Project description:Since the roots of grapevine rootstocks have a direct contact with drying soil and has an important role in abiotic stimuli, any plasticity on the architecture of the rootstocks would enable grapevine varieties to a better respond to drought stress. However, genomics evidences behind the physiological responses of rootstocks under prolonged drought stress are poorly documented in the literature. In the current study, eight widely used hybrid grapevine rootstocks in viticulture were firstly grafted with sultana seedless and subjected to drought stress to test their physiological and biochemical responses. The results of experiment indicated that the roots of V.rupestris X V.berlandieri (110 R, 1103P, 140 Ru) rootstocks possessed much higher water content as well as non-structural carbohydrate and nitrogen concentrations compared to V.riparia X V.berlandieri (SO4, 5BB, 420A, 8B) and V.vinifera X V.berlandieri (41B) hybrids under drought. V.rupestris X V.berlandieri hybrids were also performed much higher root elongation performance under drought compared to other rootstock hybrids. Three rootstock varieties (110R, 5BB and 41B) having different pedigrees and root architectural responses to drought were also investigated at transcriptome level to find out gene regulation network behind differential physiological responses to drought. Transcriptome analysis revealed 2795, 1196 and 1612 differentially expressed transcripts for the roots of 110R, 5BB and 41B, respectively. The highest expression increases in 110R compared to other rootstocks were recorded for the transcripts functional in carbohydrate (SWEET14, CWINV) and nitrate/peptide (NRT1/ PTR FAMILY) transportation as well as osmoregulation (dehydrins, osmotins, LEAs and proline-glycine rich proteins) during drought. Higher induction of these genes in the roots of tolerant 110R genotype indicated importance of efficient uptake of carbohydrate and nitrogen source released from canopy under drought and preservation of water with osmotic regulation on the root elongation and drought tolerance of grapevines. Expression increases in several other pathogenesis related proteins, regulation of cell wall modification enzymes and activity of several secondary metabolites have been also associated to altered root architecture and drought tolerance in the grapevine rootstocks for the first time with the current study.
Project description:Grafting is a well-established practice for grapevine to facilitate propagation of productive and tolerant cultivars against several stress factors. It is also considered to be a suitable method for studying molecular aspects of root-to-shoot and/or shoot-to-root signaling events. So far, controlling only effect of rootstock over scion was investigated and root-to-shoot transcriptomic alterations were fallowed on the scions or graft interfaces. The objective of this study was to investigate transcriptomic and physiological influence of scion on the rootstock under drought stress. Therefore, drought tolerant 110R rootstock were firstly grafted with sultana seedless and tested under drought stress with its non-grafted counterpart. The results of treatment indicated that grafted 110R performed the highest root elongation under drought. We carried out a microarray based transcriptome analysis on the roots of grafted and non-grafted 110R to explain this drought derived interaction through scion-to-rootstock. The highest expression increase under drought was recorded for sugar (SWEET) and nitrate or di/tri-peptide (NRT1/ PTR FAMILY) transporter proteins. Expression level of these genes was more highly increased in grafted 110R than its non-grafted counterpart. This situation indicated their potential role in drought tolerance and scion/rootstock harmony. Overexpression of these transporters attributed to increased amount of released nutrient and nitrogen source from abscised leaves of sultana seedless under drought. Remobilization of these rich sources was suggested to chance transcriptomic response of rootstocks and enabled much better growth in grafted 110R. Other transcripts annotated to cell wall modification enzymes (chitinases), osmoregulator proteins (dehydrins, proline-glycine rich proteins) and secondary metabolites (stilbene synthase) were also more highly induced in grafted 110R. This is the first report indicating transcriptomic influence of scion on the grapevine rootstocks and representing the genes responsible in scion/rootstock harmony and drought tolerance.
Project description:The mechanisms of cellular and molecular adaptation of fungi to salinity have been commonly drawn from halotolerant strains, although some exceptions in basidiomycete fungi can be found. These studies have been conducted in settings where cells are subjected to stress, either hypo or hyperosmotic, which can be a confounding factor in describing physiological mechanisms related to salinity. Here, we have studied transcriptomic changes in Aspergillus sydowii, a halophilic species, when growing in three different salinity conditions (No salt, 0.5M and 2.0M NaCl). In this fungus salinity related responses occur under high salinity (2.0M NaCl) and not when cultured under optimal conditions (0.5M NaCl), suggesting that in this species, most of the mechanisms described for halophilic growth are a consequence of saline stress response and not an adaptation to saline conditions.
