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Background: High salinity adversely affects crop production. Pyruvic acid is the precursor of abscisic acid (ABA) and other chemicals that are synthesized in chloroplast, some of which are involved in the response to salt. The transportation of pyruvic acid into chloroplast is mediated by pyruvate transporters. However, whether pyruvate transporters are involved in salt response has not been studied so far. Here, we answered this issue by assessing the function of a wheat pyruvate transporter in salt response. Results: A pyruvate transporter TaBASS2 was isolated from salt-tolerant wheat cultivar Shanrong 3. The expression of TaBASS2 was induced by NaCl stress as well as H2O2 and ABA treatments. Constitutive expression of TaBASS2 in Arabidopsis bass2-1 mutant complemented the mevastatin-sensitive phenotype that reflects the deficiency of transporting pyruvic acid into chloroplast. Overexpression of TaBASS2 enhanced salinity tolerance and reactive oxygen species scavenging in wheat. Arabidopsis constitutively expressing TaBASS2 also exhibited enhanced tolerance to salinity and oxidative stress. In Arabidopsis, TaBASS2 repressed the expression of ABA INSENSITIVE 4 (ABI4), a node linking ABA signaling and plastid retrograde signaling pathways. However, the enhanced salinity tolerance of TaBASS2 overexpression Arabidopsis was abolished when ABI4 expression was restored to the level of wild-type through overexpressing ABI4. Conclusions: Our work demonstrates that TaBASS2 enhances salinity tolerance of plants via modulating ABI4 expression. This indicates that pyruvate transporters indeed participate in the interaction of plants with environmental stimuli. [ABSTRACT FROM AUTHOR]

Background: Allopolyploid genome needs wide structural variation to deal with genomic shock. The introgression line, generated via asymmetric somatic hybridization, is introgressed with a minimum of exogenous chromatin, which also leads to genomic shock to induce genetic variation. However, the extent of its genomic variation and its difference from allopolyploidies remains unknown. Methods: Here, we explored this issue using the bread wheat cultivar SR3, a derivative of an asymmetric somatic hybrid between the cultivar JN177 and an accession of tall wheatgrass (Thinopyrum elongatum). The ESTs (expressed sequence taqs) were large-scale sequenced using the cDNA library constructed in each of SR3 and JN177. Point mutations and indels (insertions and deletions) of SR3 were calculated, and their difference from the genetic variation of bread wheat and its ancestors were compared, with aim to analyze the extent and pattern of sequence variation induced by somatic hybridization. Results: Both point mutations and indels (insertions and deletions) were frequently induced by somatic hybridization in the coding sequences. While the genomic shock caused by allopolyploidization tends to favor deletion over insertion, there was no evidence for such a preference following asymmetric somatic hybridization. The GC content of sequence adjacent to indel sites was also distinct from what has been observed in allopolyploids. Conclusions: This study demonstrates that asymmetric somatic hybridization induces high frequency of genetic variation in a manner partially different from allopolipoidization. Asymmetric somatic hybridization provides appropriate material to comprehensively explore the nature of the genetic variation induced by genomic shock. [ABSTRACT FROM AUTHOR]

Background: Personality disorders (PDs) during adolescence may, in addition to increasing risk for violent behaviors and suicide, also increase risk for elevated PD traits in adulthood. The aim of this study was to explore the prevalence of Cluster A and Cluster B PD traits and their relationships to demographic variables in Chinese high school students. Methods: A cohort of 3,552 students from eight high schools completed the Personality Diagnostic Questionnaire-4+ (PDQ-4+) and MacArthur Scale of Subjective Social Status-youth version (SSSy) questionnaires. Results: Boys scored higher than girls on the paranoid, schizotypal, antisocial, and narcissistic PDs. Freshmen and sophomores scored higher than juniors on schizoid, borderline, and antisocial PDs. Children in single-child families scored higher than nonsingletons on the paranoid and antisocial PDs. Students from single-parent households scored higher than students from double-parent households on the schizotypal and antisocial PDs, and students with remarried parents scored higher than students from double-parent households on the borderline and antisocial PDs. Students who had low perception of social status in the society ladder scored higher than those with a high perceived status on the schizoid and borderline PDs, but scored lower on the histrionic PD; students with a low subjective social status in the school community ladder scored higher scores than those with a high perceived status on the paranoid, schizoid, borderline, and antisocial PDs, but scored lower on the histrionic PD. Conclusions: Gender, grade, family structure, and subjective social status may affect the development of PDs. Longitudinal studies and studies of the full scope of PDs are needed to fully elucidate the impact of demographic variables on PD prevalence rates in adolescence and adulthood. [ABSTRACT FROM AUTHOR]

Background: Evidence has been assembled to suggest synonymous codon usage bias (SCUB) has close relationship with intron. However, the relationship (if any) between SCUB and intron number as well as exon position is at present rather unclear. Results: To explore this relationship, the sequences of a set of genes containing between zero and nine introns was extracted from the published genome sequences of three algal species, one moss, one fern and six angiosperms (three monocotyledonous species and three dicotyledonous species). In the algal genomes, the frequency of synonymous codons of the form NNG/NNC (codons with G and C at the third position) was positively related to intron number, but that of NNA/NNT was inversely correlated; the opposite was the case in the land plant genomes. The frequency of NNC/NNG was higher and that of NNA/NNT lower in two terminal exons than in the interstitial exons in the land plant genes, but the rule showed to be opposite in the algal genes. SCUB patterns in the interstitial and two terminal exons mirror the different evolutionary relationships between these plant species, while the first exon shows the highest level of conservation is therefore concluded to be the one which experiences the heaviest selection pressure. The phenomenon of SCUB may also be related to DNA methylation induced conversion of CG to AT. Conclusions: These data provide some evidence of linkage between SCUB, the evolution of introns and DNA methylation, which brings about a new perspective for understanding how genomic variation is created during plant evolution. [ABSTRACT FROM AUTHOR]