Exploring the awareness, attitude, and inclination of healthcare students towards interprofessional education: A cross-sectional study in Saudi Arabia.

Background: Interprofessional education (IPE) is acknowledged to enhance understanding between professionals and to facilitate learning. Healthcare professionals may be better equipped to accept and esteem other healthcare professionals, if interprofessional education is incorporated into undergraduate curricula. The management of challenging patient issues may also significantly benefit from this. As a result, the current study examined interprofessional education in their institutions and students' knowledge of and attitudes toward it. Methodology: We conducted a cross-sectional questionnaire-based study among students from a university in the southwest of Saudi Arabia, who were enrolled in courses in medical, pharmacy, nursing, dentistry, allied health, and public health. Following validation, the questionnaire included six questions to probe their knowledge, ten questions to gauge their attitude, and eleven questions to inquire about the growth and use of IPE in their institutions. Multiple regression and the Kruskal-Wallis test were used to examine the data. Results: The survey involved 600 students, and 66.8% of the respondents were male. Less than one-third of students studying medicine replied to the survey, while students in the public health department had the lowest response rate. Compared to students in other programs, pharmacy students achieved a higher mean attitude score toward IPE (P < 0.001). Additionally, nursing and pharmacy students' mean IPE awareness scores were higher than those of medical students (P < 0.001). However, all program participants firmly agreed that integrating IPE into the curriculum was a good idea. Conclusions: The study found that students of a few programs had awareness and a positive attitude toward interprofessional education. Nonetheless, all of them favored its inclusion in their curriculum. They also stressed the need to educate teaching faculty on interprofessional education, to develop skilled facilitators within their institutions.

Detection of chikungunya virus in the Southern region, Saudi Arabia.

BACKGROUND AND AIM: Despite the fact that the chikungunya viral infection is a neglected disease, complications such as hemorrhagic fever, arthritis, and lymphopenia remain a health concern. The aim of this study was to determine the prevalence of the chikungunya virus in the Southern Region, Saudi Arabia. Enzyme immunoassay and polymerase chain reaction have been compared between samples. MATERIALS AND METHODS: Forty samples from two southern hospitals in Saudi Arabia were collected between December 2019 and February 2020 and screened for chikungunya virus IgG antibodies and for viral RNA. Selection criteria were based on hematological parameters and rheumatological profiles such as rheumatoid factor, c-reactive protein, anti-nuclear antibody, and anti-cyclic citrullinated peptide (anti-CCP) of out-patients. RESULTS: One confirmed case of chikungunya virus was detected using the ELISA test. However, no viral RNA was detected in any of the samples. This suggests that the virus is cleared rapidly in patients. CONCLUSION: Chikungunya is a neglected viral disease in Saudi Arabia. Future work should focus on detailed investigation of this viral infection and its vectors.

Genome-wide identification and expression analysis of detoxification efflux carriers (DTX) genes family under abiotic stresses in flax.

The detoxification efflux carriers (DTX)/multidrug and toxic compound extrusion (MATE) transporters encompass an ancient gene family of secondary transporters involved in the process of plant detoxification. A genome-wide analysis of these transporters was carried out in order to better understand the transport of secondary metabolites in flaxseed genome (Linum usitassimum). A total of 73 genes coding for DTX/MATE transporters were identified. Gene structure, protein domain and motif organization were found to be notably conserved over the distinct phylogenetic groups, showing the evolutionary significant role of each class. Gene ontology (GO) annotation revealed a link to transporter activities, response to stimulus and localizations. The presence of various hormone and stress-responsive cis-regulatory elements in promoter regions could be directly correlated with the alteration of their transcripts. Tertiary structure showed conservation for pore size and constrains in the pore, which indicate their involvement in the exclusion of toxic substances from the cell. MicroRNA target analysis revealed that LuDTXs genes were targeted by different classes of miRNA families. Twelve LuDTX genes were chosen for further quantitative real-time polymerase chain reaction analysis in response to cold, salinity and cadmium stress at 0, 6, 12 and 24 hours after treatment. Altogether, the identified members of the DTX gene family, their expression profile, phylogenetic and miRNAs analysis might provide opportunities for future functional validation of this important gene family in flax.

