Chemical Oxygen Demand Reduction Using the algae Dunaliella primolecta and Chlorella vulgaris

Farm industry wastewater is characterized by high organic materials and by high chemical oxygen demand (COD). Farms with large livestock and poultry operations can be a major source of wastewater thus a major concern for effective environmental and industrial management. Effective environmental and industrial management are high in cost therefor biofuels produced from plants have a potential of replacing a portion of fossil fuel consumption with a renewable efficient alternative. Due to California’s water crisis in the recent years, it is questioned if a biological treatment system that uses algal growth to create renewable energy in the form of biodiesel is able to remove polluting nutrients and greenhouse gases from dairy wastewater

Early development of the root-knot nematode Meloidogyne incognita

Background: Detailed descriptions of the early development of parasitic nematodes are seldom available. The embryonic development of the plant-parasitic nematode Meloidogyne incognita was studied, focusing on the early events. Results: A fixed pattern of repeated cell cleavages was observed, resulting in the appearance of the six founder cells 3 days after the first cell division. Gastrulation, characterized by the translocation of cells from the ventral side to the center of the embryo, was seen 1 day later. Approximately 10 days after the first cell division a rapidly elongating two-fold stage was reached. The fully developed second stage juvenile hatched approximately 21 days after the first cell division. Conclusions: When compared to the development of the free-living nematode Caenorhabditis elegans, the development of M. incognita occurs approximately 35 times more slowly. Furthermore, M. incognita differs from C. elegans in the order of cell divisions, and the early cleavage patterns of the germ line cells. However, cytoplasmic ruffling and nuclear migration prior to the first cell division as well as the localization of microtubules are similar between C. elegans and M. incognita.This work was funded by grants from the California Agricultural Research Initiative (grant #: ARI/CATI/Calderón-Urrea/Cell Death/03-2-006-31), the College of Science and Mathematics at Fresno State, the California State University Program for Education and Research in Biotechnology (CSUPERB), and the RIMI Facility at Fresno State (development of this facility was funded by NIH-NIMHD grant “Research Infrastructure for Minority Institutions P20MD002732”)

Detection of Salmonella enterica, Escherichia coli O157 and Listeria monocytogenes through bead based Magpix® fluidics

The research is testing the limits of detection and multiplexing with the use of three pathogens with the machine created from Luminex called Magpix. The pathogens are Salmonella enterica, Listeria monocytogenes, and Escherichia Coli O157. The gene that is being focused on for each pathogen is invA for Salmonella, hlyA for listeria, and hlyA for Escherichia Coli. In this research, we started with prepared probes that were attached to the magnetic microsphere beads. Then we extracted and amplify the DNA. Furthermore, the probes were combined to the amplified DNA and used this in Magpix which gave a corresponding MFI value

Selection and validation of reference genes for RT-qPCR analysis in potato under abiotic stress

Abstract Background Real-time quantitative PCR (RT-qPCR) is the most commonly used method for accurately detecting gene expression patterns. As part of RT-qPCR analysis, normalization of the data requires internal control gene(s) that display uniform expression under different biological conditions. However, no invariable internal control gene exists, and therefore more than one reference gene is needed to normalize RT-qPCR results. Identification of stable reference genes in potato will improve assay accuracy for selecting stress-tolerance genes and identifying molecular mechanisms conferring stress tolerance in this species. Results In the experiment, we assessed the expression of eight candidate internal control genes, namely elongation factor-1alpha (EF1α), actin, tubulin, glyceraldehyde-3-phosphate dehydrogenase (GAPDH), adenine phosphoribosyl transferase (APRT), 60S ribosomal protein L8 (L8), Cullin 3A (CUL3A), and exocyst complex component sec3 (sec3), in a diverse set of potato samples representing drought stress and osmotic stress challenges, and using geNorm, NormFinder, BestKeeper and RefFinder softwares. Conclusions The results indicated that EF1α and sec3 were the most stably expressed genes in the potato under drought and osmotic stress conditions. This work will facilitate future work on gene expression studies in potato and also benefit other species of the Solanaceae, such as tomato

Trichoderma longibrachiatum TG1 increases endogenous salicylic acid content and antioxidants activity in wheat seedlings under salinity stress

