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TRIM28/KAP1/TIF1β is a crucial epigenetic modifier. Genetic ablation of trim28 is embryonic lethal, although RNAi-mediated knockdown in somatic cells yields viable cells. Reduction in TRIM28 abundance at the cellular or organismal level results in polyphenism. Posttranslational modifications such as phosphorylation and sumoylation have been shown to regulate TRIM28 activity. Moreover, several lysine residues of TRIM28 are subject to acetylation, but how acetylation of TRIM28 affects its functions remains poorly understood. Here, we report that, compared with wild-type TRIM28, the acetylation-mimic mutant TRIM28-K304Q has an altered interaction with Krüppel-associated box zinc-finger proteins (KRAB-ZNFs). The TRIM28-K304Q knock-in cells were created in K562 erythroleukemia cells by CRISPR-Cas9 (Clustered regularly interspaced short palindromic repeats/CRISPR-associated protein nuclease 9) gene editing method. Transcriptome analysis revealed that TRIM28-K304Q and TRIM28 knockout K562 cells had similar global gene expression profiles, yet the profiles differed considerably from wild-type K562 cells. The expression levels of embryonic-related globin gene and a platelet cell marker integrin-beta 3 were increased in TRIM28-K304Q mutant cells, indicating the induction of differentiation. In addition to the differentiation-related genes, many zinc-finger-proteins genes and imprinting genes were activated in TRIM28-K304Q cells; they were inhibited by wild-type TRIM28 via binding with KRAB-ZNFs. These results suggest that acetylation/deacetylation of K304 in TRIM28 constitutes a switch for regulating its interaction with KRAB-ZNFs and alters the gene regulation as demonstrated by the acetylation mimic TRIM28-K304Q.

The type VI secretion system (T6SS) is deployed by many proteobacteria to secrete effector proteins into bacterial competitors for competition or eukaryotic cells for pathogenesis. Agrobacteria, a group of soil-borne phytopathogens causing crown gall disease on various plant species, deploys the T6SS to attack closely- and distantly-related bacterial speciesin vitroandin planta. Current evidence suggests that the T6SS is not essential for pathogenesis under direct inoculation but it remains unknown whether the T6SS influences natural disease incidence or the microbial community within crown galls (i.e., gallobiome). To address these two key questions, we established a soil inoculation method on wounded tomato seedlings that mimics natural infections and developed a bacterial 16S rRNA gene amplicon enrichment sequencing platform. By comparing theAgrobacteriumwild-type strain C58 with two T6SS mutants, we demonstrate that the T6SS influences both disease occurrence and gallobiome composition. Based on multiple inoculation trials across seasons, all three strains could induce tumors but the mutants had significantly lower disease incidences. The season of inoculation played a more important role than the T6SS in shaping the gallobiome. The influence of T6SS was evident in summer, in which twoSphingomonasspecies and the family Burkhoderiaceae were enriched in the gallobiome induced by the mutants. Furtherin vitrocompetition and colonization assay demonstrated the T6SS-mediated antagonism to aSphingomonassp. R1 strain isolated from tomato rhizosphere in this study. In conclusion, this work demonstrates that theAgrobacteriumT6SS promotes tumorigenesis in infection process and provides competitive advantages in gall-associated microbiota.IMPORTANCEThe T6SS is widespread among Proteobacteria and used for interbacterial competition by agrobacteria, which are soil inhabitants and opportunistic bacterial pathogens causing crown gall disease in a wide range of plants. Current evidence indicates that the T6SS is not required for gall formation when agrobacteria are inoculated directly on plant wounding sites. However, in natural settings, agrobacteria may need to compete with other bacteria in bulk soil to gain access to plant wounds and influence microbial community inside crown galls. The role of the T6SS in these critical aspects of disease ecology have remained largely unknown. In this study, we successfully developed aSoilInoculation method coupled withBlocker-mediated enrichment ofBacterial 16S rRNA gene AmpliconSequencing, named as SI-BBacSeq, to address these two important questions. We provided evidence that the T6SS promotes disease occurrence and influences crown gall microbiota composition by interbacterial competition.

