Exploring research trends and priorities of genus Melia

The genus Melia is known for its secondary metabolites and recently, this genus is being explored for its timber. There are vast differences among its species. For instance, Melia azedarach is reported to be invasive and while another species, M. dubia, has diverse utility with complex germination and regeneration characteristics. Researchers globally have been working on various aspects of this genus; In this study, using topic modelling and science mapping approach, we attempted to understand research facets on this genus. The literature corpus of the Web of Science database was explored using a single keyword-"Melia" which yielded 1523 publications (1946-2022) and after scrutiny metadata of 1263 publications were used in the study. Although nine individual species were cited in the publications, only three species are accepted viz., M. dubia, M. azedarach, and M. volkensii. This implies taxonomic uncertainty, with potential confusion in assigning scientific findings to particular species. Thus, a taxonomic relook on this genus is warranted for a better assessment of the economic utility in many countries. More importantly, our results indicate that the research interests have recently shifted from the secondary metabolite constituents towards growth, biomass, wood properties, germination, plantation, and green synthesis. The shift in research focus toward wood properties of Melia sp. can impact the wood demand-supply at a global scale owing to its fast growth and the possibility of cultivation over a wider geographical range.

Differential gene expression analysis reveals the fast-growth mechanisms in Melia dubia at different stand ages

BACKGROUND

Melia dubia Cav. is a fast-growing multipurpose tree suitable for agroforestry and has been widely cultivated for wood-based industries, particularly pulp and paper production. Despite its high economic value in India, there is a lack of information regarding the molecular mechanism driving its fast-growth. Therefore, this study aimed to elucidate the molecular mechanisms responsible for fast-growth by expression analysis of selective candidate genes.

METHODS AND RESULTS

Initially, growth traits were assessed, including tree height and diameter at breast height (DBH), across three different ages (one-year-old, two-year-old, and three-year-old) of M. dubia plantations. Tree volume based on tree height and DBH, was also calculated. The analysis of annual tree height increment revealed that the second-year plantation exhibited the higher increment, followed by first and third years. In contrast, DBH was maximum in third-year plantation, followed by the second and first years. Similarly, annual tree volume increment showed a similar trend with DBH that maximum in the third year, followed by second and first years. Furthermore, a differential gene expression analysis was performed using qRT-PCR on four genes such as Phloem Intercalated with Xylem (PXY), Clavata3/Embryo Surrounding Region-Related 41 (CLE41), 1-aminocyclopropane-1-carboxylic acid synthase (ACS-1) and Hemoglobin1 (Hb1) for downstream analysis. The relative gene expression showed up-regulation of CLE41, ACS-1, and Hb1 genes, while the PXY gene was downregulated across the tree ages. Interestingly, a positive association was observed between tree growth and the expression of the selected candidate genes.

CONCLUSION

Our results pave the way for further research on the regulatory mechanisms of genes involved in fast-growth and provide a basis for genetic improvement of Melia dubia.

Whole plant response of Pongamia pinnata to drought stress tolerance revealed by morpho-physiological, biochemical and transcriptome analysis

BACKGROUND

Pongamia is considered an important biofuel species worldwide. Drought stress in the early growth stages of Pongamia influences negatively on the germination and seedling development. Due to lack of cultivar stability under drought stress conditions, establishment of successful plantation in drought hit areas becomes a major problem. To address this issue, drought stress response of four Pongamia genotypes was studied at morphological, physio-chemical and transcriptome levels.

METHODS AND RESULTS

Drought stress was levied by limiting water for 15 days on three months old seedlings of four genotypes. A significant effect of water stress was observed on the traits considered. The genotype NRCP25 exhibited superior morpho-physiological, biochemical drought responses. Also, the genotype had higher root length, photosynthetic pigments, higher antioxidant enzymes and solute accumulation compared to other genotypes. In addition, transcript profiling of selected drought responsive candidate genes such as trehalose phosphate synthase 1 (TPS1), abscisic acid responsive elements-binding protein 2 (ABF2-2), heat shock protein 17 (HSP 17 kDa), tonoplast intrinsic protein 1 (TIP 1-2), zinc finger homeodomain protein 2 (ZFP 2), and xyloglucan endotransglucolase 13 (XET 13) showed only up-regulation in NRCP25. Further, the transcriptome responses are in line with key physio-chemical responses exhibited by NRCP25 for drought tolerance.

CONCLUSIONS

As of now, there are no systematic studies on Pongamia drought stress tolerance; therefore this study offers a comprehensive understanding of whole plant drought stress responsiveness of Pongamia. Moreover, the results support important putative trait indices with potential candidate genes for drought tolerance improvement of Pongamia.

Organic zinc and copper supplementation on antioxidant protective mechanism and their correlation with sperm functional characteristics in goats

Trace minerals feeding had significant effects on sperm production and fertility with better absorption and proper utilization within the body for optimum reproductive function. Several studies have shown that more influenced trace elements in the diets of animals are copper (Cu) and zinc (Zn). Bucks showing deficiency of this mineral might affect the quality of semen production which in turn would affect the fertility. This experiment was thus designed to test the effects of organic Cu and Zn supplementation on antioxidants enzyme activities and sperm functional attributes in fresh semen of bucks. Forty bucks (n = 40, Aged 5 months) were assigned to ten groups of four animals in each group, supplemented (for a period of 8 months) with different levels of organic Zn: 20 mg (T2), 40 mg (T3) and 60 mg (T4), organic Cu: 12.5 mg (T5), 25 mg (T6), 37.5 mg (T7) and combined organic Zn and Cu: 20 + 12.5 mg (T8), 40 + 25 mg (T9), 60 + 37.5 mg (T10), respectively, per kg dry matter and no additional mineral diet (control; T1). One hundred and sixty semen samples were collected through electro-ejaculator and analysed for sperm quantity, quality, acrosome intactness and plasma membrane integrity and correlated with the catalase, superoxide dismutase, glutathione peroxidase and glutathione reductase enzyme activities in seminal plasma. The results indicated organic Cu and zinc supplemented bucks produced more sperm cells, had higher sperm concentrations, maintained higher (p < .01) sperm livability, plasma membrane and acrosome integrities, more motility and velocity. The increased antioxidant enzyme activities, reduced oxidative stress and lowered lipid peroxidation were positively correlated (p < .05) with the sperm functional attributes. In conclusion, organic Cu and Zn supplement to male goats showed protective roles against oxidative damage and maintained better fresh semen characteristics.

