BackgroundGrapes are a major fruit crop around the world. Heat stress can significantly reduce grape yield and quality. Changes at the molecular level in response to heat stress and subsequent recovery are poorly understood. To elucidate the effect of heat stress and subsequent recovery on expression of genes by grape leaves representing the classic heat stress response and thermotolerance mechanisms, transcript abundance of grape (Vitis vinifera L.) leaves was quantified using the Affymetrix Grape Genome oligonucleotide microarray (15,700 transcripts), followed by quantitative Real-Time PCR validation for some transcript profiles.ResultsWe found that about 8% of the total probe sets were responsive to heat stress and/or to subsequent recovery in grape leaves. The heat stress and recovery responses were characterized by different transcriptional changes. The number of heat stress-regulated genes was almost twice the number of recovery-regulated genes. The responsive genes identified in this study belong to a large number of important traits and biological pathways, including cell rescue (i.e., antioxidant enzymes), protein fate (i.e., HSPs), primary and secondary metabolism, transcription factors, signal transduction, and development. We have identified some common genes and heat shock factors (HSFs) that were modulated differentially by heat stress and recovery. Most HSP genes were upregulated by heat stress but were downregulated by the recovery. On the other hand, some specific HSP genes or HSFs were uniquely responsive to heat stress or recovery.ConclusionThe effect of heat stress and recovery on grape appears to be associated with multiple processes and mechanisms including stress-related genes, transcription factors, and metabolism. Heat stress and recovery elicited common up- or downregulated genes as well as unique sets of responsive genes. Moreover, some genes were regulated in opposite directions by heat stress and recovery. The results indicated HSPs, especially small HSPs, antioxidant enzymes (i.e., ascorbate peroxidase), and galactinol synthase may be important to thermotolerance of grape. HSF30 may be a key regulator for heat stress and recovery, while HSF7 and HSF1 may only be specific to recovery. The identification of heat stress or recovery responsive genes in this study provides novel insights into the molecular basis for heat tolerance in grape leaves.

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[1] Current, luminosity, and electric field pulses in a rocket-triggered negative lightning flash have been analyzed based on the channel base current, high-speed video images, and electric field changes at 30 m from the channel. Among the 31 distinct current pulses, there are 4 return strokes, 18 typical M components, 5 large M components with unusual large peak current in a range of kiloamperes, 3 initial continuing current (ICC) pulses, and 1 stroke-M component (RM) event which exhibits both return stroke and M component features. The geometric mean of peak current is 13.5 kA, half peak width is 28.4 ms, and risetime from 10% to 90% peak is 1.1 ms for the 4 return strokes, while the corresponding values are 243 A, 400 ms, and 319 ms, respectively, for the 18 typical M components and 5.1 kA, 76.3 ms, and 34.6 ms, respectively, for the 5 large M components. The electric field and current waveforms of ICC pulses exhibit features similar to those of the M components, indicating the similarity of their mechanisms. Detectable optical luminosity is found just prior to all the pulse events, even return strokes. The M components are superimposed on a slowly varying continuing current, while the directly measured current prior to the return stroke is not significant. The simultaneous electric field and current waveform of RM implies a superposition of dart leader and M incident wave in the channel, and the possible reason is that two branches with common lower portions coexist simultaneously in the upper part of the discharge channel.

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The aim of this study was to evaluate the quality of life (QoL) in the older rural and urban Chinese populations in Zhejiang province. An analysis of the association between potential factors and QoL for these two groups was conducted. A cross-sectional study was conducted from October to December 2007. The total sample consisted of 2,441 rural and 2,554 urban participants. A Chinese version of the 36-item Short Form Health Survey (SF-36) was used to quantify the QoL of participants. A comparison between the QoL of rural and urban participants was made. The association between potential factors and QoL was performed using a multiple linear regression model. The study revealed all scale scores of SF-36 in the rural population were significantly lower than those in the urban population except general health (GH; p < .001). The common factors associated with high QoL in both older rural and urban populations were gender (male), tea consumption, income, and consumption of alcohol.