N-acetylglucosamine (GlcNAc) is the fundamental amino sugar moiety that is essential for protein glycosylation. UDP-GlcNAc, an active form of GlcNAc, is synthesized through the hexosamine biosynthetic pathway (HBP). Arabidopsis N-acetylglucosamine-1-P uridylyltransferases (GlcNAc1pUTs), encoded by

The bacterial genus Xylella contains plant pathogens that are major threats to agriculture in America and Europe. Although extensive research was conducted to characterize different subspecies of Xylella fastidiosa (Xf), comparative analysis at above-species levels was lacking due to the unavailability of appropriate data sets. Recently, a bacterium that causes pear leaf scorch (PLS) in Taiwan was described as the second Xylella species (i.e., Xylella taiwanensis; Xt). In this work, we report the complete genome sequence of Xt type strain PLS229T. The genome-scale phylogeny provided strong support that Xf subspecies pauca (Xfp) is the basal lineage of this species and Xylella was derived from the paraphyletic genus Xanthomonas. Quantification of genomic divergence indicated that different Xf subspecies share ∼87–95% of their chromosomal segments, while the two Xylella species share only ∼66–70%. Analysis of overall gene content suggested that Xt is most similar to Xf subspecies sandyi (Xfs). Based on the existing knowledge of Xf virulence genes, the homolog distribution among 28 Xylella representatives was examined. Among the 11 functional categories, those involved in secretion and metabolism are the most conserved ones with no copy number variation. In contrast, several genes related to adhesins, hydrolytic enzymes, and toxin-antitoxin systems are highly variable in their copy numbers. Those virulence genes with high levels of conservation or variation may be promising candidates for future studies. In summary, the new genome sequence and analysis reported in this work contributed to the study of several important pathogens in the family Xanthomonadaceae.

The bacterial genus Xylella contains plant pathogens that are major threats to agriculture in America and Europe. Although extensive research was conducted to characterize different subspecies of Xylella fastidiosa (Xf), comparative analysis at above-species levels were lacking due to the unavailability of appropriate data sets. Recently, a bacterium that causes pear leaf scorch (PLS) in Taiwan was described as the second Xylella species (i.e., Xylella taiwanensis; Xt). In this work, we report the complete genome sequence of Xt type strain PLS229T. The genome-scale phylogeny provided strong support that Xf subspecies pauca (Xfp) is the basal lineage of this species and Xylella was derived from the paraphyletic genus Xanthomonas. Quantification of genomic divergence indicated that different Xf subspecies share ∼87-95% of their chromosomal segments, while the two Xylella species share only ∼66-70%. Analysis of overall gene content suggested that Xt is most similar to Xf subspecies sandyi (Xfs). Based on the existing knowledge of Xf virulence genes, the homolog distribution among 28 Xylella representatives was examined. Among the 11 functional categories, those involved in secretion and metabolism are the most conserved ones with no copy number variation. In contrast, several genes related to adhesins, hydrolytic enzymes, and toxin-antitoxin systems are highly variable in their copy numbers. Those virulence genes with high levels of conservation or variation may be promising candidates for future studies. In summary, the new genome sequence and analysis reported in this work contributed to the study of several important pathogens in the family Xanthomonadaceae.Contribution to the FieldXylella fastidiosa is a plant-pathogenic bacterium with multiple subspecies that are major threats to agriculture in America and Europe. Although extensive research has been conducted, comparative analysis of this species with other bacteria is lacking due to the unavailability of known close relatives. In this work, we report the complete genome sequence of Xylella taiwanensis, a newly described species within the same genus. This new data set and our focused analysis helped to better understand the evolutionary relationships among different Xylella lineages and their genomic diversity. Moreover, detailed examination of their virulence genes identified those that are either highly conserved or variable, providing promising candidates for future studies to further investigate the molecular mechanisms of Xylella virulence.

