Characterization of Polyphenolic Metabolites in the Seeds of <i>Vitis</i> Germplasm

The composition and content of polyphenols in the seeds of 91 grape accessions from 17 <i>Vitis</i> species were characterized. Eleven compounds, including 2 gallic derivatives, 3 monomeric flavan-3-ols, 3 flavonols, resveratrol, and procyanidin B1 and B2, were identified via HPLC–MS and quantified by HPLC–DAD. In addition, seventeen dimeric and trimeric flavan-3-ols were also quantified. Tremendous variation was observed both among and within species for these compounds. Monomeric flavan-3-ols were the most abundant polyphenols in seeds, followed by dimeric and trimeric flavan-3-ols, which collectively accounted for more than 96% of the total polyphenols. <i>V. palmata</i>, <i>V. vinifera</i>, and <i>V. vulpina</i> had significantly higher content of total polyphenols than other species. A number of <i>Vitis</i> accessions with high content of various types of seed polyphenols were identified, and they can serve as potential germplasm for improving the composition and content of seed polyphenols in cultivated grapes

Isolation of a strong guard cell promoter and its potential as a research tool-4

Ng epidermal cells were not fluorescent. B. The 6 guard cells in panel A all produced intracellular calcium transients in response to imposed calcium oscillations. The arrows mark the switch point from the depolarizing buffer to the Ca-containing hyperpolarizing buffer (see Methods). C. A pseudo-colored ratiometric image of a leaf from an intact Col plants transformed with . The orange-yellow color indicates higher [Ca] and the blue color indicates lower [Ca]. Spontaneous calcium transients occurred in leaves of intact plants (movies are shown as additional files and ). D. A time course (25 minutes) of the emission ratios of the two guard cells marked by an arrow in C shows that spontaneous calcium transients occur in intact plants. The ratio was calculated for individual cells by dividing the YFP emission intensity by the CFP emission intensity.<p><b>Copyright information:</b></p><p>Taken from "Isolation of a strong guard cell promoter and its potential as a research tool"</p><p>http://www.plantmethods.com/content/4/1/6</p><p>Plant Methods 2008;4():6-6.</p><p>Published online 19 Feb 2008</p><p>PMCID:PMC2323621.</p><p></p

Isolation of a strong guard cell promoter and its potential as a research tool-0

, (At1g22690), and (At5g09810) from two independent microarrays are displayed. While , and all exhibited guard cell-specific expression, the transcript level of was the highest among the three genes. also exhibited very strong guard cell expression, but its expression level in mesophyll cells was strongly induced by ABA treatment.<p><b>Copyright information:</b></p><p>Taken from "Isolation of a strong guard cell promoter and its potential as a research tool"</p><p>http://www.plantmethods.com/content/4/1/6</p><p>Plant Methods 2008;4():6-6.</p><p>Published online 19 Feb 2008</p><p>PMCID:PMC2323621.</p><p></p

Isolation of a strong guard cell promoter and its potential as a research tool-2

Ited different levels of expression. C. Upper part of the hypocotyl. D. Young leaf and petiole. E. Leaf edge and petiole. F. & G. was mainly expressed in mature guard cells, very weak in young or immature guard cells (white arrows in (f) & (g)). H. & I.was expressed in guard cells on the hypocotyl. J. & K.was expressed in guard cells on the sepal. L. & M. mediated GUS (L) and GFP (M) reporter expression in clustered stomata in . N. mediated strong reporter gene expression in tobacco guard cells.<p><b>Copyright information:</b></p><p>Taken from "Isolation of a strong guard cell promoter and its potential as a research tool"</p><p>http://www.plantmethods.com/content/4/1/6</p><p>Plant Methods 2008;4():6-6.</p><p>Published online 19 Feb 2008</p><p>PMCID:PMC2323621.</p><p></p

Isolation of a strong guard cell promoter and its potential as a research tool-1

ATG) is located at +23/+25 bp. The Dof target sites, 5'-TAAAG-3' (+) or 5'-CTTTA-3'(-), which have been shown to contribute to guard-cell specific gene expression [24], are boxed. The ABRE, abscisic acid-response element, 5'-ACGTG-3' (+) or 5'-CACGT-3' (-), are underscored and labeled. The TATA box (5'-TATATAA-3') and the start codon (ATG) are shown in bold with dotted boxes. The arrowheads mark the positions for promoter deletion analyses in Figure 4.<p><b>Copyright information:</b></p><p>Taken from "Isolation of a strong guard cell promoter and its potential as a research tool"</p><p>http://www.plantmethods.com/content/4/1/6</p><p>Plant Methods 2008;4():6-6.</p><p>Published online 19 Feb 2008</p><p>PMCID:PMC2323621.</p><p></p

Isolation of a strong guard cell promoter and its potential as a research tool-6

, (At1g22690), and (At5g09810) from two independent microarrays are displayed. While , and all exhibited guard cell-specific expression, the transcript level of was the highest among the three genes. also exhibited very strong guard cell expression, but its expression level in mesophyll cells was strongly induced by ABA treatment.<p><b>Copyright information:</b></p><p>Taken from "Isolation of a strong guard cell promoter and its potential as a research tool"</p><p>http://www.plantmethods.com/content/4/1/6</p><p>Plant Methods 2008;4():6-6.</p><p>Published online 19 Feb 2008</p><p>PMCID:PMC2323621.</p><p></p

