All members of the Arabidopsis DGAT and PDAT acyltransferase families operate during high and low temperatures.

The accumulation of triacylglycerol (TAG) in vegetative tissues is necessary to adapt to changing temperatures. It has been hypothesized that TAG accumulation is required as a storage location for maladaptive membrane lipids. The TAG acyltransferase family has five members (DIACYLGLYCEROL ACYLTRANSFERSE1/2/3 and PHOSPHOLIPID:DIACYLGLYCEROL ACYLTRANSFERASE1/2), and their individual roles during temperature challenges have either been described conflictingly or not at all. Therefore, we used Arabidopsis (Arabidopsis thaliana) loss of function mutants in each acyltransferase to investigate the effects of temperature challenge on TAG accumulation, plasma membrane integrity, and temperature tolerance. All mutants were tested under one high- and two low-temperature regimens, during which we quantified lipids, assessed temperature sensitivity, and measured plasma membrane electrolyte leakage. Our findings revealed reduced effectiveness in TAG production during at least one temperature regimen for all acyltransferase mutants compared to the wild type, resolved conflicting roles of pdat1 and dgat1 by demonstrating their distinct temperature-specific actions, and uncovered that plasma membrane integrity and TAG accumulation do not always coincide, suggesting a multifaceted role of TAG beyond its conventional lipid reservoir function during temperature stress.

Evaluation of potential anti-metastatic and antioxidative abilities of natural peptides derived from Tecoma stans (L.) Juss. ex Kunth in A549 cells.

Background: Tecoma stans (L.) Juss. ex Kunth is a well-known medicinal plant found in tropical and subtropical regions. It contains a broad range of bioactive compounds that exhibit many biological effects, including antidiabetic, antibacterial, and antioxidative activities. However, the effect of natural peptides from T. stans against cancer progression and free radical production is unknown. This study aims to evaluate the cytotoxic, anti-metastatic, and antioxidative activities of natural peptides from T. stans on A549 cells. Methods: The natural peptides were extracted from the flower of T. stans using the pressurized hot water extraction (PHWE) method, followed by size exclusion chromatography and solid-phase extraction-C18. The cytotoxic and anti-metastatic effects of natural peptides were evaluated using MTT and transwell chamber assays, respectively. The free radical scavenging activity of natural peptides was determined using ABTS, DPPH, and FRAP assays. The cells were pretreated with the IC50 dosage of natural peptides and stimulated with LPS before analyzing intracellular reactive oxygen species (ROS) and proteomics. Results: Natural peptides induced cell toxicity at a concentration of less than 1 ng/ml and markedly reduced cell motility of A549 cells. The cells had a migration rate of less than 10% and lost their invasion ability in the treatment condition. In addition, natural peptides showed free radical scavenging activity similar to standard antioxidants and significantly decreased intracellular ROS in the LPS-induced cells. Proteomic analysis revealed 1,604 differentially expressed proteins. The self-organizing tree algorithm (SOTA) clustered the protein abundances into eleven groups. The volcano plot revealed that the cancer-promoting proteins (NCBP2, AMD, MER34, ENC1, and COA4) were down-regulated, while the secretory glycoprotein (A1BG) and ROS-reducing protein (ASB6) were up-regulated in the treatment group. Conclusion: The anti-proliferative and anti-metastatic activities of natural peptides may be attributed to the suppression of several cancer-promoting proteins. In contrast, their antioxidative activity may result from the up-regulation of ROS-reducing protein. This finding suggests that natural peptides from T. stans are viable for being the new potential anti-cancer and antioxidative agents.

Population Structure of Nation-Wide Rice in Thailand.

BACKGROUND: Thailand is a country with large diversity in rice varieties due to its rich and diverse ecology. In this paper, 300 rice accessions from all across Thailand were sequenced to identify SNP variants allowing for the population structure to be explored. RESULTS: The result of inferred population structure from admixture and clustering analysis illustrated strong evidence of substructure in each geographical region. The results of phylogenetic tree, PCA analysis, and machine learning on population identifying SNPs also supported the inferred population structure. CONCLUSION: The population structure inferred in this study contains five subpopulations that tend to group individuals based on location. So, each subpopulation has unique genetic patterns, agronomic traits, as well as different environmental conditions. This study can serve as a reference point of the nation-wide population structure for supporting breeders and researchers who are interested in Thai rice.

Co-culture of males with late premolt to early postmolt female giant freshwater prawns, Macrobrachium rosenbergii resulted in greater abundances of insulin-like androgenic gland hormone and gonad maturation in male prawns as a result of olfactory receptors.

Insulin-like androgenic gland hormone (IAG) controls development of primary and secondary male sex-characteristics in decapod crustaceans. In male giant freshwater prawns, Macrobrachium rosenbergii, the IAG concentration correlates with male reproductive status and aggressiveness. When female prawns are co-cultured with males this can result in male size variations while this variation does not occur when males are cultured in monosex conditions. It was hypothesized that pheromone-like factors from female prawns may affect the abundance of IAG mRNA and protein in co-cultured males which would affect the pattern of sexual maturation of these males. In the present study, late premolt to postmolt females co-cultured with males for 7 days had a greater abundance of MrIAG mRNA transcript in all male phenotypes as well as for the gonad-somatic indexes (GSI). The abundance of MrIAG mRNA gradually increased from days 1 to 7 and using Western blot procedures MrIAG protein also increased in a similar pattern. Furthermore, with use of BrdU labeling, there was an increased cell proliferation in the spermatogenic zone of testicular tubules and in the spermatic duct epithelium during the 1 to 7 day co-culture period when there were increases in MrIAG mRNA and protein. In contrast, these effects were negated if short lateral antennules of males were ablated. Thus, results of the present study provide evidence that there might be female-molting factors which function as important regulators of androgenic gland function and gonadal maturation that were perceived by males via their short lateral antennules which are the olfactory organs.

The role of idioblasts in leaf water relations of tropical Rhododendron.

PREMISE OF THE STUDY: Although much is known about the anatomy of idioblasts, the relationship of leaf idioblasts to leaf physiology is poorly known. Our goal was to understand the relationship between idioblast abundance and leaf water relations. Tropical epiphytic and shrub Rhododendron species were the model system. METHODS: Leaf succulence and idioblast metrics of 61 plants representing 17 species were compared with stomatal and water relation metrics. Correlation, ANOVA, and regression were used to understand which water relation traits were best aligned with the proportion of the leaf occupied by idioblasts for epiphytic and shrub species. KEY RESULTS: Idioblast volume per leaf area varied from 1.4-9.5 mm3·cm-2 among accessions, and an index of stomatal area per leaf area varied from 0.08-3.3. Succulence, stomatal, and water relation metrics varied significantly among species. Total idioblast volume was negatively correlated with leaf succulence metrics, and positively correlated with relative water content at the turgor loss point. Idioblasts were better related to capacitance in thin leaves. All idioblast metrics were significantly greater in epiphytic species. CONCLUSIONS: Leaf idioblasts can have a significant effect on leaf-lamina water relations. Idioblasts likely function as a water buffering system for thin leaves in tropical Rhododendron species. The association of idioblast prominence with leaf water buffering is greatest for epiphytic species with thin leaves. Thus, the proliferation of leaf idioblasts may have been an important innovation for Rhododendron species diversification into tropical epiphytic habitats.