BackgroundTRIM28/KAP1/TIF1β is a key epigenetic modifier. Genetic ablation of trim28 is embryonic lethal although RNAi-mediated knockdown in somatic cells yields viable cells. Reduction in TRIM28 abundance at the cellular or organismal level results in polyphenism. Posttranslational modifications such as phosphorylation and sumoylation have been shown to regulate TRIM28 activity. Moreover, the methylation of DNA, RNA and histones and acetylation of histones are key epigenetic modifications that regulate gene expression. A number of lysine residues of TRIM28 are subject to acetylation, but how acetylation of TRIM28 affects its functions remains poorly understood. ResultsHere we report that, compared with wild-type TRIM28, the acetylation-mimic mutant TRIM28-K304Q has an altered interaction with Krüppel-associated box zinc-finger proteins (KRAB-ZNFs), with consequent effects on the phenotype of the erythroleukemic cell line K562. TRIM28-K304Q was comparable with its wild-type counterpart with respect to intracellular level, homodimerization, phosphorylation at S473 and S824, and interactions with heterochromatin-binding protein HP1. The expression of embryonic-related and fetal globin genes was activated in TRIM28-K304Q mutant cells. Transcriptome analysis revealed that TRIM28-K304Q and TRIM28 knockout K562 cells had similar global gene expression profiles, yet the profiles differed considerably from that of wild-type K562 cells. The gene expression ensemble of mutant K562 cells indicated a general induction of differentiation-promoting genes and attenuation of proliferation-promoting genes. ConclusionsThese results suggest that acetylation/deacetylation of K304 in TRIM28 or TRIM28-K304Q constitutes a switch for regulating its interaction with KRAB-ZNFs and alters the gene regulation of this key epigenetic modifier as demonstrated by the acetylation mimic TRIM28-K304Q.

Summary Physiological trade-offs between mosquito immune response and reproductive capability can arise due to insufficient resource availability. C-type lectin family members may be involved in these processes. We established a GCTL-3−/− mutant Aedes aegypti using CRISPR/Cas9 to investigate the role of GCTL-3 in balancing the costs associated with immune responses to arboviral infection and reproduction. GCTL-3−/− mutants showed significantly reduced DENV-2 infection rate and gut commensal microbiota populations, as well as upregulated JAK/STAT, IMD, Toll, and AMPs immunological pathways. Mutants also had significantly shorter lifespans than controls and laid fewer eggs due to defective germ line development. dsRNA knock-down of Attacin and Gambicin, two targets of the AMPs pathway, partially rescued this reduction in reproductive capabilities. Upregulation of immune response following GCTL-3 knock-out therefore comes at a cost to reproductive fitness. Knock-out of other lectins may further improve our knowledge of the molecular and genetic mechanisms underlying reproduction-immunity trade-offs in mosquitoes., Graphical Abstract, Highlights • mosGCTL-3 mutants showed a reduced DENV-2 infection rate • mosGCTL-3 mutants had upregulated JAK/STAT, IMD, Toll, and AMPs pathway components • mosGCTL-3 knock-out led to reduced gut microbiota population sizes, and diversity • mosGCTL-3 regulates germ line development and influences fertility, Biological Sciences; Immunology; Microbiology Parasite

