Summary RING (really interesting new gene) zinc-finger proteins have important regulatory roles in the development of a variety of organisms. The XERICO gene encodes a small protein (162 amino acids) with an N-terminal transmembrane domain and a RING-H2 zinc-finger motif located at the C-terminus. In silico gene-expression analysis indicated that XERICO is induced by salt and osmotic stress. Compared with wild-type (WT) Arabidopsis plants, transgenic plants overexpressing XERICO (35S::XERICO) exhibited hypersensitivity to salt and osmotic stress and exogenous abscisic acid (ABA) during germination and early seedling growth. When subjected to a drought treatment, transcriptional upregulation of a key ABA-biosynthesis gene, AtNCED3, was much faster and stronger in 35S::XERICO plants compared with WT plants. Further, upregulation of XERICO substantially increased cellular ABA levels. The adult 35S::XERICO plants, in contrast to early seedling growth, showed a marked increase in their tolerance to drought stress. Yeast two-hybrid screening indicated that XERICO interacts with an E2 ubiquitin-conjugating enzyme (AtUBC8) and ASK1-interacting F-box protein (AtTLP9), which is involved in the ABA-signaling pathway. Affymetrix GeneChip array analysis showed that the expressions of many of the genes involved in the biosynthesis of plant hormones (e.g. ethylene, brassinosteroid, gibberellic acid) were significantly changed in the 35S::XERICO plants. These results suggest that the homeostasis of various plant hormones might be altered in 35S::XERICO plants, possibly by overaccumulation of ABA.

Mycobacterium tuberculosis is the cause of one of the most deadly diseases of mankind, and despite the availability of effective treatments, tuberculosis (TB) remains a major public health threat. The difficult challenges in treating multiple-drugresistant (MDR) and extensively drug-resistant (XDR) TB and the importance of shortening the duration of treatment to improve patients' compliance make the discovery of new anti-TB drugs imperative (1-5). Attempts to discover new TB drugs and targets via large-scale screening against intact mycobacteria have largely been confined to synthetic compound libraries and to date have yielded only one new clinical TB drug, the diarylquinoline bedaquiline (6, 7). Although very potent, to be of maximum benefit, bedaquiline, a diarylquinoline, and nitroimidazoles (8) require new companion drugs to be used in a multidrug regimen.While the intensive search for antibiotics from soil microorganisms in the mid-20th century yielded several clinically useful TB drugs, the pathogenic nature of M. tuberculosis and its extremely slow growth rate did not allow classical agar diffusion tests and excluded M. tuberculosis from the initial target panel. The discovery of TB drugs of natural origin at that time therefore relied upon the detection of activity against nonmycobacteria in agar diffusion assays followed by bioassay-guided isolation of the active principle, again using nonmycobacteria. Activity against M. tuberculosis was only assessed once the active principle was purified.Because M. tuberculosis is uniquely susceptible to a number of antimicrobial agents, a high-throughput screening (HTS) of actinomycete extracts directly against the virulent H37Rv strain was conducted, and this campaign revealed selective anti-TB peptides produced by a genetically distinct Nonomuraea species, strain MJM5123. Here, we describe the activity profile of ecumicin, its efficacy in infected mice, the identification of its molecular target, and the elucidation of its unusual mechanism of action. MATERIALS AND METHODSHigh-throughput screening. Approximately 7,000 actinomycete cultures isolated from Korea, China, Nepal, the Philippines, Vietnam, Antarctica, and the Arctic Circle and maintained at Myongji University, South Korea, were fermented in 20-ml cultures in glucose-soybean starch (GSS) medium (rich medium), Bennett's medium (normal medium), and dextrinyeast-corn steep liquor (DYC) medium (minimal medium) (see Table S1 in the supplemental material). The mycelia and culture medium supernatants were separated and extracted with methanol and ethyl acetate, respectively. Nine extracts were thus generated from each microbial isolate.

Biological control and plant growth promotion by plant beneficial microbes has been viewed as an alternative to the use of chemical pesticides and fertilizers. Bacteria and fungi that are naturally associated with plants and have a beneficial effect on plant growth by the alleviation of biotic and abiotic stresses were isolated and developed into biocontrol (BCA) and plant growth-promoting agents (PGPA). Actinobacteria are a group of important plant-associated spore-forming bacteria, which have been studied for their biocontrol, plant growth promotion, and interaction with plants. This review summarizes the effects of actinobacteria as BCA, PGPA, and its beneficial associations with plants.

