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Target and distractor templates play a pivotal role in guiding attentional control during visual search, with the former template facilitating target search and the latter template leading distractor suppression. We first investigated whether task-irrelevant colors could earn their value through color-target contingency in the training phase and bias attention when they became a distractor in search for a singleton shape during the test phase. Colors provided useful information for target selection, with high- and low-informational values, respectively, in Experiments 1 and 2. Experience-based attentional biases were observed in the first half of the former experiment, and null results were observed in the latter. Experiment 3 verified whether the null results were elicited because the response-relevant feature inside of the singleton shape was also a singleton. Colors were task defined in the training phase, and the test display was the same as that used in Experiment 2. Experience-based attentional biases were observed in the first half of the test phase. In Experiment 4, we tested whether decreasing the consistency of distractor processing can lengthen the duration of experience-based attentional biases by increasing the number of possible response-relevant features inside of the colored distractor. The results showed experience-based attentional biases throughout the test phase. The results highlight the ideas that the informational value provided by a feature dimension for facilitating target selection can modify a target template and that the consistency of rejecting a distractor feature can play a role in the formation of a distractor template., (© 2024. The Psychonomic Society, Inc.)

Repeating a single-prime stimulus as a target to respond to usually facilitates responses. However, sometimes, prime repetition slows the responses and produces the single-prime negative priming effect. In this study, the distractor set hypothesis was proposed as a mechanism of attentional control that can contribute toward single-prime negative priming. In Experiments 1a-1d, an integrated Stroop task was used. The results showed that the prime produced negative priming only when it matched the form of the competing distractors. A separate Stroop task was used in Experiments 2 and 3 and a flanker task was used in Experiments 4a and 4b. In both tasks, the results suggested that a prime produced negative priming when the location of the prime matched that of the distractors. In Experiment 5, alternative explanations including the effects of the prime-to-distractor similarity and the target set were examined. The results revealed that the distractor set, rather than the target set and the similarity between the prime and distractor, could better account for the negative priming effect. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

The global aging population is expanding at an increasingly rapid pace, with approximately one-fourth of the world's population expected to be composed of elderly individuals by 2050. Aging skin is one of the major characteristics expressed in the elderly. The study comprehensively utilizes both cell and animal experiments to confirm the skin anti-aging effects of Poria cocos ( P. cocos) , which is one of the most important traditional Chinese medicines classified as tonic Chinese medicine, commonly used to treat physical weakness and aging-associated diseases. We demonstrate in this study that P. cocos lanostane triterpenoids extract (Lipucan ® ) ameliorates aging skin and promotes collagen accumulation and hyaluronic acid production in galactose-induced aging rats. Purified lanostane triterpenoids were initially identified as active components in P. cocos , which significantly increased collagen and hyaluronic acid levels in cultured human skin cells.

Binding of target's location and response has been demonstrated in inhibition of return (IOR). This study further investigated the effects of task demand on the binding of the target's form to the target's location and response in the target-target paradigm of IOR. Experiments 1 (detection task) and 2 (localization task), in which the target's form was task irrelevant, suggested the binding of location and response. Experiment 3 (discrimination task), in which the target's form was task relevant, showed the binding of target's form, location, and response. These findings support the concept that the features and responses associated with a target are integrated into episodic representations or event files for the target event. Furthermore, task demand modulates the binding or retrieval of the event files., Competing Interests: The authors have no competing interests to declare., (Copyright: © 2022 The Author(s).)

Negative priming refers to the delayed response to a probe target that was previously a prime distractor. Memory retrieval has been proposed as one critical mechanism for the manifestation of negative priming. This perspective perpetuates that the contextual similarity between prime and probe trials should modulate memory retrieval, and therefore, affect negative priming. However, evidence for the contextual similarity effect in negative priming is mixed. The present study tested the hypothesis that attended contextual cues are more likely to be encoded into a distractor representation, and thus, are more likely to modulate the negative priming effect. By manipulating whether the contextual cues were relevant to the task demand in Section 1, and by manipulating whether cues had an abrupt or simultaneous onset, and by analysing reaction time (RT) distributions of the data in Section 2, our results demonstrated that attended cues produced the contextual similarity effect in negative priming, especially when RTs were long.

