Plant serine carboxypeptidase-like acyltransferases (SCPL-AT) have similar structural characteristics and high homology compared to the serine carboxypeptidase. They can transfer the acyl from acyl glucose esters to many natural products, participate in the acylation modification of plant secondary metabolites, enrich the structural diversity of natural products, and improve the physicochemical properties such as water solubility and stability of compounds. This review summarizes the structural characteristics, catalytic mechanism, functional characterization, and biocatalytic applications of SCPL-AT from plants. This will help to promote the functional characterization of these acyltransferase genes and the biosynthesis of useful plant secondary metabolites by synthetic biotechnology.
Acylation ; Acyltransferases/metabolism* ; Carboxypeptidases/metabolism* ; Plants/enzymology*

There exists many kinds and a huge number of terpenoid in medicinal plants, which show a wide range of pharmacological activities. 3-Hydroxy-3-metllylglutaryl coenzyme A reductase(HMGR) is a key rate-limiting enzyme in terpenoid biosynthetic pathway . HMGR plays an important role in the regulation of secondary metabolism of the terpenoid. The paper summarized the biological function and the catalytic mechanism of HMGR, the cloning and the structure of the gene as well as its research progress in some medicinal plants.
Hydroxymethylglutaryl CoA Reductases ; metabolism ; Plants, Medicinal ; enzymology ; Terpenes ; metabolism

Type III polyketide synthases (PKSs) from plants produce a variety of plant secondary metabolites with notable structural diversity and biological activity. These metabolites not only afford plants the ability to defend against pathogen attack and other external stresses, but also exhibit a wide range of biological effects on human health. Several plant PKSs have been identified and studied in recent years. This paper summarized what was known about plant PKSs and some of their aspects such as molecular structure, reaction mechanisms, gene expression and regulation, and transgenic engineering. The review provides information for manipulating polyketide formation and further increasing the scope of polyketide biosynthetic diversity, as well as new avenues for developing transgenic engineering of type III PKSs.
Catalysis ; Plants ; enzymology ; Polyketide Synthases ; chemistry ; classification ; metabolism ; Protein Engineering

P1B-ATPases are a group of proteins that can transport heavy metal ions across membranes by hydrolyzing ATP and they are a subclass of the P-type ATPase family. It was found that P1B-ATPases are mainly responsible for the active transport of heavy metal ions in plants and play an important role in the regulation of heavy metal homeostasis in plants. In this paper, we dissusses the mechanism of P1B-ATPases from the structure and classification of P1B-ATPases, and review the current research progress in the function of P1B-ATPases, in order to provide reference for future research and application of P1B-ATPases in improving crop quality and ecological environment management.
Adenosine Triphosphatases/metabolism* ; Biological Transport ; Metals, Heavy ; Plants/enzymology*

Flavonoids are a group of secondary metabolites found in plants. They have many pharmacological functions and play an important role in Chinese sumac( Rhus chinensis),which is a well-known traditional Chinese medicinal plant. Chalcone isomerase( CHI,EC 5. 5. 1. 6) is one of the key enzymes in the flavonoids biosynthesis pathway. In this paper,the full-length c DNA sequence encoding the chalcone isomerase from R. chinensis( designated as Rc CHI) was cloned by RT-PCR and rapid-amplification of c DNA Ends( RACE). The Rc CHI c DNA sequence was 1 058 bp and the open reading frame( ORF) was 738 bp. The ORF predicted to encode a 245-amino acid polypeptide. Rc CHI gene contained an intron and two exons. The sequence alignments revealed Rc CHI shared47. 1%-71. 6% identity with the homologues in other plants. Real-time PCR analysis showed that the total flavonoid levels were positively correlated with tissue-specific expressions of Rc CHI mRNA in different tissues. The recombinant protein was successfully expressed in an Escherichia coli strain with the p GEX-6 P-1 vector. In this paper,the CHI gene was cloned and characterized in the family of Anacardiaceae and will help us to obtain better knowledge of the flavonoids biosynthesis of the flavonoid compounds in R. chinensis.
Cloning, Molecular ; DNA, Complementary ; Flavonoids ; biosynthesis ; Intramolecular Lyases ; genetics ; Plants, Medicinal ; enzymology ; genetics ; Rhus ; enzymology ; genetics

OBJECTIVETo explore the identity and phylogenetic relationships among the three medicinally important species of Sphaerostephanos from South India using isozymic profile.

METHODSThe young fronds were homogenized with 3.5 mL of ice-cold homogenizing buffer in a pre-chilled pestle and mortar. The supernatant was subjected to electrophoresis as described by Anbalagan poly acrylamide gel electrophoresis. Staining solutions for isoperoxidase was prepared as per Smila method for the detection of isoenzymes.

RESULTSA total of six different bands in five different positions with different molecular weight/Rf values and four active zones have been observed in the isoperoxidase enzyme system of Sphaerostephanos. Only one band with MW/Rf 0.399 is common to two different species i.e. Sphaerostephanos arbuscula (S. arbuscula) and Sphaerostephanos unitus (S. unitus). Among the remaining four bands, two bands (Rf. 0.23, 0.47) are present in Sphaerostephanos subtruncatus (S. subtruncatus) and one distinct band has been observed individually in S. arbuscula (Rf. 0.507) and S. unitus (Rf. 0.56).

