns of gene expression, no matter what theirtissue of origin.Copyright 1995, 1999 Academic Press Grapevine, vitis vinifera, cell cultures, 4-hydroxystilbene oxidizing peroxidase isoenzyme, substrate specificity     

Effect of Grapevine Leafroll on the Photosynthesis of Field Grown Grapevine Plants (Vitis vinifera L. cv. Lagrein)

We have studied the effect of grapevine leafroll infection on some features of the thylakoids from field grown grapevine (Vitis vinifera L.) leaves. Changes in photosynthetic pigments, soluble proteins, ribulose‐1,5‐bisphosphate carboxylase (RuBP), nitrate reductase, photosynthetic activities and thylakoid membrane proteins were investigated. The level of total chlorophyll (Chl) and carotenoids were reduced in virus‐infected leaves. Similar results were also observed for soluble proteins and RuBP case activity. The in vivo nitrate reductase activity was significantly reduced in infected leaves. Virus infection considerably decreased leaf net photosynthetic rate (P_n), stomatal conductance (g_s) and transpiration rate (E) in grapevine leaves. When various photosynthetic activities were followed in isolated thylakoids, virus infection caused marked inhibition of whole chain and photosystem (PS) II activity while the inhibition of PSI activity was only marginal. The artificial exogenous electron donors, diphenyl carbazide and hydroxylamine (NH₂OH) significantly restored the loss of PSII activity in infected leaves. The same results were obtained when F_v/F_m was evaluated by Chl fluorescence measurements. The marked loss of PSII activity in infected leaves could be due to the loss of 47, 43, 33, 28–25, 23 and 17 kDa polypeptides. It is concluded that virus infection inactivates the donor side of PSII. This conclusion was confirmed by immunological studies showing that the content of the 33 kDa protein of the water‐splitting complex was diminished significantly in infected leaves.     

Analysis of Glucocerebrosides of Rye (Secale cereale L. cv Puma) Leaf and Plasma Membrane

Glucocerebrosides of whole rye (Secale cerale L. cv Puma) leaf and plasma membrane were analyzed using gas chromatography-mass spectrometry and gas chromatography following hydrolysis or as intact molecules purified by reverse-phase high performance liquid chromatography. Fatty acids of acid-hydrolyzed leaf and plasma membrane glucocerebrosides consisted of >98 weight percent saturated and monounsaturated 2-hydroxy fatty acids which contained 16 to 26 carbon atoms. The major fatty acids detected were 2-hydroxynervonic acid (24:1h), 2-hydroxylignoceric acid (24:0h), 2-hydroxyerucic acid (22:1h), and 2-hydroxybehenic acid (22:0h). Long-chain bases of alkaline-hydrolyzed glucocerebrosides consisted primarily of cis-trans isomers of the trihydroxy base 4-hydroxysphingenine (t18:1) and the dihydroxy base sphingadienine (d18:2) with lesser amounts of 4-hydroxysphinganine (t18:0) and isomers of sphingenine (d18:1). Intact, underivatized glucocerebroside molecular species of rye leaf and plasma membrane were separated into more than 30 molecular species using reverse-phase HPLC. The molecular species composition of leaf and plasma membrane were quantitatively and qualitatively similar. The major molecular species was 24:1h-t18:1 which constituted nearly 40 weight percent of leaf and plasma membrane extracts. Several other species including 22:1h-t18:1, 24:1h-t18:1 (isomer), 22:0h-t18:1, 24:1h-d18:2, and 24:0h-t18:1 each comprised 4 to 8% of the total. It is anticipated that the high performance liquid chromatography procedure developed in this study to separate intact, underivatized lipid molecular species will be useful in future studies of the physical properties and biosynthesis of plant glucocerebrosides.     

葡萄实生树阶段转变过程中的内源多胺含量变化

用高效液相色谱法测定二年生巨峰葡萄自然实生树不同节位叶片、芽、韧皮部中内源多胺含量的结果表明,随着节位的升高,在3种组织中的腐胺(Put)和亚精胺(Spd)含量增加,21～25节腐胺增加幅度最大,自21节起亚精胺含量陡增;21～25节叶片中的精胺(Spm)含量出现高峰.说明21节左右可能是童性消失进入生殖生长期的临界点.     