Systemic therapy treatment patterns in patients with advanced non-small cell lung cancer (NSCLC): PIvOTAL study

The aim of this multinational retrospective cohort study, conducted at academic and community oncology centres, was to describe real‐world treatment patterns for patients with a confirmed diagnosis of advanced/metastatic (stage IIIB/IV) non‐small cell lung cancer (NSCLC) who initiated first‐line systemic therapy from January 2011 through June 2014. The study included 1265 patients in Italy, Spain, Germany, Australia, Korea, Taiwan and Brazil. The proportion of patients with squamous versus non‐squamous NSCLC was approximately 20% versus 75%, and associated patient demographic characteristics were similar in all countries, excepting race. Patients with squamous NSCLC were predominantly male and current/ex‐smokers. Biomarker tests were performed for the majority of patients with non‐squamous NSCLC, ranging from 54% (Brazil) to 91% in Taiwan, where, of those tested, 68% with non‐squamous NSCLC had positive epidermal growth factor receptor (EGFR)‐mutation status; in other countries the EGFR‐positive percentages ranged from 17% (Spain/Brazil) to 40% (Korea). Platinum‐based regimens were the most common first‐line therapy in all countries except Taiwan, where gefitinib was the most common first‐line agent. Median overall survival ranged from 9.3 months (Brazil) to 25.5 months (Taiwan). The diagnostic and treatment patterns recorded in this study were heterogeneous but largely in line with NSCLC guidelines during the study period.

Characterization of sprayed TiO2 on ITO substrates for solar cell applications

Titanium dioxide (TiO2) thin films had been deposited with various substrate temperatures by spray pyrolysis technique onto ITO substrates. All films exhibited polycrystalline nature with the preferred orientation along (101) plane. At the substrate temperature 450 °C, the film favored the formation of anatase phase. The higher substrate temperature (475 °C) favored the appearance of rutile structure. The SEM image of the film at substrate temperature (Ts=450 °C) showed high structural quality with the porous nature. The typical AFM image of TiO2 film deposited at the substrate temperature, 450 °C depicted the regular arrangement of fine closely packed tetragonal structured grains. The transmittance of the spectra exhibited above 85% with energy band gap of 3.6 eV. From the study of photoluminescence, the emission at 417 nm, 437 nm and with weak emission at 551 nm was observed, which confirmed the lesser defects in the samples. The electrical resistivity was found to be 6.856×10(1) Ω cm for the substrate temperature 450 °C. The efficiency of anatase TiO2 photoelectrode deposited at the substrate temperature 450 °C based cell was much higher than the efficiency of TiO2 photoelectrode deposited at the substrate temperature 475 °C based cell.

Physical properties of Zn doped TiO2 thin films with spray pyrolysis technique and its effects in antibacterial activity

Zinc doped Titanium dioxide (TiO2: Zn) thin films were deposited onto glass substrates by the spray pyrolysis technique with the substrate temperature 450°C. The structural, optical, photoluminescence (PL) properties and morphological studies were investigated for the films deposited with various doping concentration (0, 2, 4, 6 and 8at.%) of zinc. The results of X-ray diffraction (XRD) had shown the presence of anatase peak with a strong orientation along (101) plane at 8at.% of Zn-doped TiO2 film. Scanning electron microscopy (SEM) study showed the uniform distribution of grains with porous nature. Atomic force microscopy (AFM) observations indicated the tetragonal shape at 8at.% of Zn-doped TiO2 with the particle size and decrease in surface roughness. The emission at 398nm was observed at the 8at.% of Zn-doped TiO2 thin film. The carrier concentration and Hall mobility was increased with doping. The antibacterial activity was highly yielded for the Zn-doped TiO2 thin films.

Biochemical and hormonal variables in black and white women matched for age and weight

Weight and age may influence the levels of indexes of bone remodeling and the calciotropic hormones. In a study of interracial differences in these women, our black population was heavier than our white population. We therefore matched a subset of 96 black and 96 white women from our larger population for age and weight to determine whether a racial difference exists independent of the effects of weight and age. In addition, we were able to measure other indexes of bone remodeling (N-telopeptide of cross-linked collagen and pyridinoline cross-links), as well as hormones that may influence calcium metabolism (insulin-like growth factor-1 (IGF-1), insulin, calcitonin, and gastrin) in this subset. All indexes of bone remodeling were lower in black women. Black postmenopausal women had lower serum levels of calcidiol and higher parathyroid hormone (PTH) levels. The higher bone mass of black women is associated with lower bone remodeling in the presence of skeletal resistance to PTH. Serum IGF- 1, insulin, and calcitonin levels did not differ significantly between races. Serum gastrin levels were higher in black women. The higher levels of gastrin in black women should be investigated further for its possible effect on the absorption of calcium salts.