Project description:A set of grapevine R2R3 MYB repressors negatively regulate the expression of genes involved in different branches of the phenylpropanoid pathway For the genetic transformation of Vitis vinifera cv Maccabeu, the in vitro plantlets were grown for 90 days under light and temperature controlled. For overexpression of VvMYBC2-L3 in Vitis vinifera cv Maccabeu hairy roots, the cDNA sequence was transferred into the binary vector pH2GW7 by site-specific recombination. The construct was then inserted into Agrobacterium tumefaciens A4 by electroporation and used for the grapevine transformation. The induction and culture of transgenic HRs in grapevine were performed as described by Torregrosa and Bouquet (1997), with modifications reported in Cutanda-Perez et al. (2009).
Project description:Background: Abscisic acid (ABA) regulates various developmental processes and stress responses over both short (i.e. hours or days) and longer (i.e. months or seasons) time frames. To elucidate the transcriptional regulation of early responses of grapevine (Vitis vinifera) responding to ABA, different organs of grape (berries, shoot tips, leaves, roots and cell cultures) were treated with 10 μM (S)-(+)-ABA for 2 h. NimbleGen whole genome microarrays of Vitis vinifera were used to determine the effects of ABA on organ-specific mRNA expression patterns. Results: Transcriptomic analysis revealed 839 genes whose transcript abundances varied significantly in a specific organ in response to ABA treatment. No single gene exhibited the same changes in transcript abundance across all organs in response to ABA. The biochemical pathways affected by ABA were identified using the Cytoscape program with the BiNGO plug-in software. The results indicated that these 839 genes were involved in several biological processes such as flavonoid metabolism, response to reactive oxygen species, response to light, and response to temperature stimulus. ABA affected ion and water transporters, particularly in the root. The protein amino acid phosphorylation process was significantly overrepresented in shoot tips and roots treated with ABA. ABA affected mRNA abundance of genes (CYP707As, UGTs, and PP2Cs) associated with ABA degradation, conjugation, and the ABA signaling pathway. ABA also significantly affected the expression of several transcription factors (e.g. AP2/ERF, MYC/MYB, and bZIP/AREB). The greatest number of significantly differentially expressed genes was observed in the roots followed by cell cultures, leaves, berries, and shoot tips, respectively. Each organ had a unique set of gene responses to ABA. Conclusions: This study examined the short-term effects of ABA on different organs of grapevine. The responses of each organ were unique indicating that ABA signaling varies with the organ. Understanding the ABA responses in an organ-specific manner is crucial to fully understand hormone action and plant responses to water deficit. Shoot tips and berries samples were collected at the University of California, Davis, CA, USA (2010); cell culture samples were sampled at Oregon State University, OR, USA (2010); roots and leaf samples were collected at the University of Nevada, Reno, Reno, NV, USA (2011). Three independent experimental (and biological) replicates were harvested to compare between ABA-treated and untreated samples. Tissue was derived from Vitis vinifera L. cv. Cabernet Sauvignon.
Project description:Background: Abscisic acid (ABA) regulates various developmental processes and stress responses over both short (i.e. hours or days) and longer (i.e. months or seasons) time frames. To elucidate the transcriptional regulation of early responses of grapevine (Vitis vinifera) responding to ABA, different organs of grape (berries, shoot tips, leaves, roots and cell cultures) were treated with 10 μM (S)-(+)-ABA for 2 h. NimbleGen whole genome microarrays of Vitis vinifera were used to determine the effects of ABA on organ-specific mRNA expression patterns. Results: Transcriptomic analysis revealed 839 genes whose transcript abundances varied significantly in a specific organ in response to ABA treatment. No single gene exhibited the same changes in transcript abundance across all organs in response to ABA. The biochemical pathways affected by ABA were identified using the Cytoscape program with the BiNGO plug-in software. The results indicated that these 839 genes were involved in several biological processes such as flavonoid metabolism, response to reactive oxygen species, response to light, and response to temperature stimulus. ABA affected ion and water transporters, particularly in the root. The protein amino acid phosphorylation process was significantly overrepresented in shoot tips and roots treated with ABA. ABA affected mRNA abundance of genes (CYP707As, UGTs, and PP2Cs) associated with ABA degradation, conjugation, and the ABA signaling pathway. ABA also significantly affected the expression of several transcription factors (e.g. AP2/ERF, MYC/MYB, and bZIP/AREB). The greatest number of significantly differentially expressed genes was observed in the roots followed by cell cultures, leaves, berries, and shoot tips, respectively. Each organ had a unique set of gene responses to ABA. Conclusions: This study examined the short-term effects of ABA on different organs of grapevine. The responses of each organ were unique indicating that ABA signaling varies with the organ. Understanding the ABA responses in an organ-specific manner is crucial to fully understand hormone action and plant responses to water deficit.