Agrobacterium tumefaciens is the causal agent of crown gall disease in a wide range of plants via a unique interkingdom DNA transfer from bacterial cells into the plant genome. Agrobacterium tumefaciens is capable of transferring its T-DNA into different plant parts at different developmental stages for transient and stable transformation. However, the plant genes and mechanisms involved in these transformation processes are not well understood. We used Arabidopsis thaliana Col-0 seedlings to reveal the gene expression profiles at early time points during Agrobacterium infection. Common and differentially expressed genes were found in shoots and roots. A gene ontology analysis showed that the glucosinolate (GS) biosynthesis pathway was an enriched common response. Strikingly, several genes involved in indole glucosinolate (iGS) modification and the camalexin biosynthesis pathway were up-regulated, whereas genes in aliphatic glucosinolate (aGS) biosynthesis were generally down-regulated, on Agrobacterium infection. Thus, we evaluated the impacts of GSs and camalexin during different stages of Agrobacterium-mediated transformation combining Arabidopsis mutant studies, metabolite profiling and exogenous applications of various GS hydrolysis products or camalexin. The results suggest that the iGS hydrolysis pathway plays an inhibitory role on transformation efficiency in Arabidopsis seedlings at the early infection stage. Later in the Agrobacterium infection process, the accumulation of camalexin is a key factor inhibiting tumour development on Arabidopsis inflorescence stalks. In conclusion, this study reveals the differential roles of GSs and camalexin at different stages of Agrobacterium-mediated transformation and provides new insights into crown gall disease control and improvement of plant transformation.

Agrobacterium tumefaciens is important in biotechnology due to its ability to transform eukaryotic cells. Although the molecular mechanisms have been studied extensively, previous studies were focused on the model strain C58. Consequently, nearly all of the commonly used strains for biotechnology application were derived from C58 and share similar host ranges. To overcome this limitation, better understanding of the natural genetic variation could provide valuable insights. In this study, we conducted comparative analysis between C58 and 1D1609. These two strains belong to different genomospecies within the species complex and have distinct infectivity profiles. Genome comparisons revealed that each strain has >1,000 unique genes in addition to the 4,115 shared genes. Furthermore, the divergence in gene content and sequences vary among replicons. The circular chromosome is much more conserved compared to the linear chromosome. To identify the genes that may contribute to their differentiation in virulence, we compared the transcriptomes to screen for genes differentially expressed in response to the inducer acetosyringone. Based on the RNA-Seq results with three biological replicates, ∼100 differentially expressed genes were identified in each strain. Intriguingly, homologous genes with the same expression pattern account for

The rice SUB1A-1 gene, which encodes a group VII ethylene response factor (ERFVII), plays a pivotal role in rice survival under flooding stress, as well as other abiotic stresses. In Arabidopsis , five ERFVII factors play roles in regulating hypoxic responses. A characteristic feature of Arabidopsis ERFVIIs is a destabilizing N terminus, which functions as an N-degron that targets them for degradation via the oxygen-dependent N-end rule pathway of proteolysis, but permits their stabilization during hypoxia for hypoxia-responsive signaling. Despite having the canonical N-degron sequence, SUB1A-1 is not under N-end rule regulation, suggesting a distinct hypoxia signaling pathway in rice during submergence. Herein we show that two other rice ERFVIIs gene, ERF66 and ERF67 , are directly transcriptionally up-regulated by SUB1A-1 under submergence. In contrast to SUB1A-1, ERF66 and ERF67 are substrates of the N-end rule pathway that are stabilized under hypoxia and may be responsible for triggering a stronger transcriptional response to promote submergence survival. In support of this, overexpression of ERF66 or ERF67 leads to activation of anaerobic survival genes and enhanced submergence tolerance. Furthermore, by using structural and protein-interaction analyses, we show that the C terminus of SUB1A-1 prevents its degradation via the N-end rule and directly interacts with the SUB1A-1 N terminus, which may explain the enhanced stability of SUB1A-1 despite bearing an N-degron sequence. In summary, our results suggest that SUB1A-1 , ERF66 , and ERF67 form a regulatory cascade involving transcriptional and N-end rule control, which allows rice to distinguish flooding from other SUB1A-1–regulated stresses.