CONCLUSIONSThe present preliminary molecular study through isozymic analysis shows the identity of all the three species and the present results confirm distinctness of these three species based on macro-micromorphology, phytochemistry and cytology.

Electrophoresis, Polyacrylamide Gel ; India ; Isoenzymes ; analysis ; Peroxidases ; analysis ; Plants, Medicinal ; classification ; enzymology ; Staining and Labeling ; Tracheophyta ; classification ; enzymology

Metagenomes from uncultured microorganisms are rich resources for novel enzyme genes. The methods used to screen the metagenomic libraries fall into two categories, which are based on sequence or function of the enzymes. The sequence-based approaches rely on the known sequences of the target gene families. In contrast, the function-based approaches do not involve the incorporation of metagenomic sequencing data and, therefore, may lead to the discovery of novel gene sequences with desired functions. In this review, we discuss the function-based screening strategies that have been used in the identification of enzymes from metagenomes. Because of its simplicity, agar plate screening is most commonly used in the identification of novel enzymes with diverse functions. Other screening methods with higher sensitivity are also employed, such as microtiter plate screening. Furthermore, several ultra-high-throughput methods were developed to deal with large metagenomic libraries. Among these are the FACS-based screening, droplet-based screening, and the in vivo reporter-based screening methods. The application of these novel screening strategies has increased the chance for the discovery of novel enzyme genes.
Animals ; Bacteria ; enzymology ; Enzymes ; genetics ; Gene Library ; High-Throughput Screening Assays ; methods ; Metagenome ; genetics ; Metagenomics ; methods ; Plants ; enzymology

Genetic modification of barley variety can be an efficient way to improve beer quality. The objective of this study was to understand the effect of trxS gene on hydrolases activities in transgenic and non-transgenic barley seeds. The results showed that alpha-amylase, free beta-amylase and limit dextrinase activity were increased in transgenic seeds in comparison with non-transgenic seeds. Sulfhydryl content of protein in transgenic seeds was also higher than that in non-transgenic seeds, suggesting that trxS gene could express in barley seeds, which opens a new way for breeding new barley varieties to improve beer quality.
Germination ; genetics ; Glucosyltransferases ; metabolism ; Hordeum ; enzymology ; genetics ; Plants, Genetically Modified ; enzymology ; genetics ; Seeds ; enzymology ; genetics ; Sulfhydryl Compounds ; metabolism ; Thioredoxins ; genetics ; alpha-Amylases ; metabolism ; beta-Amylase ; metabolism

The open reading frame of Spinacia oleracea Betaine Aldehyde Dehydrogenase (SoBADH) was retrieved from Spinacia oleracea and inserted into the Agrobacterium tumefaciens binary vector pBin438, which was driven by CaMV35S promoter, and produced the new binary vector pBSB. A. tumefaciens LBA4404 carrying this plasmid was used in genetic transformation of plants. Forty-five primary transgenic plants were detected by PCR and verified by the Southern blotting from 65 regenerated plants, of which 27 transgenic plants had only one copy of T-DNA. The Northern blotting and Western blotting analysis indicated that the SoBADH gene had been transcribed mRNA and expression protein in the transgenic cotton lines. The testing of SoBADH activity of transgenic plant leaves showed that the enzyme activity was much higher than that of the non-transgenic cotton. The growth of transgenic plants was well under the salinity and freezing stress, whereas the non-transgenic plant grew poorly and even died. Challenging with salinity, the height and fresh weight of transgenic plants was higher compared with those of non-transgenic plants. Under the freezing stress, the relative conductivity of leaf electrolyte leakage of the transgenic cotton lines was lower than that of non-transgenic plants. These results demonstrated that the SoBADH gene could over express in the exogenous plants, and could be used in genetic engineering for cotton stress resistance.
Adaptation, Physiological ; Betaine-Aldehyde Dehydrogenase ; biosynthesis ; genetics ; Cold Temperature ; Gossypium ; enzymology ; genetics ; Plants, Genetically Modified ; enzymology ; genetics ; Salinity ; Spinacia oleracea ; enzymology ; genetics ; Stress, Physiological ; genetics

Plant can produce reactive oxygen species (ROS) in normal physiological activity. However, ROS can increase dramatically by environmental stress. The increase may break the ROS balance in the plant. To control ROS levels in plants, an antioxidant system is needed to protect the cell. This paper introduced the types and functions of antioxidant enzymes, and studied the effects of plant and environmental factors on the activities of antioxidant enzymes. At last, the paper discussed the research hot fields of the effect of environmental stress on antioxidant enzymes, and gave the research strategies to the problems which happened in the studies.
Antioxidants ; metabolism ; Ecosystem ; Oxidative Stress ; Plant Proteins ; metabolism ; Plants ; enzymology ; metabolism ; Reactive Oxygen Species ; metabolism