Catalase (CAT) Gene Family in Oil Palm (Elaeis guineensis Jacq.): Genome-Wide Identification, Analysis, and Expression Profile in Response to Abiotic Stress.

Catalases (CATs) play crucial roles in scavenging H2O2 from reactive oxygen species, controlling the growth and development of plants. So far, genome-wide identification and characterization of CAT genes in oil palm have not been reported. In the present study, five EgCAT genes were obtained through a genome-wide identification approach. Phylogenetic analysis divided them into two subfamilies, with closer genes sharing similar structures. Gene structure and conserved motif analysis demonstrated the conserved nature of intron/exon organization and motifs among the EgCAT genes. Several cis-acting elements related to hormone, stress, and defense responses were identified in the promoter regions of EgCATs. Tissue-specific expression of EgCAT genes in five different tissues of oil palm was also revealed by heatmap analysis using the available transcriptome data. Stress-responsive expression analysis showed that five EgCAT genes were significantly expressed under cold, drought, and salinity stress conditions. Collectively, this study provided valuable information on the oil palm CAT gene family and the validated EgCAT genes can be used as potential candidates for improving abiotic stress tolerance in oil palm and other related crops.

Yan-Hou-Qing formula attenuates ammonia-induced acute pharyngitis in rats via inhibition of NF-κB and COX-2.

BACKGROUND: Yan Hou Qing (YHQ) is a Chinese medicinal formula designed to alleviate sore throat symptoms, but underlying mechanism of YHQ treatment for pharyngitis is poorly defined up to now. METHODS: In this study, the modulation of YHQ on pharyngitis is investigated in ammonia-induced acute pharyngitis rat models. After treatment with YHQ or dexamethasone respectively for five consecutive days, all rats were sacrificed for biomolecular and histopathologic study. Protein expressions of MAPKs, NF-κB, COX-2 and 5-LOX in pharyngitis tissue were evaluated by western blot analysis and the levels of TNF-α, IL-6, prostaglandin (PG) E2, leukotrienes (LT)-B4 and LT-D4 in pharyngeal tissue were measured via ELISA assay. Evans blue (EB) dye exudation test was performed parallelly to assess the integrity of pharyngeal tissue. RESULTS: Compared with normal control group, EB dye exudation, and inflammatory cytokines in the model group were significantly increased, and the pharynx tissue was obviously infiltrated by inflammatory cells. YHQ treatment improved the inflammatory infiltrate in pharyngeal tissue, and reduced EB dye exudation in AP rat models. The up-regulated TNF-α and IL-6 in pharyngeal tissue of AP were significantly reduced by YHQ through inhibition of phosphorylation of p38, Erk and NF-κB. YHQ treatment also reversed the increased level of PGE2 through down-regulation of COX-2. CONCLUSIONS: YHQ formula attenuated the pharyngitis related symptoms via suppression of COX-2 and phosphorylation of p38, Erk and NF-κB (p65).

Using a trait-based approach to optimize mixotrophic growth of the red microalga Porphyridium purpureum towards fatty acid production.

BACKGROUND: Organic carbon sources have been reported to simultaneously increase the growth and lipid accumulation in microalgae. However, there have been no studies of the mixotrophic growth of Porphyridium purpureum in organic carbon media. In this study, three organic carbon sources, glucose, sodium acetate, and glycerol were used as substrates for the mixotrophic growth of P. purpureum. Moreover, a novel trait-based approach combined with Generalized Additive Modeling was conducted to determine the dosage of each organic carbon source that optimized the concentration of cell biomass or fatty acid. RESULTS: A 0.50% (w/v) dosage of glucose was optimum for the enhancement of the cell growth of P. purpureum, whereas sodium acetate performed well in enhancing cell growth, arachidonic acid (ARA) and eicosapentaenoic acid (EPA) content, and glycerol was characterized by its best performance in promoting both cell growth and ARA/EPA ratio. The optimum dosages of sodium acetate and glycerol for the ARA concentration were 0.25% (w/v) and 0.38% (v/v), respectively. An ARA concentration of 211.47 mg L-1 was obtained at the optimum dosage of glycerol, which is the highest ever reported. CONCLUSIONS: The results suggested that a comprehensive consider of several traits offers an effective strategy to select an optimum dosage for economic and safe microalgae cultivation. This study represents the first attempt of mixotrophic growth of P. purpureum and proved that both biomass and ARA accumulation could be enhanced under supplements of organic carbon sources, which brightens the commercial cultivation of microalgae for ARA production.

Light intensity and N/P nutrient affect the accumulation of lipid and unsaturated fatty acids by Chlorella sp.

In this study, different light intensities (80, 160, 240 and 320 µmol/m(2) s) and various mediums including control medium (CM), N/P rich medium (NPM), N rich medium (NM), and P rich medium (PM) were applied for cultivation of Chlorella sp. It was revealed that cultivation of Chlorella sp. in CM under the light intensity of 320 µmol/m(2) s led to a lipid content up to 30% enhancement, which was higher than the results of other cases. A rather high unsaturated fatty acid (UFA) content of 7.5% and unsaturated fatty acid/total fatty acid (UFA/TFA) ratio of 0.73 were obtained under 320 µmol/m(2) s in CM, indicating that the CM-320 system was applicable for the generation of UFA. Moreover, Chlorella sp. cultivated in PM under 320 µmol/m(2) s provided higher TFA content (7.3%), which was appropriate for biofuel production.