In this study, different morphological ZnO nanostructures, those of sharp nanowires (NWs), rod NWs, and hexahedral-puncheon nanostructures, were grown in microfluidic channels on the same glass substrate. Characterizations of correspondent biomolecule binding properties were simulated and demonstrated. The surface was modified using 3-ammineopropyl-triethoxysilane (3-APTES) and biotin-N-hydroxysuccinimide ester (NHS-biotin). Different concentrations (4.17pM to 41.7nM) of dye-conjugated streptavidin were simultaneously infused through the second microfluidic channels, which lie 90° from the first microfluidic channels. The florescent intensity at the crossover areas showed good agreement with simulations, with sharp ZnO NWs exhibiting the largest dynamic range and the highest fluorescent intensity. We further characterize correspondent protein detection using sharp ZnO NWs. The surfaces of these ZnO NWs were modified with mouse immunoglobulin G (IgG), infused through the second microfluidic channels with dye-conjugated (Alexa 546) anti-mouse IgG in different concentrations. Concentrations ranging from 417fM to 41.7nM can be resolved using sharp ZnO NWs. Finally, multiple protein detection was demonstrated using a five-by-eight microfluidic channel array. Fluorescence images present clear multiple detections at the crossover areas when using the sharp ZnO NWs for simultaneous dye-conjugated anti-mouse IgG and dye-conjugated anti-rabbit IgG (Alexa 647) detection.

High-throughput approaches for profiling the 5′ ends of RNA degradation intermediates on a genome-wide scale are frequently applied to analyze and validate cleavage sites guided by microRNAs (miRNAs). However, the complexity of the RNA degradome other than miRNA targets is currently largely uncharacterized, and this limits the application of RNA degradome studies. We conducted a global analysis of 5′-truncated mRNA ends that mapped to coding sequences (CDSs) of Arabidopsis thaliana, rice (Oryza sativa), and soybean (Glycine max). Based on this analysis, we provide multiple lines of evidence to show that the plant RNA degradome contains in vivo ribosome-protected mRNA fragments. We observed a 3-nucleotide periodicity in the position of free 5′ RNA ends and a bias toward the translational frame. By examining conserved peptide upstream open reading frames (uORFs) of Arabidopsis and rice, we found a predominance of 5′ termini of RNA degradation intermediates that were separated by a length equal to a ribosome-protected mRNA fragment. Through the analysis of RNA degradome data, we discovered uORFs and CDS regions potentially associated with stacked ribosomes in Arabidopsis. Furthermore, our analysis of RNA degradome data suggested that the binding of Arabidopsis ARGONAUTE7 to a noncleavable target site of miR390 might directly hinder ribosome movement. This work demonstrates an alternative use of RNA degradome data in the study of ribosome stalling.

BACKGROUND: Bamboo is an economically important market vegetable and processed food product in Asia. An accelerated growth rate and increased photosynthesis efficiency would be valuable agronomic traits in commercial bamboo culture. Tissue culture-derived albino mutants can be used as experimental material to investigate this phenomenon, but the current body of genetic information available on bamboo is very limited. RESULTS: A cDNA library was constructed from in vitro shoots of Bambusa edulis Munro and subsequently used in a bamboo microarray analysis to investigate the gene profiles of three albino mutants (ab, ab1, ab2) cultured under light/dark and dark conditions. Analysis of the array data suggested that no gene transcript accumulation was significantly upregulated, but that transcript accumulation of 24 genes was downregulated by

cDNAs specifically expressed at the basidiome stage were isolated by using PCR-selected cDNA subtraction in order to study gene regulation during porous-hymenium basidiomatal formation in Antrodia cinnamomea. blastx results suggested that most of the expressed sequence tags (52.4-69.5%) had no significant protein homology to genes from other published living things. cDNAs particularly expressed at different growing conditions were identified using cDNA microarray analysis. Reverse transcriptase PCR analyses confirmed that the clone putative to P-type ATPase, various cytochrome P450s and some unknown genes were abundant at natural basidiomes while endoglucanase was abundant at the tissue from artificial medium.