Several studies have reported the deleterious effects of excessive salt stress on Triticum aestivum L. seedlings. Seed pretreatment with exogenous salicylic acid (SA) enhances plants to tolerate salt stress. Herein, the present study aims to investigate the potential of plant-growth-promoting fungus Trichoderma longibrachiatum (TG1) to increase the plant growth and enhance the salicylic acid (SA) contents and antioxidants activity in wheat seedlings under different concentrations of salt stress. Wheat seeds were pretreated in TG1 spore suspension before exposure to different salt stresses. Compared with 0, 50, 100, 150 salt stresses, the TG1 and NaCl increased the wheat seeds germination rate, germination potential and germination index significantly; the shoot height and root length were increased by an average of 39.45% and 29.73%, respectively. Compared to NaCl stress across the four concentrations (0, 50, 100, and 150 mM), the TG1 treated wheat seedlings increased SA concentration and phenylalanine ammonia-lyase activity (PAL) by an average of 55.87% and 24.10% respectively. In addition, the TG1+NaCl-treated seedlings increased superoxide dismutase (SOD), peroxidases (POD), and catalase (CAT) activities in the shoot by an average of 47.68%, 23.68%, and 38.65% respectively compared to NaCl-stressed seedlings. Significantly, the genes, SOD, CAT, and POD were relatively up-regulated in the salt-tolerant TG1-treated seedlings at all NaCl concentrations in comparison to the control. Wheat seedlings treated with TG1+NaCl increased the transcript levels of SOD, POD and CAT by 1.35, 1.85 and 1.04-fold at 50 mM NaCl concentration, respectively, compared with 0 mM NaCl concentration. Our results indicated that seeds pretreatment with TG1 could increase endogenous SA of plants and promote seedling growth under salt stress by improving enzymatic antioxidant activities and gene expression

Overexpression of sense and antisense ced-9 in tobacco plants confers resistance to Meloidogyne incognita

Transgenic tobacco plants expressing the Caenorhabditis elegans programmed cell death gene ced-9, in both sense and antisense orientations, were produced using Agrobacteriumtumefaciens-mediated transformation. The generated transgenic tobacco plants were tested for resistance to the root-knot nematode Meloidogyne incognita by measuring gall formation, size of galls generated, and the ability of juvenile-2 (J2) to hatch. Results showed that expression of ced-9 gene in either sense (ced-9F) or antisense (ced-9R) orientation in hemizygous transgenic tobacco plants induced prevention of M. incognita proliferation (as measured by gall number reduction) and J2 hatching. Furthermore, the results also showed that ced-9R in homozygous transgenic tobacco plants prevented J2 hatching, whereas ced-9F homozygous transgenic tobacco plants lost nematicidal function. Although our study demonstrates that expression of either ced-9R or ced-9F genes in tobacco plants significantly reduces infection by M. incognita, further investigation is required to understand the specific mechanisms involved for this control. It is possible that the nematode resistance seen with both sense (ced-9F) and antisense (ced-9R) sequences is the result of two independent mechanisms, one acting on invading nematodes and the other acting during embryogenesis of M. incognita, ultimately resulting in plant protection. © 2012 Korean Society for Plant Biotechnology and Springer.This work was funded by grants from the National Institute of General Medical Sciences (MBRS-SCORE Grant #: S06-GM61223), the California Agricultural Research Initiative (Grant #: ARI/CATI/Calderon-Urrea/Cell Death/03-2-006-31) and the National Institute on Minority Health and Health Disparities (NIMHD) (Grant #: Research Infrastructure for Minority Institutions P20MD002732) to A.C.-U., Faculty Sponsored Student Research Awards (to F.Y. and T.P.) from the College of Science and Mathe- matics at CSU Fresno, an Educational Research Project Grant from the Associated Students of CSU Fresno (to F.Y.), a Graduate Student Research Merit Award and a Graduate Division Travel Award from CSU Fresno (to F.Y.), a Student Travel Award from CSUPERB (to F.Y.), and a Cobb Student Travel Award from the Society of Nematologists (to F.Y.). The authors thank Dr. Paul Crosbie for critically reading and commenting on the manuscript.Peer Reviewe

Lateral Root Development in Potato Is Mediated by Stu-mi164 Regulation of NAC Transcription Factor

The NAC designation is derived from petunia (Petunia hybrida) gene NO APICAL MERISTEM (NAM) and Arabidopsis genes ATAF1/ATAF2 and CUP-SHAPED COTYLEDON2 (CUC2), which belongs to the family of plant-specific transcription factors (TFs), and plays important role in plant development processes, such as response to biotic and abiotic stress, and hormone signaling. MicroRNAs (miRNAs) are a class of small, non-coding endogenous RNAs which play versatile and significant role in plant stress response and development via negatively affecting gene expression at a post-transcriptional level. Here, we showed that Stu-mi164 had a complementary sequence in the CDS sequence of potato NAC TFs, and that NAC expression exhibited significant differences under osmotic stress. We measured expression levels of the Stu-mi164 target gene StNAC262 between control and PEG-treated plants using real-time PCR, and the results demonstrated that they had inverse relationship. We suggested that Stu-miR164 might drive overexpression of NAC gene under osmotic stress in potato. To confirm the regulation of NAC TFs by Stu-mi164, we developed transgenic plants, using Agrobacterium tumefaciens–mediated transformation, of the potato cultivars “Gannongshu 2” and “Kexin 3” overexpressing the Stu-mi164 or the TF StNAC262. Real-time PCR analysis of transgenic potato plants under osmotic (PEG) stress, showed that potato plants overexpressing Stu-mi164 had reduced expression of StNAC262 and their osmotic resistance decreased. Furthermore, these plants had low number of lateral roots although the same length as the control. Our findings support the regulatory role of Stu-miRNAs in controlling plant response to osmotic stress via StNAC262

