ORCID IDs: 0000-0003-2205-1346 (Z.S.); 0000-0001-8717-4422 (H.M.).Drought dramatically affects plant growth and crop yield, but previous studies primarily examined responses to drought during vegetative development. Here, to study responses to drought during reproductive development, we grew Arabidopsis thaliana plants with limited water, under conditions that allowed the plants to initiate and complete reproduction. Drought treatment from just after the onset of flowering to seed maturation caused an early arrest of floral development and sterility. After acclimation, plants showed reduced fertility that persisted throughout reproductive development. Floral defects included abnormal anther development, lower pollen viability, reduced filament elongation, ovule abortion, and failure of flowers to open. Drought also caused differential expression of 4153 genes, including flowering time genes FLOWERING LOCUS T, SUPPRESSOR OF OVEREXPRESSION OF CO1, and LEAFY, genes regulating anther and pistil development, and stress-related transcription factors. Mutant phenotypes of hypersensitivity to drought and fewer differentially expressed genes suggest that DEHYDRATION RESPONSE ELEMENT B1A may have an important function in drought response in flowers. A more severe filament elongation defect under drought in myb21 plants demonstrated that appropriate stamen development requires MYB DOMAIN PROTEIN 21 under drought conditions. Our study reveals a regulatory cascade in reproductive responses and acclimation under drought.

ABSTRACT:Polymorphisms in the cytochrome P450 2D6 (CYP2D6) gene are a major cause of pharmacokinetic variability in human. Although the poor metabolizer phenotype is known to be caused by two null alleles leading to absence of functional CYP2D6 protein, the large variability among individuals with functional alleles remains mostly unexplained. Thus, the goal of this study was to examine the intrinsic enzymatic differences that exist among the several active CYP2D6 allelic variants. The relative catalytic activities (enzyme kinetics) of three functionally active human CYP2D6 allelic variants, CYP2D6.1, CYP2D6.10, and CYP2D6.17, were systematically investigated for their ability to metabolize a structurally diverse set of clinically important CYP2D6-metabolized drugs [atomoxetine, bufuralol, codeine, debrisoquine, dextromethorphan, (S)-fluoxetine, nortriptyline, and tramadol] and the effects of various CYP2D6-inhibitors [cocaine, (S)-fluoxetine, (S)-norfluoxetine, imipramine, quinidine, and thioridazine] on these three variants. The most significant difference observed was a consistent but substrate-dependent decease in the catalytic efficiencies of cDNAexpressed CYP2D6.10 and CYP2D6.17 compared with CYP2D6.1, yielding 1.32 to 27.9 and 7.33 to 80.4% of the efficiency of CYP2D6.1, respectively. The most important finding from this study is that there are mixed effects on the functionally reduced allelic variants in enzyme-substrate affinity or enzyme-inhibitor affinity, which is lower, higher, or comparable to that for CYP2D6.1. Considering the rather high frequencies of CYP2D6*10 and CYP2D6*17 alleles for Asians and African Americans, respectively, these data provide further insight into ethnic differences in CYP2D6-mediated drug metabolism. However, as with all in vitro to in vivo extrapolations, caution should be applied to the clinical consequences.

Pretreatment with SA enhanced the antioxidant defense activities in Cd-stressed rice, thus alleviating Cd-induced oxidative damage and enhancing Cd tolerance. AbstractTime-dependent changes in enzymatic and non-enzymatic antioxidants, and lipid peroxidation were investigated in roots of rice (Oryza sativa) grown hydroponically with Cd, with or without pretreatment of salicylic acid (SA). Exposure to 50 mM Cd significantly decreased root growth, and activities of superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD), but increased the concentrations of H 2 O 2 , malondialdehyde (MDA), ascorbic acid (AsA), glutathione (GSH) and non-protein thiols (NPT). However, pretreatment with 10 mM SA enhanced the activities of antioxidant enzymes and the concentrations of non-enzymatic antioxidants, but lowered the concentrations of H 2 O 2 and MDA in the Cd-stressed rice compared with the Cd treatment alone. Pretreatment with SA alleviated the Cd-induced inhibition of root growth. The results showed that pretreatment with SA enhanced the antioxidant defense activities in Cd-stressed rice, thus alleviating Cd-induced oxidative damage and enhancing Cd tolerance. The possible mechanism of SA-induced H 2 O 2 signaling in mediating Cd tolerance was discussed.

In this paper, the autoaggregating, coaggregating, hydrophobicity, and adhering abilities of 22 Lactobacillus strains belonging to different species were assessed. No correlation existed between autoaggregation and adhesion of the strains belonging to different species, whereas a positive correlation existed between autoaggregation and adhesion of the strains belonging to the same species. After treating with guanidine HCl, the autoaggregating and adhering abilities of some Lactobacillus strains decreased, indicating that surface-bound proteins and other macromolecules played a role in the adhering and autoaggregating abilities. The strains Lactobacillus plantarum 20 and 66 had higher adhesion and coaggregation abilities and should be further studied for their probable probiotic properties. Aggregating, coaggregating, and adhering abilities of Lactobacillus strains could be used as the preliminary criteria for selecting strains having probiotic potential.

