Bryopsis africana and Pyropia kinositae are reported for the first time on the list of Korean marine algal flora based on integrated morphological-molecular study. Bryopsis africana from Korea is recognized with distinct main axes, robust thalli, pinnately and radially branched above, and basally denuded. Phylogenetic analyses revealed that B. africana was placed within a clade of Bryopsis. Bryopsis africana differs from B. corymbosa by 2.7% gene sequence divergence. Pyropia kinositae is characterized by oblong to lanceolate thalli, entire margin, purplish red in color, twice as long as broad cells in transversal section view. Phylogenetic analyses revealed that P. kinositae was placed within a clade of Pyropia. Pyropia kinositae differs from P. tenera by 1.5-1.8%, P. ishigecola by 1.2-1.3%, and P. yezoensis by 1.5-1.8% gene sequence divergence respectively.
Detailed morphological studies and molecular analyses based on plastid-encoded rbcL gene sequences were undertaken on Peyssonnelia species, a poorly known genus from Korea. We report new records for the Korean coast, Peyssonnelia harveyana and P. rumoiana. Peyssonnelia harveyana is chiefly characterized by P. rubra-type anatomy, closely packed perithallial filaments in firm matrix, hypothallial filaments arranged in parallel rows, thalli with appressed margins, hypobasal calcification, and unicellular rhizoids. Peyssonnelia rumoiana is principally characterized by two vegetative features, hypothallial filaments arranged in a polyflabellate layer, and perithallial filaments arising from the whole upper surface of each hypothallial cell (Peyssonnelia rubra-type anatomy). Our rbcL analyses revealed that P. harveynana and P. rumoiana were placed within a clade of Peyssonnelia. We also propose the new combination, Sonderophycus cauliferus comb. nov., for previous Peyssonnelia caulifera. Phylogenetic analyses revealed that our S. cauliferus was placed within a clade of Sonderophycus.
The purpose of this study was to investigate the effect of estrus synchronization to altrenogest regumate (progesterone), PMSG/hCG, and artificial insemination (AI) on galectin-3, FGF-9 gene and protein expression. The morpho-metrical parameters of the endometrium and the number of corpora lutea (CL) were recorded. RNA was isolated from endometrial, oviduct and ovary tissues of non-synchronized (Control; n = 7) and AI synchronized (regumate, PMSG/hCG; n = 7) sows. The total number of CL was higher (P<0.05) in pigs treated with regumate/PMSG/hCG. The content of gelactin-3 and FGF-9 mRNA in pre-embryonic development stages increased on particular days, in control and studied in regumate/PMSG/hCG administered pigs. Gelactin-3 and FGF-9 were affected by regumate/PMSG/hCG treatment in the both pre-embryonic development stages (P<0.001, P<0.05) and encdometrial tissue (P<0.001, P<0.01). The regumate/PMSG/hCG treatment resulted in elevated expression of gelactin-3 (P<0.001) and FGF-9 (P<0.005) in oviduct and ovary tissues in comparison to control sows. Moreover, oviduct amount of gelectin-3 mRNA was higher in regumate/PMSG/hCG sows in comparison to the control group (P<0.05), whereas, expression characteristics of gelactin-3 and FGF-9 were investigated by hematoxylin and eosin stained and immunohistochemical staining. The results showed that galectin-3 and FGF-9 were significantly shown in the endometrium, oviduct and ovary tissues of the regumate/PMSG/ hCG. Presented data show that exogenous hormones administration can affect gene and protein expression in the sow reproductive tract.
Cysteine protease (CP) is one of the well-studied proteolytic enzymes in plants. This class of protease has been implicated in various physiological aspects of developmental stages in plants including seed germination, senescence, and disease immunity. A handful of studies assigned plants cysteine protease in different molecular battlefield under a few selected pathosystems, and initially extricated complex molecular mechanism of resistance. However, its potential use as an agent of resistance to diseases in rice has never been explored. This study demonstrates the function of CP specifically in rice - Xanthomonas oryzae pv. oryzae (Xoo) pathosystem. The CP -encoding full-length cDNA was cloned from Brassica rapa and transformed into japonica rice cv. ‘Gopumbyeo’. The gene was overexpressed under the control of CaMV35S promoter in pFLC vector. Blast analysis of the conserved domain of the gene confirmed its affinity to Peptidase_CIA family. RT-PCR analysis showed that the gene was constitutively expressed in all tissues tested. Regulation of rice resistance through cysteine protease activity is evident in overexpression lines which exhibited an enhanced resistance to four Korean Xoo isolates. Further analyses will be carried out to uncover the specific role of CP in rice-Xoo interaction.