1-Aminocyclopropane-1-carboxylic acid (ACC) oxidase catalyzes the oxidation of ACC to the gaseous plant hormone, ethylene. Although the enzyme does not contain a typical N-terminal consensus sequence for the transportation across the endoplasmic reticulum (ER), it has recently been shown to locate extracellularly by immunolocalization study. It was of interest to examine whether the enzyme contains a signal peptide that is overlooked by structure prediction. We observed that the in vitro translated apple ACC oxidase was not co-processed or imported by the canine pancreatic rough microsomes, a system widely used to identify signal peptide for protein translocation across ER, suggesting that apple ACC oxidase does not contain a signal peptide for ER transport. A highly specific polyclonal antibody raised against the recombinant apple ACC oxidase was used to examine the subcellular localization of the enzyme in apple fruit (Malus domestica, var. Golden Delicious). The location of ACC oxidase appeared to be mainly in the cytosol of the apple fruit pericarp tissue as was demonstrated by electron microscopy using immunogold-labeled antibodies. The pre-immune serum or pre-climacteric fruit control gave essentially no positive signal. Based on these observations, we conclude that ACC oxidase is a cytosolic protein.

Ethylene is known to play an essential role in mediating hypoxic responses in plants. Here, we show that in addition to regulating hypoxic responses, ethylene also regulates cellular responses in the reoxygenation stage after anoxic treatment in Arabidopsis. We found that expression of several ethylene biosynthetic genes and ethylene-responsive factors, including ERF1 and ERF2, was induced during reoxygenation. Compared with the wild type, two ethylene-insensitive mutants (ein2-5 and ein3eil1) were more sensitive to reoxygenation and displayed damaged phenotypes during reoxygenation. To characterize the role of ethylene, we applied microarray analysis to Col-0, ein2-5 and ein3eil1 under reoxygenation conditions. Our results showed that gene transcripts involved in reactive oxygen species (ROS) detoxification, dehydration response and metabolic processes were regulated during reoxygenation. Moreover, ethylene signalling may participate in regulating these responses and maintaining the homeostasis of different phytohormones. Our work presents evidence that ethylene has distinct functions in recovery after anoxia and provides insight into the reoxygenation signalling network.

It has been proposed that 1-aminocyclopropane-1-carboxylic acid (ACC) oxidase catalyzes the oxidation of ACC to ethylene via N-hydroxyl-ACC as an intermediate. However, due to its chemical instability the putative intermediate has never been isolated. Here, we have shown that a purified recombinant ACC oxidase can utilize α-aminoisobutyric acid (AIB), an analog of ACC, as an alternative substrate, converting AIB into CO2, acetone, and ammonia. We chemically synthesized the putative intermediate compound, N-hydroxyl-AIB (HAIB), and tested whether it serves as an intermediate in the oxidation of AIB. When [1-14C]AIB was incubated with ACC oxidase in the presence of excess unlabeled HAIB as a trap, no labeled HAIB was detected. By comparing the acetone production rates employing HAIB and AIB as substrates, the conversion of HAIB to acetone was found to be much slower than that of using AIB as substrate. Based on these observations, we conclude that ACC oxidase does not catalyze via the N-hydroxylation of its amino acid substrate. ACC oxidase also catalyzes the oxidation of other amino acids, with preference for the d -enantiomers, indicating a stereoselectivity of the enzyme.

Ethylene is known to play an essential role in mediating hypoxic responses in plants. Here, we show that in addition to regulating hypoxic responses, ethylene also regulates cellular responses in the reoxygenation stage after anoxic treatment in Arabidopsis. We found that expression of several ethylene biosynthetic genes and ethylene-responsive factors, including ERF1 and ERF2, was induced during reoxygenation. Compared with the wild type, two ethylene-insensitive mutants (ein2-5 and ein3eil1) were more sensitive to reoxygenation and displayed damaged phenotypes during reoxygenation. To characterize the role of ethylene, we applied microarray analysis to Col-0, ein2-5 and ein3eil1 under reoxygenation conditions. Our results showed that gene transcripts involved in reactive oxygen species (ROS) detoxification, dehydration response and metabolic processes were regulated during reoxygenation. Moreover, ethylene signalling may participate in regulating these responses and maintaining the homeostasis of different phytohormones. Our work presents evidence that ethylene has distinct functions in recovery after anoxia and provides insight into the reoxygenation signalling network.