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APETALA2/Ethylene-Responsive Factor (AP2/ERF) gene family is plant specific transcription factor. It plays critical roles in development process, tolerance to biotic and abiotic stresses, and responses to plant hormones. However, limited data are available on the contributions of AP2/ERF gene family in barley (Hordeum vulgare L.). In the present study, 121 HvAP2/ERF genes in barley were identified by using bioinformatics methods. A total of 118 HvAP2/ERF (97.5%) genes were located on seven chromosomes. According to phylogenetic classification of AP2/ERF family in Arabidopsis, HvAP2/ERF proteins were divided into AP2 (APETALA2), RAV (Related to ABI3/VP), DREB (dehydration responsive element binding), ERF (ethylene responsive factors) and soloist sub families. The analysis of duplication events indicated that tandem repeat and segmental duplication contributed to the expansion of the AP2/ERF family in barley. HvDREB1s/2s genes displayed various expression patterns under abiotic stress and phytohormone. Taken together, the data generated in this study will be useful for genome-wide analysis to determine the precise role of the HvAP2/ERF gene during barley development, abiotic stress and phytohormone responses with the ultimate goal of improving crop production.

Waterlogging is one of the major abiotic stresses that affects barley production and yield quality. Proteomics techniques have been widely utilized to explore the mechanisms involved in the responses to abiotic stress. In this study, two barley genotypes with contrasting responses to waterlogging stress were analyzed with proteomic technology. The waterlogging treatment caused a greater reduction in biomass and photosynthetic performance in the waterlogging-sensitive genotype TF57 than that in the waterlogging-tolerant genotype TF58. Under waterlogging stress, 30, 30, 20 and 20 differentially expressed proteins were identified through tandem mass spectrometry analysis in the leaves, adventitious roots, nodal roots and seminal roots, respectively. Among these proteins, photosynthesis-, metabolism- and energy-related proteins were differentially expressed in the leaves, with oxygen-evolving enhancer protein 1, ATP synthase subunit and heat shock protein 70 being up-regulated in TF58. Pyruvate decarboxylase (PDC), 1-amino cyclopropane 1-carboxylic acid oxidase (ACO), glutamine synthetase (GS), glutathione S-transferases (GST) and beta-1, 3-glucanase in adventitious, nodal and seminal roots were more abundant in TF58 than those in TF57 under waterlogging stress. Ten representative genes were selected for validation by qRT-PCR in different genotypes with known waterlogging tolerance, and the expression levels of three candidate genes (PDC, ACO and GST) increased in the roots of all genotypes in response to the waterlogging stress. These three genes might play a significant role in the adaptation process of barley under waterlogging stress. The current results partially determined the mechanisms of waterlogging tolerance and provided valuable information for the breeding of barley with enhanced tolerance to waterlogging.

dAlthough fructooligosaccharides (FOS) can selectively stimulate the growth and activity of probiotics and beneficially modulate the balance of intestinal microbiota, knowledge of the molecular mechanism for FOS metabolism by probiotics is still limited. Here a combined transcriptomic and physiological approach was used to survey the global alterations that occurred during the logarithmic growth of Lactobacillus plantarum ST-III using FOS or glucose as the sole carbon source. A total of 363 genes were differentially transcribed; in particular, two gene clusters were induced by FOS. Gene inactivation revealed that both of the clusters participated in the metabolism of FOS, which were transported across the membrane by two phosphotransferase systems (PTSs) and were subsequently hydrolyzed by a ␤-fructofuranosidase (SacA) in the cytoplasm. Combining the measurements of the transcriptome-and membrane-related features, we discovered that the genes involved in the biosynthesis of fatty acids (FAs) were repressed in cells grown on FOS; as a result, the FA profiles were altered by shortening of the carbon chains, after which membrane fluidity increased in response to FOS transport and utilization. Furthermore, incremental production of acetate was observed in both the transcriptomic and the metabolic experiments. Our results provided new insights into gene transcription, the production of metabolites, and membrane alterations that could explain FOS metabolism in L. plantarum. Prebiotics are defined as nondigestible food ingredients that selectively stimulate the growth and activity of beneficial microbial strains residing in the host gastrointestinal tract (GIT) (1). Among the sugars that are qualified as prebiotics, fructooligosaccharides (FOS) are fructose polymers of diverse lengths that can be either derivatives of simple fructose polymers or fructose moieties attached to a sucrose molecule (2). Because of the linkage configuration, FOS are not digested in the upper GIT and have been shown in vivo to beneficially modulate the composition of the intestinal microbiota by preferentially increasing the numbers of bifidobacteria and lactobacilli (3, 4).Despite considerable commercial and research interest in the beneficial effects of FOS, the molecular basis of FOS metabolism by specific members of the intestinal microbiota has only recently been examined. In order to understand the influence of environmental conditions on genome-wide gene expression levels, wholegenome DNA microarrays have often been used to survey the gene expression patterns of strains in the presence and absence of oligosaccharides (2, 5-8). On the basis of in silico analysis of the Lactobacillus acidophilus NCFM genome sequence, Barrangou et al. (2) identified a multiple-sugar metabolism (msm) operon that was involved in the metabolism of FOS. The msm operon encodes an ATP-dependent binding cassette-type transport system and a cytoplasmic ␤-fructosidase, which mediates FOS uptake and intracellular hydrolysis. Moreover, expression of the operon was i...