There is a great consideration on rice eating quality aside from improving its tolerance to various stresses. High yielding and pest and disease tolerant rice is highly desirable but it is more commercially important if it also has a high eating quality. There are various factors contributing to the good eating quality of rice. This study focuses on modifying the expression of GBSS1 genes which are responsible for amylopectin and amylose synthesis in rice by using RNAi and antisense techniques. We have developed 40 transgenic plants with RNAi-GBSS1 gene and 60 transgenic lines with antisense-GBSS1 gene. The transgenic plants show diverse amylose contents in rice seed. We selected candidate lines according to PCR, RNA expression and amylose contents. A semi-quantitative RT-PCR was carried out to measure the expression level of GBSS1 gene at several time points after the flowering of transgenic plants. The expression level of GBSS1 gene in rice grains decreases over time and the mRNA expression among the transgenic plants were lower compare to its wild type. In the SEM analysis, the starch granule of wild type Gopumbyeo has very large structures accompanied with small ones around the area. However, the starch structures in transgenic plants were smaller and more uniform in size and shape throughout the viewing area
An increasing preference for good eating quality of rice among consumers has become one of the important considerations in rice breeding. Amylose content of starch is one of the important factors of rice eating quality. Amylose composition is determined by the relative activity of soluble starch synthase (SSS) and granule-bound starch synthase (GBSS). This study focuses on modifying the expression of SSS1 gene which is responsible for amylopectin and amylose synthesis in rice by using RNA interference (RNAi) and antisense technology. The transgenic rice plants showed various amylose content (9-17%) in rice seed. Candidate rice lines were selected according to PCR, RNA expression and amylose contents analyses. A semi-quantitative RT-PCR was carried out to determine the expression level of SSS1 gene at several time points after the flowering of transgenic plants. Downregulation of SSS1 gene in transgenic rices was evident in the decreasing expression in rice grains over time. Accordingly, SEM micrographs analysis revealed uniform size with smooth curves starch granules in downregulation rice lines, in contrast with the non-uniform granules in wild type.
UDP-glucose 4-epimerase (UGE) catalyzes the reversible conversion of UDP-glucose to UDP-galactose. To understand the biological function of UGE from Brassica rapa, the gene hereinafter referred to as was cloned and overexpressed into Japonica rice cv. Gopum. Transcriptional profiling showed that the is specific to stem of rice plant. Morphological evaluation of the overexpression lines revealed altered phenotype characters particularly in panicle length, number of productive tillers and filled spikelets which account for an increase in yield. This remarkable agronomic performance was ascribed to higher photosynthetic rate complemented with higher CO2 assimilation. Interestingly, BrUGE1 did not only improve plant fitness under optimal condition but also under water deficit stress. The enhanced drought tolerance may be due to the induction of soluble sugar which may act as osmolyte to compensate dehydration during drought stress.
In spite of the overwhelming number of cysteine proteases in plants, only a few were substantially investigated. Papain-like cysteine proteases (PLCPs) are commonly implicated to disease immunity in some key pathosystems in plants, such as in tomato – Cladosporium fulvum, potato/tomato – phytopthora infestans, and Arabidopsis – Ralstonia solanacearum, among the few others. This study demonstrates the function of cysteine protease gene cloned form Brassica rapa (BrCP) related to resistance to Xanthomonas oryzae pv. oryzae in transgenic rice lines. The cysteine protease-encoding full-length cDNA was identified and characterized using web-based tools. The gene is 2,267 bp in size with an open reading frame of 1,365 bp that encodes predicted polypeptide of 455 amino acids. Blast analysis of the conserved domain of the gene confirmed its affinity to Peptidase_CIA family. Full-length cDNA of PLCP in Brassica rapa was then cloned and co-overexpressed in rice with HPT marker. Introgression of the gene was confirmed in the transformants through genomic PCR assay. RT-PCR analysis showed that the gene was constitutively expressed and present in all tissues. The overexpression rice lines exhibited an enhanced resistance when screened with four Korean Xoo isolates.