SummaryVascular plants evolved to have xylem that provides physical support for their growing body and serves as a conduit for water and nutrient transport. In a previous study, we used comparative-transcriptome analyses to select a group of genes that were upregulated in xylem of Arabidopsis plants undergoing secondary growth. Subsequent analyses identified a plant-specific NAC-domain transcription factor gene (ANAC012) as a candidate for genetic regulation of xylem formation. Promoter-GUS analyses showed that ANAC012 expression was preferentially localized in the (pro)cambium region of inflorescence stem and root. Using yeast transactivation analyses, we confirmed the function of ANAC012 as a transcriptional activator, and identified an activation domain in the C terminus. Ectopic overexpression of ANAC012 in Arabidopsis (35S::ANAC012 plants) dramatically suppressed secondary wall deposition in the xylary fiber and slightly increased cell-wall thickness in the xylem vessels. Cellulose compositions of the cell wall were decreased in the inflorescent stems and roots of 35S::ANAC012 plants, probably resulting from defects in xylary fiber formation. Our data suggest that ANAC012 may act as a negative regulator of secondary wall thickening in xylary fibers.

Humic substances (HSs) have considerable effects on soil fertility and crop productivity owing to their unique physiochemical and biochemical properties, and play a vital role in establishing biotic and abiotic interactions within the plant rhizosphere. A comprehensive understanding of the mode of action and tissue distribution of HS is, however, required, as this knowledge could be useful for devising advanced rhizospheric management practices. These substances trigger various molecular processes in plant cells, and can strengthen the plant’s tolerance to various kinds of abiotic stresses. HS manifest their effects in cells through genetic, post-transcriptional, and post-translational modifications of signaling entities that trigger different molecular, biochemical, and physiological processes. Understanding of such fundamental mechanisms will provide a better perspective for defining the cues and signaling crosstalk of HS that mediate various metabolic and hormonal networks operating in plant systems. Various regulatory activities and distribution strategies of HS have been discussed in this review.

GCBE has a potential anti-obesity effect with lowering body fat accumulation by regulating adipogenesis and lipid metabolism-related genes and proteins in WAT and liver.

Aims: To identify an actinobacterial strain that can promote growth and alleviate salinity stress in tomato plants. Methods and Results: Actinobacteria were isolated from agricultural soil and screened for ACC deaminase activity, production of indole acetic acid (IAA), solubilization of tricalcium phosphate and sodium chloride (NaCl) salinity tolerance. Among the several strains tested, one strain designated PGPA39 exhibited higher IAA production, and phosphate solubilization in addition to ACC deaminase activity, and tolerance to 1 mol l À1 NaCl. Strain PGPA39 was identified as a Streptomyces strain based on 16S rDNA sequence and designated Streptomyces sp. strain PGPA39. It promoted the growth of Arabidopsis seedlings in vitro as evidenced by a significant increase in plant biomass and number of lateral roots. Salinity stress-alleviating activity of PGPA39 was evaluated using 'Micro Tom' tomato plants with 180 mmol l À1 NaCl stress under gnotobiotic condition. A significant increase in plant biomass and chlorophyll content and a reduction in leaf proline content were observed in PGPA39-inoculated tomato plants under salt stress compared with control and salt-stressed noninoculated plants.Conclusions: Streptomyces sp. strain PGPA39 alleviated salt stress and promoted the growth of tomato plants.Significance and Impact of the Study: This study shows the potential of Streptomyces sp. strain PGPA39 in alleviating salinity stress in tomato plants and could be utilized for stress alleviation in crop plants under field conditions.

The increasing demand for fresh-like food products and the potential health hazards of chemically preserved and processed food products have led to the advent of alternative technologies for the preservation and maintenance of the freshness of the food products. One such preservation strategy is the usage of bacteriocins or bacteriocins producing starter cultures for the preservation of the intended food matrixes. Bacteriocins are ribosomally synthesized smaller polypeptide molecules that exert antagonistic activity against closely related and unrelated group of bacteria. This review is aimed at bringing to lime light the various class of bacteriocins mainly from gram positive bacteria. The desirable characteristics of the bacteriocins which earn them a place in food preservation technology, the success story of the same in various food systems, the various challenges and the strategies employed to put them to work efficiently in various food systems has been discussed in this review. From the industrial point of view various aspects like the improvement of the producer strains, downstream processing and purification of the bacteriocins and recent trends in engineered bacteriocins has also been briefly discussed in this review.