In the present study, we investigated the binding of location and response in a detection task of the target-target paradigm of inhibition of return (IOR). Results showed a cost of responding to a target at the repeated location (IOR) when the response was not repeated and an effect of facilitation of return (FOR) when the response was repeated. These findings suggest that when responding to a target, its location and the response to it are integrated together. In addition, an analysis of the Vincentized cumulative response time (RT) distribution further showed that memory retrieval of event representations requires time to operate. These findings were discussed according to the theoretical framework of event files.

Inhibition of return (IOR) refers to slower responses to a target presented at a previously cued vs. uncued location. The present study investigated the role of memory retrieval in IOR by manipulating the contextual similarity between two successive targets in the target-target IOR paradigm. Successive targets were presented in either the same color (same-context condition) or different colors (different-context condition). Results of two experiments showed that IOR was greater in the same-context than the different-context condition. In addition, Experiment 2 showed that this context effect occurs with long response times (RTs), suggesting that memory retrieval, which requires time to manifest, plays an important role in IOR., (Copyright © 2020 Chao, Kuo, Chen and Hsiao.)

Cistanche tubulosa aqueous extract (CTE) is already used as a botanical prescription drug for treating dementia in China. Our previous studies reported that phenylethanoid glycosides of CTE have anti-Alzheimer's disease (AD) activity by inhibiting amyloid β peptide (Aβ) aggregation and deposition. However, recent studies considered that the phenylethanoid glycosides may be metabolized by intestinal bacteria, because all analysis results showed that the bioavailability of phenylethanoid glycosides is extremely low. In this study we demonstrate how iron chelation plays a crucial role in the Aβ aggregation and deposition inhibition mechanism of phenylethanoid glycosides of CTE. In addition, we further proved phenylethanoid glycosides ( 1 ⁻ 3 ) could reach brain. Active CTE component and action mechanism confirmation will be a great help for product quality control and bioavailability studies in the future. At the same time, we provide a new analysis method useful in determining phenylethanoid glycosides ( 1 ⁻ 3 ) in plants, foods, blood, and tissues for chemical fingerprint and pharmacokinetic research.

The present study examines how a person's working memory capacity (WMC) and awareness of change in context influences modulating inhibitory control. Context was manipulated by changing the predictive validity of a prime to a following target (i.e., the proportion of prime repetition) across three phases in a single-prime negative priming task. The prime was a distractor for the following target when the proportion was 25% (in the first and third phases) and a useful cue when the proportion rose to 75% (in the second phase). Participants' WMCs were measured and whether they were aware of the change of the prime-repetition proportion was determined in interviews at the end of the experiment. We found that when the stimulus-onset asynchrony (SOA) was short (Experiment 1), participants aware of the change of prime-repetition proportion showed a null negative priming effect when the contingency increased from 25% to 75%, and then rebooted the effect when it decreased back to 25%, thus indicating an ability to modulate inhibitory control as context varied. In contrast, the unaware participants kept inhibiting primes all the time. When SOA was long (Experiment 2), participants with awareness even showed a positive priming effect when the prime-repetition proportion increased. Surprisingly, participants' WMCs did not matter except for the conscious strategy used in the long-SOA condition. This is the first study simultaneously investigating how WMC and awareness can affect people's ability to modulate inhibitory control and reveals that awareness plays a more direct role in such modulation than does WMC., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Single-prime negative priming refers to a phenomenon whereby repeating a single prime as a probe target slows responses to that target. This phenomenon is modulated by cognitive control when the contingency between the prime and probe target is higher than chance. The present study investigated the role of prime awareness and awareness of the contingency within the control mechanism during single-prime negative priming. Results showed that while single-prime negative priming occurred regardless of participant awareness, the control mechanism was modulated by prime awareness and perceived contingency., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Background: Hydrogen cyanamide (HC) and pruning (P) have frequently been used to break dormancy in grapevine floral buds. However, the exact underlying mechanism remains elusive. This study aimed to address the early mode of action of these treatments on accumulation of reactive oxygen species (ROS) and reactive nitrogen species (RNS) and expression of related genes in the dormancy breaking buds of grapevine in the summer., Results: The budbreak rates induced by pruning (P), hydrogen cyanamide (HC), pruning plus hydrogen cyanamide (PHC) and water (control) after 8 days were 33, 53, 95, and 0 %, respectively. Clearly, HC was more effective in stimulating grapevine budbreak and P further enhanced its potency. In situ staining of longitudinal bud sections after 12 h of treatments detected high levels of ROS and nitric oxide (NO) accumulated in the buds treated with PHC, compared with HC or P alone. The amounts of ROS and NO accumulated were highly correlated with the rates of budbreak among these treatments, highlighting the importance of a rapid, transient accumulation of sublethal levels of ROS and RNS in dormancy breaking. Microarray analysis revealed specific alterations in gene expression in dormancy breaking buds induced by P, HC and PHC after 24 h of treatment. Relative to control, PHC altered the expression of the largest number of genes, while P affected the expression of the least number of genes. PHC also exerted a greater intensity in transcriptional activation of these genes. Gene ontology (GO) analysis suggests that alteration in expression of ROS related genes is the major factor responsible for budbreak. qRT-PCR analysis revealed the transient expression dynamics of 12 specific genes related to ROS generation and scavenge during the 48 h treatment with PHC., Conclusion: Our results suggest that rapid accumulation of ROS and NO at early stage is important for dormancy release in grapevine in the summer, and the identification of the commonly expressed specific genes among the treatments allowed the construction of the signal transduction pathway related to ROS/RNS metabolism during dormancy release. The rapid accumulation of a sublethal level of ROS/RNS subsequently induces cell wall loosening and expansion for bud sprouting.