A fragment of Staphylococcus epidermidis lipase gene (Lys-303 to Lys-688) was inserted into plasmid pET-20b(+). The resulting C-terminal His-tagged recombinant protein (43 kDa) was overexpressed in Escherichia coli BL21(DE3) as a highly active lipase and was purified with nickel-coupled resin. Putative catalytic sites were determined by site-directed mutagenesis. Mutant enzymes (S418C and H648K) lost enzyme activities, which strongly suggests that the proposed residues of Ser-418 and His-648 are involved in catalysis. Site-directed mutagenesis showed that in comparison with wild-type enzyme, the M419A and V649l enzymes showed a 2.0- and 4.0-fold increase in the kcat/Km′ respectively, but the M419l, M419Q, V649A, and V649L variants lost enzyme activities. The wild-type enzyme and the V649l mutant favored the hydrolysis of p-nitrophenyl esters of butyrate, but the M419A favored decanoate. The results suggested that the amino acid residues (Met-419 and Val-649), following the catalytic triad, could affect the substrate specificity and/or catalytic efficiency.

cDNAs specifically expressed at the basidiome stage were isolated by using PCR-selected cDNA subtraction in order to study gene regulation during porous-hymenium basidiomatal formation in Antrodia cinnamomea. blastx results suggested that most of the expressed sequence tags (52.4-69.5%) had no significant protein homology to genes from other published living things. cDNAs particularly expressed at different growing conditions were identified using cDNA microarray analysis. Reverse transcriptase PCR analyses confirmed that the clone putative to P-type ATPase, various cytochrome P450s and some unknown genes were abundant at natural basidiomes while endoglucanase was abundant at the tissue from artificial medium.

Various flavor esters were obtained by using recombinant lipases from Staphylococcus epidermidis as a catalyst in an aqueous environment. These esters were enzymatically synthesized to overcome the problems associated with chemical processes. This study showed that the S. epidermidis lipases could catalyze ester synthesis from decyl alcohol and fatty acids of different chain length. The wild-type and mutant lipases (M419A and V649I) could efficiently catalyze the synthesis of decyl alcohol esters of unsaturated fatty acids. In contrast, the yield of decyl laurate was better by wild-type and mutant enzyme V6491, but mutant enzyme M419A only favored the synthesis of decyl myristate. The esterification of oleic acid and various carbon-chain-length alcohols from ethanol to hexadecanol increased up to decanol by wild-type and M419A mutant enzymes and reached an optimum for dodecanol by V6491 mutant enzyme. The enzyme is potentially useful in food industries such as dairy product flavoring.

We have adopted a hypoxic treatment system in which only roots were under hypoxic conditions. Through analyzing global transcriptional changes in both shoots and roots, we found that systemic signals may be transduced from roots to trigger responses in tissues not directly subjected to hypoxia. The molecular mechanisms of such systemic responses under flooding are currently largely unknown. Using ontological categorization for regulated genes, a systemic managing program of carbohydrate metabolism was observed, providing an example of how systemic responses might facilitate the survival of plants under flooding. Moreover, a proportion of gene expressions that regulated in shoots by flooding was affected in an ethylene signaling mutation, ein2-5. Many systemic-responsive genes involved in the systemic carbohydrate managing program, hormone responses and metabolism, ubiquitin-dependent protein degradation were also affected in ein2-5. These results suggested an important role of ethylene in mediation of hypoxic systemic responses. Genes associated with abscisic acid (ABA) biosynthesis are upregulated in shoots and down regulated in roots. An ABA signaling mutation, abi4-1, affects expression of several systemic responsive genes. These results suggested that regulation of ABA biosynthesis could be required for systemic responses. The implications of these results for the systemic responses of root-flooded Arabidopsis are discussed.