Comparative study of the genetic basis of nitrogen use efficiency in wild and cultivated barley.

To curb the increasing demand for nitrogenous fertilizers, it is imperative to develop new cultivars with comparatively greater nitrogen use efficiency (NUE). Nonetheless, so far very meager information is available concerning the variances among barley (Hordeum vulgare L.) varieties for their response to nitrogen deprivation. The current study was carried out to explore the potential of barley genotypes for higher NUE. A hydroponic experiment was conducted at seedling stage to compare the performance of four barley genotypes, ZD9 and XZ149 (with higher NUE) and HXRL and XZ56 (with lower NUE) in response to low (0.1 mM) and normal nitrogen (2 mM) levels. Under low N, all the genotypes expressed less number of tillers, decreased soluble proteins, chlorophyll and N concentrations in both roots and shoots, in comparison with normal N supply. However, significant differences were found among the genotypes. The genotypes with high NUE (ZD9 and XZ149) showed higher N concentration, increased number of tillers, improved chlorophyll and soluble proteins in both roots and shoots as compared to the inefficient ones (HXRL and XZ56). Furthermore, nitrate transporter gene (NRT2.1) showed higher expression under low N, both in roots and leaves of N efficient genotypes, as compared to the N inefficient ones. However, N assimilatory genes (GS1 and GS2) showed higher expression under normal and low N level, in leaves and roots respectively. The outcome of the study revealed that genotypes with higher NUE (ZD9 and XZ149) performed better under reduced N supply, and may require relatively less N fertilizer for normal growth and development, as compared to those with lower NUE. The study also revealed a time-specific expression pattern of studied genes, indicating the duration of low N stress. The current study suggested that future work must involve the time course as a key factor while studying expression patterns of these genes to better understand the genetic basis of low-N tolerance.

Interaction of palladium inorganic salt and organic complex with glutathione content of liver homogenate.

Glutathione is an essential antioxidant of living organism that provides a primary protection against metals toxicity. A significant amount of glutathione is present in blood erythrocytes, plasma and liver hepatocytes to protect them from oxidative damage from both external and internal oxidants. Metalo-element palladium has numerous pharmacological, clinical and toxicological compensations, like palladium is used as anti-viral, anti-bacterial, neuro-protective and anti-tumor agent. However studies have also indicated some mild to serious toxic effects of palladium metallo-elements. In the presence study the interaction of palladium inorganic salt and organic complex with glutathione (GSH) content of liver homogenate was examined spectro-photometrically. 20% (w/v) liver homogenate was prepared of the collected liver of rabbit in 5% TCA (tri-chloro-acetic acid) solution and 1mm EDTA, using a potter-eveljhem homogenizer with motor driven Teflon pestle. The GSH content quantification was carried out by Elman's method. Our finding showed that there was a depletion of GSH content by both palladium inorganic salts and organic complexes, concentrations wise as well as with time elapse as level of GSH content decrease from (43.6% to 72.62%) with Palladium Nitrate and from (24.09 to 59.5%) with Bis-benzonitrile Palladium II Chloride as compared to control, and further dropped with time incubation from 0-90 minutes from (49.7 to 87.1%), with Palladium Nitrate and from (29.3% to 67.6%) respectively. The result showed that the effect of both inorganic salt of palladium was more enhanced as compare to its organic complex. It was suggested from our finding that the depletion in the glutathione content of liver homogenate may be due to oxidation of glutathione or due to glutathione metal abduct formation by both inorganic salt and organic complex of palladium. This study in situ is a model of in vivo.

Comprehensive genomic analysis of the CNGC gene family in Brassica oleracea: novel insights into synteny, structures, and transcript profiles.