Somatic Embryos and Plantlets from an Ancient Clone of the Grapevine (cv. Cabernet-Sauvignon) by Apomixis in vitro

Plantlets were produced by induction of nucellar embryony (apomixis)in isolated unfertilized ovules of a non-apomictic plant—thegrapevine (Vitis vinifera L. cv. Cabernet-Sauvignon). Ovulesgrown in liquid culture with benzyladenine (5–10 µM)and ß-naphthoxyacetic acid (5–25 µM) formeda nucellar callus which gave rise to somatic embryos. For growthof plantlets the embryos were transferred to an agar mediumcontaining gibberellic acid (1 µM) and 2-isopentenyladenine(5 µM). This is the first report of somatic embryo formationin a cultivar of a temperate fruit.     

First Detection of Stolbur Phytoplasma in Grapevines (Vitis vinifera cv. Merlot) Affected with Grapevine Yellows in Bulgaria

Between 2003 and 2005, a survey was conducted throughout the grape‐growing regions of Bulgaria to identify possible infection with grapevine yellows diseases, especially Flavescence dorée (FD). The samples were checked for phytoplasmas and viruses inducing similar symptoms in the Central Laboratory for Plant Quarantine. To confirm stolbur phytoplasma infection of grapevine, a multiplex nested‐PCR assay for direct detection of FD and stolbur phytoplasmas was used. Infection of grapevine with phytoplasma was detected. The disease is very common disease in Bulgaria on tomatoes, potatoes and other crops. Monitoring is being continued. This is the first report of phytoplasma‐infected grapevine in Bulgaria.     

Quantification of Apoplastic Potassium Content by Elution Analysis of Leaf Lamina Tissue from Pea (Pisum sativum L. cv Argenteum)

K⁺ content and concentration within the apoplast of mesophyll tissue of pea (Pisum sativum L., cv Argenteum) leaflets were determined using an elution procedure. Following removal of the epidermis, a 1 centimeter (inside diameter) glass cylinder was attached to the exposed mesophyll tissue and filled with 5 millimolar CaCl₂ solution (1°C). From time-course curves of cumulative K⁺ diffusion from the tissue, the amount of K⁺ of extracellular origin was estimated. Apoplastic K⁺ contents for leaves from plants cultured in nutrient solution containing 2 or 10 millimolar K⁺ were found to range from 1 to 4.5 micromoles per gram fresh weight, comprising less than 3% of the total K⁺ content within the lamina tissue. Assuming an apoplastic solution volume of 0.04 to 0.1 milliliters per gram fresh weight and a Donnan cation exchange capacity of 2.63 micromoles per gram fresh weight (experimentally determined), the K⁺ concentration within apoplastic solution was estimated at 2.4 to 11.8 millimolar. Net movement of Rb⁺ label from the extracellular compartment within mesophyll tissue into the symplast was demonstrated by pulse-chase experiments. It was concluded that the mesophyll apoplast in pea has a relatively low capacitance as an ion reservoir. Apoplastic K⁺ content was found to be highly sensitive to changes in xylem solution concentration.     

Transcriptomic Analysis of Human Retinal Surgical Specimens Using jouRNAl

Retinal detachment (RD) describes a separation of the neurosensory retina from the retinal pigmented epithelium (RPE). The RPE is essential for normal function of the light sensitive neurons, the photoreceptors. Detachment of the retina from the RPE creates a physical gap that is filled with extracellular fluid. RD initiates cellular and molecular adverse events that affect both the neurosensory retina and the RPE since the physiological exchange of ions and metabolites is severely perturbed. The consequence for vision is related to the duration of the detachment since a rapid reapposition of the two tissues results in the restoration of vision ¹. The treatment of RD is exclusively surgical. Removal of vitreous gel (vitrectomy) is followed by the removal non essential part of the retina around the detached area to favor retinal detachment. The removed retinal specimens are res nullius (nothing) and consequently normally discarded. To recover RNA from these surgical specimens, we developed the procedure jouRNAl that allows RNA conservation during the transfer from the surgical block to the laboratory. We also standardized a protocol to purify RNA by cesium chloride ultracentrifugation to assure that the purified RNAs are suitable for global gene expression analysis. The quality of the RNA was validated both by RT-PCR and microarray analysis. Analysis of the data shows a simultaneous involvement of inflammation and photoreceptor degeneration during RD.     