Recent studies have demonstrated that the contents of working memory capture attention when performing a visual search task. However, it remains an intriguing and unresolved question whether all kinds of items stored in working memory capture attention. The present study investigated this issue by manipulating the attentional tags (target or distractor) associated with information maintained in working memory. The results showed that working memory-driven attentional capture is a flexible process, and that attentional tags associated with items stored in working memory do modulate attentional capture. When items were tagged as a target, they automatically captured attention; however, when items were tagged as a distractor, attentional capture was reduced.

The root of Coptis chinensis Franch. (COCH) is regularly used for medicinal purposes, and has been prescribed alone or in combination with other traditional herbs for the treatment of diabetes. To investigate the effects of COCH on glucose utilization by skeletal muscles, we prepared an ethanol extract of COCH root (COCH-Et) partitioned with dichloromethane, n-butanol, and water and tested its effects on glucose uptake in differentiated C2C12 myotubes. We found that dichloromethane and n-butanol sub-fractions of COCH-Et promoted glucose uptake in differentiated C2C12 cells at 50 μg/mL. Further fractionation of these preparations by using column chromatography, analysis of their effects on glucose uptake and characterization using nuclear magnetic resonance, mass spectrometry, and thin layer chromatography helped identify two new alkaloids, 8,13-dioxocoptisine hydroxide (1) and coptisonine (2), together with eleven known compounds. These were isolated from the dichloromethane layer of COCH-Et. In particular, exposure of C2C12 cells to berberine (6) at 12.5 and 6.25 μg/mL for 24h resulted in significant promotion of glucose uptake. Coptisonine (2) and octadecyl caffeate (9) also stimulated glucose uptake at 25 and 50 μg/mL. These findings indicate that active constituents of COCH root may help alleviate hyperglycemia in diabetes by promoting glucose uptake by skeletal muscles., (Copyright © 2014. Published by Elsevier B.V.)

Single-prime negative priming refers to the phenomenon in which after a single prime word is briefly presented, repeating it as the probe target results in a delay in responding to the target. The present study investigated the locus of this negative priming effect. Experiment 1 showed that repeating the identity of the prime produced a negative priming effect but merely repeating the response of the prime did not. Experiment 2 showed that the negative priming effect transformed into positive priming when the probe distractor was absent. Experiments 3 and 4 further revealed that single-prime negative priming was observed when the perceptual form was repeated. Taken together, these results suggest that single-prime negative priming involves a perceptual locus., (Copyright © 2013 Elsevier B.V. All rights reserved.)