BACKGROUND: The cyclic nucleotide-gated ion channel (CNGC) family affects the uptake of cations, growth, pathogen defence, and thermotolerance in plants. However, the systematic identification, origin and function of this gene family has not been performed in Brassica oleracea, an important vegetable crop and genomic model organism. RESULTS: In present study, we identified 26 CNGC genes in B. oleracea genome, which are non-randomly localized on eight chromosomes, and classified into four major (I-IV) and two sub-groups (i.e., IV-a and IV-b). The BoCNGC family is asymmetrically fractioned into the following three sub-genomes: least fractionated (14 genes), most fractionated-I (10), and most fractionated-II (2). The syntenic map of BoCNGC genes exhibited strong relationships with the model Arabidopsis thaliana and B. rapa CNGC genes and provided markers for defining the regions of conserved synteny among the three genomes. Both whole-genome triplication along with segmental and tandem duplications contributed to the expansion of this gene family. We predicted the characteristics of BoCNGCs regarding exon-intron organisations, motif compositions and post-translational modifications, which diversified their structures and functions. Using orthologous Arabidopsis CNGCs as a reference, we found that most CNGCs were associated with various protein-protein interaction networks involving CNGCs and other signalling and stress related proteins. We revealed that five microRNAs (i.e., bol-miR5021, bol-miR838d, bol-miR414b, bol-miR4234, and bol-miR_new2) have target sites in nine BoCNGC genes. The BoCNGC genes were differentially expressed in seven B. oleracea tissues including leaf, stem, callus, silique, bud, root and flower. The transcript abundance levels quantified by qRT-PCR assays revealed that BoCNGC genes from phylogenetic Groups I and IV were particularly sensitive to cold stress and infections with bacterial pathogen Xanthomonas campestris pv. campestris, suggesting their importance in abiotic and biotic stress responses. CONCLUSION: Our comprehensive genome-wide analysis represents a rich data resource for studying new plant gene families. Our data may also be useful for breeding new B. oleracea cultivars with improved productivity, quality, and stress resistance.

The role of Glutathione, Cysteine and D-Penicillamine in exchanging Palladium and Vanadium metals from albumin metal complex.

Thiol groups are extensively present across biological systems being found in range of small molecules (e.g. Glutathione, Homo-cysteine) and proteins (e.g. albumin, haemo-globin). Albumin is considered to be a major thiol containing protein present in circulating Plasma. Albumin contains a single thiolate group located at cysteine-34(cys-34) at its active site. Albumin also binds a wide variety of metals and metals complexes at various sites around the protein. Usually heavy metals are preferentially attached with the thiol group of albumin. The binding of heavy metals at cys-34 provides a mechanism by which the residence time of potentially toxic species in the body can be increased. In this research we have assessed the oxidative modification of and metal binding capacity of cys-34 with heavy metals Palladium and Vanadium to investigate the ease with which it is possible to effect disulfide-thiol exchange at this sites/or remove a metal bound at this position. Both the metals were treated with albumin and then the albumin metals (Pd and V) complexes were treated with small thoil molecules like Glutathione, Cysteine and D-Penicillamine. Our finding showed that the albumin thiol group retained the metals with itself by forming some strong bonding with the Thiols group, it is concluded from this finding that if by chance both the metals enter the living system; strongly disturb the chemistry and physiological function of this bio-molecule.

TRANSPARENT TESTA8 Inhibits Seed Fatty Acid Accumulation by Targeting Several Seed Development Regulators in Arabidopsis.

Fatty acids (FAs) and FA-derived complex lipids play important roles in plant growth and vegetative development and are a class of prominent metabolites stored in mature seeds. The factors and regulatory networks that control FA accumulation in plant seeds remain largely unknown. The role of TRANSPARENT TESTA8 (TT8) in the regulation of flavonoid biosynthesis and the formation of seed coat color is extensively studied; however, its function in affecting seed FA biosynthesis is poorly understood. In this article, we show that Arabidopsis (Arabidopsis thaliana) TT8 acts maternally to affect seed FA biosynthesis and inhibits seed FA accumulation by down-regulating a group of genes either critical to embryonic development or important in the FA biosynthesis pathway. Moreover, the tt8 mutation resulted in reduced deposition of protein in seeds during maturation. Posttranslational activation of a TT8-GLUCOCORTICOID RECEPTOR fusion protein and chromatin immunoprecipitation assays demonstrated that TT8 represses the activities of LEAFY COTYLEDON1, LEAFY COTYLEDON2, and FUSCA3, the critical transcriptional factors important for seed development, as well as CYTIDINEDIPHOSPHATE DIACYLGLYCEROL SYNTHASE2, which mediates glycerolipid biosynthesis. These results help us to understand the entire function of TT8 and increase our knowledge of the complicated networks regulating the formation of FA-derived complex lipids in plant seeds.