Isolation of a strong guard cell promoter and its potential as a research tool-8

Ited different levels of expression. C. Upper part of the hypocotyl. D. Young leaf and petiole. E. Leaf edge and petiole. F. & G. was mainly expressed in mature guard cells, very weak in young or immature guard cells (white arrows in (f) & (g)). H. & I.was expressed in guard cells on the hypocotyl. J. & K.was expressed in guard cells on the sepal. L. & M. mediated GUS (L) and GFP (M) reporter expression in clustered stomata in . N. mediated strong reporter gene expression in tobacco guard cells.<p><b>Copyright information:</b></p><p>Taken from "Isolation of a strong guard cell promoter and its potential as a research tool"</p><p>http://www.plantmethods.com/content/4/1/6</p><p>Plant Methods 2008;4():6-6.</p><p>Published online 19 Feb 2008</p><p>PMCID:PMC2323621.</p><p></p

Isolation of a strong guard cell promoter and its potential as a research tool-7

ATG) is located at +23/+25 bp. The Dof target sites, 5'-TAAAG-3' (+) or 5'-CTTTA-3'(-), which have been shown to contribute to guard-cell specific gene expression [24], are boxed. The ABRE, abscisic acid-response element, 5'-ACGTG-3' (+) or 5'-CACGT-3' (-), are underscored and labeled. The TATA box (5'-TATATAA-3') and the start codon (ATG) are shown in bold with dotted boxes. The arrowheads mark the positions for promoter deletion analyses in Figure 4.<p><b>Copyright information:</b></p><p>Taken from "Isolation of a strong guard cell promoter and its potential as a research tool"</p><p>http://www.plantmethods.com/content/4/1/6</p><p>Plant Methods 2008;4():6-6.</p><p>Published online 19 Feb 2008</p><p>PMCID:PMC2323621.</p><p></p

Molecular Characteristics and Efficacy of <i>16D10</i> siRNAs in Inhibiting Root-Knot Nematode Infection in Transgenic Grape Hairy Roots

<div><p>Root-knot nematodes (RKNs) infect many annual and perennial crops and are the most devastating soil-born pests in vineyards. To develop a biotech-based solution for controlling RKNs in grapes, we evaluated the efficacy of plant-derived RNA interference (RNAi) silencing of a conserved RKN effector gene, <i>16D10</i>, for nematode resistance in transgenic grape hairy roots. Two hairpin-based silencing constructs, containing a stem sequence of 42 bp (<i>pART27-42</i>) or 271 bp (<i>pART27-271</i>) of the <i>16D10</i> gene, were transformed into grape hairy roots and compared for their small interfering RNA (siRNA) production and efficacy on suppression of nematode infection. Transgenic hairy root lines carrying either of the two RNAi constructs showed less susceptibility to nematode infection compared with control. Small RNA libraries from four <i>pART27-42</i> and two <i>pART27-271</i> hairy root lines were sequenced using an Illumina sequencing technology. The <i>pART27-42</i> lines produced hundred times more <i>16D10</i>-specific siRNAs than the <i>pART27-271</i> lines. On average the <i>16D10</i> siRNA population had higher GC content than the <i>16D10</i> stem sequences in the RNAi constructs, supporting previous observation that plant dicer-like enzymes prefer GC-rich sequences as substrates for siRNA production. The stems of the <i>16D10</i> RNAi constructs were not equally processed into siRNAs. Several hot spots for siRNA production were found in similar positions of the hairpin stems in <i>pART27-42</i> and <i>pART27-271</i>. Interestingly, stem sequences at the loop terminus produced more siRNAs than those at the stem base. Furthermore, the relative abundance of guide and passenger single-stranded RNAs from putative siRNA duplexes was largely correlated with their 5′ end thermodynamic strength. This study demonstrated the feasibility of using a plant-derived RNAi approach for generation of novel nematode resistance in grapes and revealed several interesting molecular characteristics of transgene siRNAs important for optimizing plant RNAi constructs.</p></div

Isolation of a strong guard cell promoter and its potential as a research tool-3

(-1140/+23) promoter mediated stronger GUS expression in guard cells than the original full-length promoter (FL) (-1693/+23). GUS expression of and was weaker than that of the and . The shortest promoter (D4) (-224/+23) drives reporter expression in tissues and cells besides guard cells. B. Serial deletion of the promoter defines regions for guard cell expression. The black arrowheads stand for TAAAG elements while the smaller gray arrowheads stand for AAAAG elements. Arrowheads on the top of the promoter line are on the sense strand while arrowheads below the promoter line are on the antisense strand. The central TAAAG on the sense strand was also marked by a star and was chosen for block mutagenesis. The region from -1693 to -1140 contains repressor elements for guard cell expression and the region from -1140 to -224 contains elements for guard cell specificity and also enhancer elements for guard cells expression.<p><b>Copyright information:</b></p><p>Taken from "Isolation of a strong guard cell promoter and its potential as a research tool"</p><p>http://www.plantmethods.com/content/4/1/6</p><p>Plant Methods 2008;4():6-6.</p><p>Published online 19 Feb 2008</p><p>PMCID:PMC2323621.</p><p></p