The current study used a naming task to investigate whether strategic control could modulate the process of attentional capture that is driven by working memory. The use of a naming task to engage working memory eliminates potential strategic perceptual resampling, which may have played a role in several previous studies. After naming a prime, participants performed a selection task in which they judged the direction of a moving target in each trial. Prime validity, which is the probability that the primes are identical to the selection targets, was manipulated across four experiments. The results showed that reaction times to the motion judgment were faster in the valid condition than in the invalid condition when the prime validity was 50% (Experiment 1A). These results occurred even in the presence of a highly informative spatial cue that predicted the target's location (Experiment 4). A larger capturing effect was observed when the validity was 70% (Experiments 2 and 3). When the prime validity was lower than the chance level (0% in Experiment 1B; 15% in Experiments 2 and 3), a validity effect was not observed. Thus, the results suggest that there is a strong tendency for working memory to capture attention by default when there is no reason to avoid the influence of primes. When there is a reason to avoid the influence, strategic control modulates the attentional capture that is driven by working memory.

In a location-selection task, the repetition of a prior distractor location as the target location would slow down the response. This effect is termed the location negative priming (NP) effect. Recently, it has been demonstrated that repetition of a prior target location as the current target location would also slow down response. Because such target-to-target repetition cost is similar to the phenomenon of inhibition of return (IOR), the possibility of a common mechanism underlying target-to-target repetition cost, location NP, and IOR has been proposed. The current study evaluated this hypothesis by combining a spatial-cuing task with a location NP task. The results of three experiments demonstrated that although IOR interacted with target-to-target repetition cost, there was no interaction between IOR and location NP. These findings suggest that target-to-target repetition cost is more likely to share a common mechanism with IOR, and target-to-target repetition cost and location NP should be attributed to different processes.

The current study investigated attentional control through active inhibition of the identity of the distractor. Adapting a Stroop paradigm, the distractor word was presented in advance and made to disappear, followed by the presentation of a Stroop stimulus. Participants were instructed to inhibit the distractor in order to reduce its interference. Experiments 1 and 2 demonstrated that the distractor precue facilitated Stroop color naming by reducing Stroop interference. Experiment 3 demonstrated beneficial effects of the distractor precue when congruent trials were introduced. Experiment 4 showed that the distractor precue benefit was observed when the cue and target were in different forms. Experiment 5 indicated that if the item used as the cue became the target, naming it took longer in order to overcome the inhibitory effect. Experiment 6 demonstrated that the benefit of the distractor precue was not observed when the cue was uninformative. Finally, Experiment 7 demonstrated that active inhibition required working-memory resources to operate. This study suggests that the best explanation for the distractor precue benefit is the active inhibition account.

Negative priming refers to the phenomenon of a slowed response time to a previously ignored distractor. Identity negative priming can be observed when the identity of a previous distractor is repeated as the target identity, and location negative priming can be observed when the spatial location of a previous distractor is repeated as the target location. This article reviewed and integrated previous findings and provided empirical evidence to show the dissociations between location and identity negative priming: (a) the removal of probe distractor impeded identity negative priming but not location negative priming; (b) identity negative priming was modulated by the distance between the target and distractor, while location negative priming was not; and (c) perceptual grouping of the target and distractor affected identity negative priming but not location negative priming., (Copyright © 2010 Elsevier B.V. All rights reserved.)

This study investigated the active inhibition of precued distractor locations. In this study, the distractor location was precued by an arrow. Experiment 1 indicated that a valid precue could facilitate target localization. Experiment 2 demonstrated that when conflict trials were included, the distractor precue benefit was eliminated. Experiment 3 further showed that active inhibition required time to operate. The distractor precue benefit was observed only when the stimulus onset asynchrony between the precue and the target and distractor display was long. Experiment 4 illustrated that the benefit was not contingent on precuing the distractor response. Experiment 5 indicated that the benefit of distractor precuing was not due to the activation of target locations, and Experiment 6 showed that this benefit was due to attentional inhibition. Finally, Experiment 7 demonstrated that active inhibition of spatial location required an attentional resource to operate. These results indicated how a top-down mechanism exerted control on distractor locations., (Copyright 2010 APA, all rights reserved.)

After the presentation of an uninformative spatial cue, it usually takes participants more time to respond to a target that appears at the cued location when the interval between the cue and target is long. This phenomenon is named inhibition of return (IOR), implying that returning attention to the cued location is inhibited because of attentional disengagement. The present study investigated whether irrelevant emotional information is processed by the attentional system in a similar manner. Uninformative positive and negative emotional cues were presented at the center of the screen, and faces were presented as the target. An emotional expression detection task was used to reveal the inhibitory and facilitatory aftereffects of the attentional processing of the emotional cues. An emotion-based IOR effect on reaction time was observed only after the presence of a negative emotional cue, implying that the attentional system tends to inhibit irrelevant negative emotion but not inhibit irrelevant positive emotion., (Copyright 2010 APA, all rights reserved.)