Risk of disordered eating attitudes among adolescents in seven Arab countries by gender and obesity: a cross-cultural study.

The objectives were to discover the prevalence of disordered eating attitudes (EAs) among adolescent males and females, and the association of obesity with EA in seven Arab countries. A multistage stratified sampling technique was used to select secondary students aged 15-18 years from cities in Algeria, Jordan, Kuwait, Libya, Palestine, Syria and Sharijah Emirate (United Arab Emirates). The total sample was 4698 (2240 males and 2458 females). The Eating Attitudes Test (EAT-26) was used to measure those at risk of disordered EA. Obesity was calculated according to the International Obesity Taskforce criteria. Participants were grouped into two categories, non-obese and obese (overweight and obese). The risk of disordered EA was twice as high among females as in males in Jordan, Libya, Palestine and Syria. Kuwaiti adolescents (males and females) showed higher prevalence of disordered EA than their counterparts in other countries. The risk of disordered EA among obese adolescents was two to three times higher than that of non-obese adolescents, in both genders. Excepting Kuwaiti females and Palestinian males. The association of obesity with disordered EA was statistically significant. This study highlighted the magnitude of the risk of disordered eating attitudes among both male and female adolescents in Arab countries and identified the need for programmes to prevent and control these disorders in the Arab region.

Perceived barriers to healthy eating and physical activity among adolescents in seven Arab countries: a cross-cultural study.

OBJECTIVE: To highlight the perceived personal, social, and environmental barriers to healthy eating and physical activity among Arab adolescents. METHOD: A multistage stratified sampling method was used to select 4698 students aged 15-18 years (2240 males and 2458 females) from public schools. Seven Arab counties were included in the study, namely, Algeria, Jordan, Kuwait, Libya, Palestine, Syria, and the United Arab Emirates. Self-reported questionnaire was used to list the barriers to healthy eating and physical activity facing these adolescents. RESULTS: It was found that lack of information on healthy eating, lack of motivation to eat a healthy diet, and not having time to prepare or eat healthy food were the main barriers to healthy eating among both genders. For physical activity, the main barriers selected were lack of motivation to do physical activity, less support from teachers, and lack of time to do physical activity. In general, females faced more barriers to physical activity than males in all countries included. There were significant differences between males and females within each country and among countries for most barriers. CONCLUSION: Intervention programmes to combat obesity and other chronic noncommunicable diseases in the Arab world should include solutions to overcome the barriers to weight maintenance, particularly the sociocultural barriers to practising physical activity.

CRISPR-mediated technology for seed oil improvement in rapeseed: Challenges and future perspectives.

Rapeseed not only provide considerable amount of edible oil with high nutritional properties but can also be used as a raw material for biofuel production in many industries. It is therefore in high demand to bring genetic changes in order to fulfill the need of human and of industries. Though traditional breeding techniques such as hybridization and mutagenesis remained the top methods for long time to create improved varieties in oilseed rape. Clustered regularly interspaced short palindromic repeats (CRISPR) is becoming one of the most valuable gene editing technologies that allow precise genome engineering, and open new ways for research in plant functional genomics. Though CRISPR has been used in many other crops for genetic improvement it is expected to be an effective tool for genome editing and molecular design in oilseed rape for seed oil improvement. This mini review will discuss and summarize the past and ongoing research and development in rapeseed in terms of seed oil improvement and fatty acid composition using CRISPR technology. In addition, the factors that hinder the efficiency of this tool and how to eliminate those factors will be briefly summarized. The improvement of CRISPR technology for getting better results in oilseed rape will also be considered here. This minireview will open new windows for researchers in Brassica napus oil improvement research and genetic improvement using CRISPR technology.

Salicylic acid-mitigates abiotic stress tolerance via altering defense mechanisms in Brassica napus (L.).