Project description:MicroRNA (miRNA) is a class of functional non-coding small RNA with 19-25 nucleotides in length. Amur grape (Vitis amurensis Rupr.) is an important wild fruit crop with the strongest cold resistance in the Vitis genus and is used as an excellent breeding parent for grapevine, and with growing interest in terms of wine production. To date, there is a relatively large number of grapevine miRNAs (vv-miRNAs) from cultivated grapevine varieties such as Vitis vinifera L. and hybrids of V. vinifera and V. labrusca, but there is no report on miRNAs from Vitis amurensis Rupr, a wild grapevine species. In this study, a small RNA library from Amur grapes was constructed and Solexa technology used to perform deep sequencing of the library followed by subsequent bioinformatics analysis to identify new miRNAs. In total, 126 conserved miRNA belonging to 27 miRNA families were identified, and 34 known but non-conserved miRNAs were also found. Significantly, 72 new potential Amur grapevine-specific miRNAs were discovered. The sequences of these new potential va-miRNAs were further validated through miR-RACE, accumulation of 18 new va-miRNAs in seven tissues of grapevines were also confirmed by real time RT-PCR (qRT-PCR) analysis, and expression levels of va-miRNAs in flowers and berries were basically consistent in identity to those from deep sequenced sRNAs libraries of independent corresponding tissues. We also describe the conservation and variation of va-miRNAs using miR-SNPs and miR-LDs during plant evolution based on comparison of orthologous sequences, and revealed the number and sites of miR-SNP of diverse miRNA families exhibited distinct divergence. Finally, 346 target genes for the new miRNAs were predicted and they include a number of Amur grapevine stress tolerance genes and many genes regulating anthocyanin systhesis and sugar metabolism. Deep sequencing of short RNAs from Amur grapes flowers and fruits identified 72 new potential miRNAs and 34 known but non-conserved miRNAs, indicating that specific miRNAs exist in Amur grapes. These results show that a number of regulatory miRNAs exist in Amur grapes and play an important role in Amur grape growth, development, and response to abiotic or biotic stress.
Project description:Changes in the gene expression during exposure to salinity stress were compared among nodal roots, S-type lateral roots, and L-type lateral roots.
Project description:Grapevine rootstock 1616C shoots were sterilized and cultured on Murashige & Skoog (MS) medium containing 2% sucrose (w/v). Plantlets were grown in a growth chamber with a 16-h light/8-h dark cycle for 10 weeks at 25 °C. Plantlets with 4–5 leaves were chosen for use in stress treatments. Experiments were conducted with treatment groups: The control (C, without any chemical treatment), TM (treated with 5 μg mL-1 tunicamycin (TM)) and salt (treated with 400 mM NaCl). Microarray analysis was performed and we investigated transcript profiles in leaves of the salt-tolerant grapevine rootstock 1616C under salt- and ER-stress at 6 and 24 hours
Project description:Background: Global climate change, in particular the entailed predicted temperature increase, will noticeably affect plants vegetative and reproductive development. High temperatures alter the composition of the grapevine fruit, one of the most important fruits produced worldwide. This is leading to variable yield and quality, already observed in many growing regions in recent years. However, physiological processes underlying temperature response and tolerance of the grapevine fruit have hardly been investigated. Currently, all studies on fleshy fruits investigating their abiotic stress response on a molecular level were conducted during the day but possible night-specific variations were overlooked. The present study explores the grapevine fruit transcriptomic response at different developmental stages upon heat stress at day and night. Methodology/Principal Results: Short heat stresses (2 h) were applied at day and night to vines bearing clusters sequentially ordered according to the developmental stages along their vertical axis. The recently proposed microvine model was grown in climatic chambers in order to circumvent common constraints and biases introduced in field experiments with perennial vines. Post-véraison berry heterogeneity inside clusters was evaded upon constituting homogenous batches following organic acid and sugar measurements on individual berries. A whole genome transcriptomic approach was subsequently conducted using NimbelGen® 090918 12X microarrays (30K). Results revealed important differences in heat stress responsive pathways according to day or night treatment, in particular regarding genes within phenylpropanoid metabolism. Precise distinction of post-véraison stages led to a stage-specific detection of anthocyanin-related transcripts repressed by heat. Important modifications in cell wall-related processes as well as indications for a heat-induced delay of ripening and sugar accumulation were observed at véraison and reversed in later stages. Conclusion: This first day - night study on heat stress adaption of the grapevine berry shows that the transcriptome of fleshy fruits is differentially affected by abiotic stress at night. The present results emphasize the necessity to include different developmental stages and especially different time points in transcriptomic studies. A total of 12 samples were analyzed representing three berry developmental stages (two after the onset of ripening, one during green growth). At each stage, heat stress was applied at day and night. Controls and treated berry samples were drawn in triplicates (two in duplicates) at day and at night on the microvine dwarf (Dwarf Rapid Cycling and Continous Flowering; DRCF) gibberellin-insensitive (GAI) mutant.