Tomato (Lycopersicon esculentum cv. Pik-Red) Leaf Carboxypeptidase: Identification, N-terminal Sequence, Stress-Regulation, and Specific Localization in the Paraveinal Mesophyll Vacuoles

Wounding of tomato (Lycopersicon esculentum L.) leaves causessystemic induction of a serine-type carboxypeptidase activity.We find this activity to be present in several isoforms. Antibodiesraised against the leaf carboxypeptidase inhibited the enzymeactivity and the immunoprecipitates were resolved into a 69-kDapolypeptide and a doublet of 35/37-kDa proteins on SDS-PAGE.Immunoblot analysis of the leaf proteins also immunodecoratedthe 69-kDa and 35/37-kDa proteins. Amino acid sequence analysisof the amino-terminus of the tomato leaf 69-kDa carboxypeptidaseshowed it to be similar to the barley A-chain carboxypeptidaseI [Sorenson et al. (1986) Carlsberg Res. Commun. 51: 475], sharingAla as the N-terminus and the sequences, AlaProGln and LeuProGlyPhe.Superimposition of a chemical stress (copper treatment) on woundingapparently lowered wound-induced carboxypeptidase activity inthe leaf, suggesting that cupric ions might interact with thewound signal. Immunogold electron microscopy indicated thatthe leaf carboxypeptidase was specifically localized withinthe inclusions of vacuoles of vascular parenchyma cells. Incupric ion-treated tissues, carboxypeptidase was found redistributedto other parts of the cell, indicating that this treatment,but not wounding, causes general vacuolar membrane damage. ⁴Deceased.     

Detection of Biogenic Silica in Leaf Blade, Leaf Sheath, and Stem of Bermuda Grass (Cynodon dactylon) Using LIBS and Phytolith Analysis

Laser induced breakdown spectroscopy (LIBS) has been used to perform in situ analysis of major and minor elements present in the different parts of the Bermuda grass (Cynodon dactylon). In situ, point detection/analysis of the elements in plants without any sample preparation has been demonstrated. LIBS spectra of the different parts (leaf blade, leaf sheath and stem) of fresh C. dactylon plant have been recorded to study the pattern of silica deposition in its different parts. Atomic lines of Si, Mg, Ca, C, Al, Zn, N, Sr, etc. have been observed in the LIBS spectra of the C. dactylon. A close observation of LIBS spectra of the different parts of the plants shows that silica concentration is greater in leaf blades than leaf sheaths and stems. The results obtained with LIBS analysis are also compared with the number density of phytoliths deposited in different parts of C. dactylon. It is observed that the highest silicified cell frequency is present in leaf blades followed by leaf sheaths and stems which is in close agreement with LIBS analysis.     

外源ALA对克瑞森无核葡萄叶片光合特性及果实品质的影响

以日光温室栽培的欧亚葡萄品种克瑞森无核为试验材料,在果实膨大期和始熟期采用不同浓度(50、100和150mg·L~(-1))5-氨基乙酰丙酸(ALA)喷施叶片和果穗,研究外源ALA处理对葡萄叶片光合特性、果实着色效果及果实品质的影响。结果表明:(1)各浓度ALA处理后葡萄叶片胞间CO_2浓度(Ci)、气孔导度(Gs)、蒸腾速率(Tr)、净光合速率(Pn)都有不同程度的增加,并以100mg·L~(-1) ALA处理效果最好。(2)50~150mg·L~(-1) ALA处理均能不同程度提高葡萄果皮花青素、叶绿素及类胡萝卜素含量,且各ALA处理的果实可溶性糖含量显著高于对照,但可滴定酸含量低于对照。(3)100和150mg·L~(-1) ALA处理能够显著改善果实成熟期的着色参数,且果实着色指数(CIRG)与花青素的积累呈现出良好的一致性。研究发现,在葡萄果实膨大期及始熟期喷施适宜浓度(100mg·L~(-1))ALA能够有效提高叶片光合性能,同时促进果实着色,显著改善果实外观色泽和果实品质。     

Genetic Evaluation of Schizophrenia Using the Illumina HumanExome Chip

Introduction

Schizophrenia is a genetically heterogeneous disorder that is associated with several common and rare genetic variants. As technology involved, cost advantages of chip based genotyping was combined with information about rare variants, resulting in the Infinium HumanExome Beadchip. Using this chip, a sample of 493 patients with schizophrenia or schizoaffective disorder and 484 healthy controls was genotyped.

Results

From the initial 242901 SNVs, 88306 had at least one minor allele and passed quality control. No variant reached genomewide-significant results (p<10^-8). The SNP with the lowest p-value was rs1230345 in WISP3 (p = 3.05*10⁻⁶), followed by rs9311525 in CACNA2D3 (p = 1.03*10⁻⁵) and rs1558557 (p = 3.85*10⁻⁰⁵) on chromosome 7. At the gene level, 3 genes were of interest: WISP3, on chromosome 6q21, a signally protein from the extracellular matrix. A second candidate gene is CACNA2D3, a regulator of the intracerebral calcium pathway. A third gene is TNFSF10, associated with p53 mediated apoptosis.