Under the changing climate due to global warming, various abiotic stresses including drought (D) and salinity (S) are expected to further trigger their devastating effects on the already vulnerable crop production systems. This experiment was designed to unravel and quantify the potential role of exogenous application of salicylic acid (SA) in mitigating both D and S stresses and their combination (D+S), with three replications using CRD (Completely Randomized Design). The obtained results of the current study demonstrated significant effects of all three types of stresses (D, S, and D+S) on various parameters in Brassica napus plants. Quantifying these parameters provides a more informative and precise understanding of the findings. Current results revealed that all three stress types (D, S, and D+S) resulted in a reduction in leaf area (13.65 to 21.87%), chlorophyll levels (30 to 50%), gaseous exchange rate (30 to 54%) and the concentration of mineral ions compared to non-stressed plants. However, application of SA helped in mitigating these stresses by ameliorating the negative effects of these stresses. Moreover, Malondialdehyde (MDA) contents, an indicator of lipid per-oxidation and oxidative stress, the levels of antioxidants, proline content, an osmolyte associated with stress tolerance, and sugar content in the leaves were elevated in response to all stress conditions. In addition, the ultra-structures within the leaves were negatively affected by the stresses, while an application of SA considerably minimized the deterioration of these structures thus providing protection to the brassica plants against the stresses. In a nutshell, the findings of this study suggest that SA application in S, D and S+ D stresses provides evasion to the plants by improving different physiological and growth indices. The application of Salicylic Acid (SA) mitigated the negative effects of the stresses on all the above parameters, reducing MDA contents (47%), antioxidants (11 to 20%), proline (28%), sugar contents (20.50%), and minimizing the deterioration of ultra-structures. The findings emphasize the potential mitigatory role of SA in mitigating D and S stresses and highlight the need for further research to understand the underlying mechanisms in detail and explore its practical application in farming practices.

Knowledge, Attitudes, and Practices of the Population in Jazan Region, Saudi Arabia Regarding Dengue Fever and Its Prevention Measures: A Community-Based Cross-Sectional Study.

In previous studies, there was an apparent lack of health education about dengue fever (DF) among the Saudi population. Therefore, we conducted this study to assess the knowledge, attitude, and practices (KAP) about dengue fever among the Jazan region population, which is one of the most prevalent diseases in the region in Saudi Arabia (KSA). This was a cross-sectional and community-based study. The adult population was divided into governorates according to the regions that were close to each other, and then a convenient stratum was selected from each region. Next, random sampling was applied. Data were collected using a self-administered questionnaire. Exclusion criteria were young people (<18 years old) and health workers. Data analysis was performed using descriptive statistics, the Pearson's correlation coefficient, and multiple linear regression. Of the 392 participants in this cross-sectional study, 59.18% were male, 76.28% were aged 18-35 years, 72.96% had a university degree, and 63% had a monthly income of less than SAR 5000 (USD1 = 3.76). The scores (mean ± SD) for KAP regarding DF among the responders were 22.77 ± 7.9, 22.68 ± 7.24, and 25.62 ± 9.4, respectively. KAP constructs were positively correlated according to the Pearson's coefficient. In multiple linear regression analysis, males were favorably and substantially linked with attitude score (ß = 2.76, p = 0.001) and negatively associated with practice score (ß = -2.45, p = 0.023). No-degree participants scored lower on knowledge (ß = -2.78, p = 0.003). There is potential for more research in Saudi Arabia to increase the generalizability to reduce the impact of dengue epidemics.

Indigenous Tocopherol Improves Tolerance of Oilseed Rape to Cadmium Stress.