Expression of the cell death protein CED-4 of Caenorhabditis elegans in transgenic tobacco plants confers resistance to Meloidogyne incognita

Plant parasitic nematodes are devastating to agricultural production. Recent estimates indicate that losses due to nematode infestation can reach US$ 125 billion per year worldwide. Further aggravating the problem is the use of chemicals, such as methyl bromide. Even though methyl bromide is still the best tool currently available to combat nematode infestation, it has been targeted by international treaties for elimination from worldwide agriculture due to its deleterious impact on the environment. Therefore, alternatives are urgently needed to eliminate the threat of both parasitic nematodes and hazardous pesticides. In an attempt to develop novel strategies for nematode control, we produced and characterized transgenic tobacco plants constitutively expressing the ced-4 gene from Caenorhabditis elegans and exposed homozygous lines to the plant parasitic nematode Meloidogyne incognita. Five transgenic lines tested showed a significant reduction in the number of nematode-induced galls formed. These tolerant tobacco lines displayed high levels of ced-4 expression (determined via a competitive reverse transcription-PCR assay) and the presence of CED-4 (determined by Western blot analysis with anti-CED-4 antibodies). In addition, protein extracts from transgenic ced-4 plants restored CED-3 activity of the ced-4 mutant C. elegans protein extracts to wild-type levels, indicating that the CED-4 protein produced in these transgenic plants is functional. We suggest that programmed cell death genes may provide an alternative to control plant parasitic nematodes. © 2012 Korean Society for Plant Biotechnology and Springer.This work was funded by grants from the National Institute of General Medical Sciences (MBRS-SCORE grant no.: S06-GM61223), the California Agricultural Research Initiative (grant no.: ARI/CATI/Calderón-Urrea/Cell Death/03-2-006-31), and the National Institute on Minority Health and Health Disparities (NIMHD) (grant no.: Research Infrastructure for Minority Institutions P20MD002732) to A.C.-U. R.T.G was recipient of a MAI fellowship from the U.S. EPA and C.T. was recipient of a RISE fellowship from NIH (MBRS-RISE grant no.: R25 GM071423).Peer Reviewe

Cell Cycle Arrest of Stamen Initials in Maize Sex Determination

The maize sex determination pathway results in the arrest of stamen in ear spikelets and the abortion of pistils in both the tassel spikelets and in the secondary florets of ear spikelets. Arrested stamen cells showed no signs of DNA fragmentation, an absence of CYCLIN B expression, and an accumulation of the negative cell cycle regulator WEE1 RNA

Grafting-enhanced tolerance of cucumber to toxic stress is associated with regulation of phenolic and other aromatic acids metabolism

Toxic stress caused by autotoxins is a common phenomenon for cucumber under monoculture condition. A previous study demonstrated that grafting could enhance the resistance of cucumber to cinnamic acid (CA) stress, but the underlying mechanism behind this enhanced resistance is still unclear. In the present study, we reconfirmed the stronger resistance of grafted rootstock (RG) compared to the non-grafted (NG) cucumber as measured though plant biomass accumulation. In addition, we focused on the phenolic and other aromatic acids metabolism in hydroponic culture model system using a combination of qRT-PCR (to measure gene expression of relevant genes) and HPLC (to detect the presence of phenolic and other aromatic acids). The results showed that the exogenous CA lead to the expression of four enzymes involved in phenolic and other aromatic acids biosynthesis, and a larger increase was observed in grafted rootstock (RG). Specifically, expression of six genes, involved in phenolic and other aromatic acids biosynthesis (PAL, PAL1, C4H, 4CL1, 4CL2 and COMT), with the exception of 4CL2, were significantly up-regulated in RG but down-regulated in NG when exposed to CA. Furthermore, six kinds of phenolic and other aromatic acids were detected in leaves and roots of NG and RG cucumber, while only benzoic acid and cinnamic acid were detected in root exudate of all samples. The CA treatment resulted in an increase of p-hydroxybenzonic acid, benzoic acid and cinnamic acid contents in RG cucumber, but decrease of p-coumaric acid and sinapic acid contents in NG cucumber. Surprisingly, the type and amount of phenolic and other aromatic acids in root exudate was improved by exogenous CA, particularly for RG cucumber. These results suggest that a possible mechanism for the stronger resistance to CA of RG than NG cucumber could involve the up-regulation of key genes involved in phenolic and other aromatic acids metabolism, and that the excessive phenolic compounds released to surroundings is a result of the accumulation of phenolic compounds in a short time by the plant under stress