Single-prime negative priming refers to the phenomenon wherein repetition of a prime as the probe target results in delayed response. Sometimes this effect has been found to be contingent on participants' unawareness of the primes, and sometimes it has not. Further, sometimes this effect has been found to be eliminated when the prime could predict the following probe target, and sometimes it has not. An integrative account is postulated to account for these findings. Three experiments supported this account by demonstrating that (a) regardless of the proportion of prime repetition, negative priming was the default effect; (b) the control mechanism was triggered to activate the prime after there was enough practice for the detection of the contingency between the prime and probe; and (c) it took time for the control mechanism to overcome the negative-priming effect and produce a positive-priming effect., ((c) 2009 APA, all rights reserved.)

Background: Debaryomyces hansenii is one of the most salt tolerant species of yeast and has become a model organism for the study of tolerance mechanisms against salinity. The goal of this study was to identify key upregulated genes that are involved in its adaptation to high salinity., Results: By using forward subtractive hybridization we have cloned and sequenced DhAHP from D. hansenii that is significantly upregulated during salinity stress. DhAHP is orthologous to the alkly hydroperoxide reductase of the peroxiredoxin gene family, which catalyzes the reduction of peroxides at the expense of thiol compounds. The full-lengthed cDNA of DhAHP has 674 bp of nucleotide and contains a 516 bp open reading frame (ORF) encoding a deduced protein of 172 amino acid residues (18.3 kDa). D. hansenii Ahp is a cytosolic protein that belongs to the Ahp of the 1-Cys type peroxiredoxins. Phylogentically, the DhAhp and Candida albicans Ahp11 (Swiss-Prot: Q5AF44) share a common ancestry but show divergent evolution. Silence of its expression in D. hansenii by RNAi resulted in decreased tolerance to salt whereas overexpression of DhAHP in D. hansenii and the salt-sensitive yeasts Saccharomyces cereviasiae and Pichia methanolica conferred a higher tolerance with a reduced level of reactive oxygen species., Conclusion: In conclusion, for the first time our study has identified alkly hydroperoxide reductase as a key protein involved in the salt tolerance of the extremely halophilic D. hansenii. Apparently, this enzyme plays a multi-functional role in the yeast's adaptation to salinity; it serves as a peroxidase in scavenging reactive oxygen species, as a molecular chaperone in protecting essential proteins from denaturation, and as a redox sensor in regulating H2O2-mediated cell defense signaling.

Negative priming (NP) refers to the delayed response to a probe target that was previously a prime distractor. One peculiar problem in NP literature is the observation that the manifestation of identity NP is contingent on the presence and type of probe distractors. When the probe distractors were completely removed, positive priming, rather than NP, was usually observed. This study investigated whether location NP was affected by the same manipulations. The proportion of ignored repetition trials, attended repetition trials, and control trials was manipulated across Experiments 1-3. These three experiments showed reliable location NP effect when the probe distractor was consistently absent. Experiment 4 showed that the presence of probe distractors did not increase the magnitude of the location NP effect. Experiment 5 showed that the location NP effect observed was not contingent on perceptual mismatching. These findings suggest that the presence of probe distractors is not a necessary component for the manifestation of location NP. Theoretical implications were discussed.

Attention capture by an exogenous cue can result in slowed responses to a target, which appeared at that cued location later. This is the phenomenon of inhibition of return (IOR). In the current study, the effect of IOR on performance in a location selection task was studied. A target and a distractor were presented at the same time, and the participants were instructed to indicate the location of the target by manual response. The results showed that it took longer to respond to the target at the cued location. More importantly, it took a shorter time to respond to the target when the distractor was presented at the cued location. These findings support the idea that IOR can facilitate performance in a target selection task if the distractor location is cued.