Two oilseed rape genotypes (Jiu-Er-13XI and Zheyou-50), differing in seed oil content, were subjected to cadmium (Cd) stress in hydroponic experiment. Genotypic differences were observed in terms of tolerance to Cd exposure. Cd treatment negatively affected both genotypes, but the effects were more devastating in Jiu-Er-13XI (low seed oil content) than in Zheyou-50 (high seed oil content). Jiu-Er-13XI accumulated more reactive oxygen species (ROS), which destroyed chloroplast structure and decreased photosynthetic pigments, than Zheyou-50. Total fatty acids, especially 18:2 and 18:3, severely decreased as suggested by increase in MDA content. Roots and shoots of Jiu-Er-13XI plants accumulated more Cd content, while less amount of tocopherol (Toc) was observed under Cd stress, than Zheyou-50. Conversely, Zheyou-50 was less affected by Cd stress than its counterpart. It accumulated comparatively less amount of Cd in roots and shoots, along with reduced accumulation of malondialdehyde (MDA) and ROS under Cd stress, than Jiu-Er-13XI. Further, the level of Toc, especially α-Tocopherol, was much higher in Zheyou-50 than in Jiu-Er-13XI, which was also supported by high expression of Toc biosynthesis genes in Zheyou-50 during early hours. Toc not only restricted the absorption of Cd by roots and its translocation to shoot but also scavenged the ROS generated during oxidative stresses. The low level of MDA shows that polyunsaturated fatty acids in chloroplast membranes remained intact. In the present study the tolerance of Zheyou-50 to Cd stress, over Jiu-Er-13XI, is attributed to the activities of Toc. This study shows that plants with high seed oil content are tolerant to Cd stress due to high production of Toc.

Calmodulin-binding transcription activator (CAMTA) genes family: Genome-wide survey and phylogenetic analysis in flax (Linum usitatissimum).

Flax (Linum usitatissimum) is a member of family linaceae with annual growth habit. It is included among those crops which were domesticated very early and has been used in development related studies as a model plant. In plants, Calmodulin-binding transcription activators (CAMTAs) comprise a unique set of Calmodulin-binding proteins. To elucidate the transport mechanism of secondary metabolites in flax, a genome-based study on these transporters was performed. The current investigation identified nine CAMTAs proteins, classified into three categories during phylogenetic analysis. Each group had significant evolutionary role as illustrated by the conservation of gene structures, protein domains and motif organizations over the distinctive phylogenetic classes. GO annotation suggested a link to sequence-specific DNA and protein binding, response to low temperature and transcription regulation by RNA polymerase II. The existence of different hormonal and stress responsive cis-regulatory elements in promotor region may directly correlate with the variation of their transcripts. MicroRNA target analysis revealed that various groups of miRNA families targeted the LuCAMTAs genes. Identification of CAMTA genes, miRNA studies and phylogenetic analysis may open avenues to uncover the underlying functional mechanism of this important family of genes in flax.

Prevalence of Dental Caries and Periodontal Status among Down's Syndrome Population in Riyadh City.

AIM: Aim of the present study was to evaluate the prevalence of dental caries and periodontal status among Down's syndrome population in Riyadh City. MATERIALS AND METHODS: A total of 81 male Down's syndrome subjects were examined in this study. All subjects were recruited from the Saudi Center for Down Syndrome, Riyadh. Clinical examination was carried out by a single precalibrated examiner. Dental caries experience was counted according to the DMFT (decayed, missing, and filled teeth) indexes. Periodontal status was evaluated by using plaque and gingival indexes. Statistical analysis was performed using SPSS 19 version. Consequently, Pearson chi-square test and Fisher exact test was used to calculate p-value for parametric variables. RESULTS: In this study 11.1% of the subjects were not having any decayed teeth, 39.5% were not having any missing teeth, and 55.6% were not having any filled teeth. In plaque index, maximum number of subjects in all the age group were in the fair group, and there was a highly significant (P value <0.001) association between the age group and the plaque index groups. In gingival index, maximum number of subjects in all the age group was in the poor group. No significant (P value = 0.697) association between the age group and the gingival index groups was found. CONCLUSION: The present study concluded that the prevalence of dental caries was high and periodontal status of Down's syndrome subjects was poor.

Role of jasmonic acid in improving tolerance of rapeseed (Brassica napus L.) to Cd toxicity.