Glutamine synthetase (GS) is an enzyme that plays an essential role in the metabolism of nitrogen by catalyzing the condensation of glutamate and ammonia to form glutamine. Exposure of plants to cadmium (Cd) has been reported to decrease GS activity in maize, pea, bean, and rice. To better understand the function of the GS gene under Cd stress in rice, we constructed a recombinant pART vector carrying the GS gene under the control of the CaMV 35S promoter and OCS terminator and transformed using Agrobacterium tumefaciens. We then investigated GS overexpressing rice lines at the physiological and molecular levels under Cd toxicity. The GS activity along with mRNA expression were found higher in transgenic than in wild type plants. And this is validated by the low malondialdehyde contents observed 10 days after treatment. GS overexpression in rice resulted in the modulation of expression of enzymes responsible for membrane peroxidation, which may result in the sudden death of plants. Our results thus describe the features of a transgenic rice plants with enhanced tolerance to Cd toxicity.
Amylopectin composition is determined by the relative activity of soluble starch synthase (SSS) and granule-bound starch synthase (GBSS). Soluble starch synthase and starch branching enzymes are major determinants for the synthesis of amylopectin while GBSS1 is responsible for amylose synthesis in vivo. The formers are made of linear and branched molecules and the latter is composed of highly branched molecules. To increase the palatability of rice, down-regulation of amylose synthesis by antisense and RNA interference (RNAi) could be excellent and powerful tools for controlling the starch composition which is responsible for grain eating quality. The goal of this study is to generate breeding lines with lower amylose content relative to its wild type. This study also reports the results of the two down-regulating technology in lowering the amylose content of rice grain. Furthermore, this study elucidates the effect of using antisense and RNAi for SSS1 and GBSS1.
Bacterial blight is a serious problem of rice in irrigated and rainfed lowlands. It is caused by Xanthomonas oryzae pv. oryzae (Xoo) which is represented by many pathotypes, making it difficult to control. Plant proteases are important players in immunity acting either in the execution of attack, in signaling cascade or in perception of invader. This study demonstrates the response of cysteine protease (CP) upon interaction with the pathogen. The cysteine protease encoding full-length cDNA was identified and characterized using web-based tools. Conserved domain of the gene revealed its affinity to Peptidase_CIA family. The full-length cDNA of CP in Brassica rapa was then cloned and overexpressed in rice. Insertion of gene was verified in the transformants through PCR assay. Spatiotemporal expression of the gene was performed in transgenic rice. To evaluate the resistance of CP-overexpression lines to Xoo, transgenic plants were inoculated with two races of Xoo. In planta analysis of enzymatic activity of CP was also performed before and after infection by the pathogen.
MYB-like domain (MLD) gene is a transcription factor that plays a diverse role in plant development and in response to abiotic stresses. In this study, we isolated and developed CaMV35S::OsMLD rice lines and determined its expression pattern under abiotic stresses. The MLD has Myb_CC_LHEQLE superfamily similar to most transcription factor genes but with a very unique binding domain of SHLQKYR in the C-terminal region. Overexpressing rice lines showed enhanced tolerance to salinity with elevated mRNA transcript. Additionally, mRNA transcripts were up-regulated by ABA, H2O2 and dehydration stresses. Further investigation in the enhanced tolerance to salinity showed an increased accumulation of proline and a decreased in malondialdehyde contents indicating that OsMLD gene may be involved in the regulation of proline and osmolytes during abiotic stresses. These results showed that OsMLD gene could be used in the development of rice intended for soil with salinity-related problem.
Telomeres are the end of chromosomes and consist of a tandem repeat sequence of (TTAGGG)n and associated proteins. Telomerase is a ribonucleoprotein which act as a template for the synthesis of telomeric DNA. Telomeres are essential for chromosome stability and are related with cell senescence, apoptosis and cancer. Even though telomeres and telomerase have been studied extensively, very little is known about telomere dynamics in embryonic cells. This study was carried out to analyze the telomeres distribution and telomerase activity of chicken cells during embryonic and developmental stages. The target cells for analysing were sperms, ovulated ova, early embryonic cells and the cells from brain, heart, liver, kidney and germinal tissue in fetus. Telomeres distribution on target cells was analyzed by Q-FISH (Quantitation-Fluorescence in situ Hybridization) techniques using a chicken telomere repeat probe. Telomerase activity was performed by TRAP assay (Telomeric repeat Amplification Protocol) with target DNA. In results, the telomeres of chicken were found at the ends of all chromosomes. In addition, chicken had interstitial telomeres on chromosomes 1, 2 and 3. Telomerase activity was highly detectable in early embryonic cells, germinal tissues and kidney cells. Whereas telomerase activity was gradually down-regulated when the organs, including brain, heart, and liver, were developed from embryos. In the distribution of telomeric DNA on the embryonic and developmental stages, most of the cells was gradually decreased in telomere quantity during ontogenesis.