Negative priming refers to delayed response to previous distractors, and can reflect the operation of attentional selection in prime trials. One important feature of negative priming is that it is modulated by the characteristics of probe trials. The current study manipulated competition from probe distractors and prime-probe similarity to examine the effects of attentional demand and memory retrieval in probe trials. The results demonstrated that the effects of attentional demand and memory retrieval on negative priming were dynamic. Distractor competition in probe trials affected negative priming in Experiment 1, and prime-probe similarity affected negative priming in Experiment 2. Moreover, negative priming in Experiment 3 was observed either when competition from probe distractors was strong or when identical spatial layouts were used in prime-probe couplets. Taken together, either competition from probe distractors or prime-probe similarity of spatial layouts was critical to the manifestation of negative priming at one time. Implications for distractor inhibition and memory retrieval in negative priming were discussed.

Negative priming refers to delayed responses to previously ignored distractors. Unlike conventional studies of negative priming in which the attentional selection of a target against its distractors is required in prime trials (prime-selection negative priming), in single-prime negative priming, a prime stimulus is presented briefly. To further investigate the nature of single-prime negative priming, its properties were examined. In Experiment 1, the proportion of repetition was varied. The effect of single-prime negative priming was reduced when the proportion of repetition was high. In addition, Experiment 2 showed that high memory load could hamper the single-prime negative priming effect. Overall, the current study indicates controlled processing in single-prime negative priming and similarities between single-prime negative priming and prime-selection negative priming.

Inhibition of return (IOR) refers to the fact that it takes longer for people to attend to recently examined locations than to novel locations. It has been argued that a single mechanism governs both IOR and negative priming (NP). If this is true, IOR and NP should share similar characteristics. Since NP depends on the use of repeated stimuli, in this study the dependence of IOR on repeated stimuli was explored. Experiments 1A-1D showed that, at longer cue-to-target-onset asynchrony (CTOA) intervals (613 and 906 msec), IOR could be observed only at repeatedly stimulated locations. However, IOR was observed when CTOA was short (253 msec) regardless of stimulus repetition. Experiments 2 and 3 replicated Experiments 1A-1D with a within-subjects design. The important role of memory representations in IOR is proposed.

Negative priming manifests when a previously ignored stimulus becomes a target. The contingency of identity negative priming on repeated stimuli has been demonstrated, implying a crucial role for distractor competition. In this study, a naming task was used to examine whether location negative priming also relies on the repetition of locations. In Experiment 1, location negative priming was observed only when a small set of repeated locations was used. Positive priming was found instead when a large set of nonrepeated locations was used. Experiment 2 demonstrated that target-to-distractor distance modulated location priming effects, with priming effects observed only for a far distance. Experiments 3 and 4 demonstrated that the effect of location negative priming increased as locations repeated. Like identity negative priming, location negative priming depends on location repetition.

In two experiments, we examined negative priming produced by distractors of low activation. A hybrid methodology was adopted to incorporate a study phase in which stimuli repetitively served as a target or a distractor, and a test phase in which the relationship in prime-probe couplets was manipulated. A critical manipulation was the presence or absence of novel stimuli in the test phase to alter the list context. The results showed that prime distractors of low activation produced negative priming when the test phase did not include novel items, which provided an optimal retrieval context. Prime distractors of high activation reliably led to negative priming when the list context contained novel items, but the effect varied when the list context did not include novel items. Theoretical implications are discussed.

Negative priming occurs when a response is slower to a target that was a previously ignored stimulus. According to a computational model of inhibition, negative priming results from relative activation between a target and a distractor in probe trials. Thus, the degree of competition in the probe trial should influence negative priming. The results from three experiments supported this hypothesis. Probe distractors grouped with a target by a rectangle produced a larger negative priming effect than did distractors isolated from the target. Moreover, neither prime-probe similarity nor perceptual interference could explain the grouping effect. The results suggest that perceptual mechanisms can influence negative priming via a race in the probe trial.

The full-length cDNA of tobacco mosaic virus faba bean isolate (TMV-B) was amplified with RT-PCR in which T7 promoter sequence was added in the 5' terminus of its upstream primer, so that full-length cDNA was put directly under the control of a T7 promoter. The cDNA was cloned into plasmid pT7Blue and linear DNA was got by digesting the recombinant with KpnI or KpnI and PstI. Using these linear DNA and full-length PCR product as templates, respectively, their in vitro transcripts were inoculated to Nicotiana tabacum and Chenopodium amaranticolor. All of the transcripts had infectivity and produced symptoms similar to that of wild TMV. It was found that transcripts of the full-length PCR product had higher infectious efficiency than those of linear DNA.