The well-known detrimental effects of cadmium (Cd) on plants are chloroplast destruction, photosynthetic pigment inhibition, imbalance of essential plant nutrients, and membrane damage. Jasmonic acid (JA) is an alleviator against different stresses such as salinity and drought. However, the functional attributes of JA in plants such as the interactive effects of JA application and Cd on rapeseed in response to heavy metal stress remain unclear. JA at 50 µmol/L was observed in literature to have senescence effects in plants. In the present study, 25 µmol/L JA is observed to be a "stress ameliorating molecule" by improving the tolerance of rapeseed plants to Cd toxicity. JA reduces the Cd uptake in the leaves, thereby reducing membrane damage and malondialdehyde content and increasing the essential nutrient uptake. Furthermore, JA shields the chloroplast against the damaging effects of Cd, thereby increasing gas exchange and photosynthetic pigments. Moreover, JA modulates the antioxidant enzyme activity to strengthen the internal defense system. Our results demonstrate the function of JA in alleviating Cd toxicity and its underlying mechanism. Moreover, JA attenuates the damage of Cd to plants. This study enriches our knowledge regarding the use of and protection provided by JA in Cd stress.

Removal of DELLA repression promotes leaf senescence in Arabidopsis.

Leaf senescence is an integrated response of leaf cells to developmental age and various internal and environmental signals. However, the role of gibberellins (GA) in leaf senescence is not clear. In the current study, we investigated the effect of DELLA on leaf senescence. Compared with the wild type (WT), leaf senescence occurred earlier in the mutant ga1-3 gai-t6 rga-t2 rgl1-1 rgl2-1 (abbreviated as Q-DELLA/ga1-3) whose DELLA repression was removed, whereas leaf senescence was retarded in the mutant ga1-3 whose GA biosynthesis was blocked and whose DELLA proteins accumulated abnormally. During leaf senescence, SAG12 and SAG29 were upregulated in Q-DELLA/ga1-3 and downregulated in ga1-3 plants. The Q-DELLA/ga1-3 senescent leaves contained more sugar but less chlorophyll and fatty acids (FAs) than those of ga1-3 and WT. Both absolute and relative contents of C18:3 in Q-DELLA/ga1-3 senescent leaves were lower compared with those of the WT and ga1-3 leaves. The genes regulating FA ß-oxidation in Q-DELLA/ga1-3, such as KAT2, LACS6, LACS7, ACX1, ACX2 and MAP2, were significantly upregulated. The removal of DELLA repression highly upregulated certain genes on various hormone pathways, suggesting that GA signaling acts upstream of the jasmonic acid, salicylic acid, and ethylene pathways in regulating leaf senescence.

Response of seed tocopherols in oilseed rape to nitrogen fertilizer sources and application rates.

Tocopherols (Tocs) are vital scavengers of reactive oxygen species (ROS) and important seed oil quality indicators. Nitrogen (N) is one of the most important fertilizers in promoting biomass and grain yield in crop production. However, the effect of different sources and application rates of N on seed Toc contents in oilseed rape is poorly understood. In this study, pot trials were conducted to evaluate the effect of two sources of N fertilizer (urea and ammonium nitrate). Each source was applied to five oilseed rape genotypes (Zheshuang 72, Jiu-Er-1358, Zheshuang 758, Shiralee, and Pakola) at three different application rates (0.41 g/pot (N1), 0.81 g/pot (N2), and 1.20 g/pot (N3)). Results indicated that urea increased α-, γ-, and total Toc (T-Toc) more than did ammonium nitrate. N3 was proven as the most efficient application rate, which yielded high contents of γ-Toc and T-Toc. Highly significant correlations were observed between Toc isomers, T-Toc, and α-/γ-Toc ratio. These results clearly demonstrate that N sources and application rates significantly affect seed Toc contents in oilseed rape.

Correlations between tocopherol and fatty acid components in germplasm collections of Brassica oilseeds.

To date, little is known about the correlations among the tocopherol (T) and fatty acid (FA) components in rapeseed oils. In the current study, a germplasm collection of landraces from the species Brassica juncea , Brassica rapa , and Brassica napus and a collection of low erucic acid (EA) breeding lines from B. napus were analyzed for FA and T contents. In the groups comprising landraces, the most notable correlation was the significantly positive one between α-T and the sum of C18:1 and C18:2, whereas neither positive correlations were found between α-T and C18:3 nor were positive correlations observed between α-T and very long chain FAs (VLCFA). Hardly any association between γ-T and FA components was observed, indicating the possible function of α-T beyond its antioxidant property. The complexity of correlation between T and FA components in Brassica oils may arise from the role of α-T in the FA metabolism of endoplasmic reticulum (ER).