Understanding the nature of blast resistance in combined bacterial leaf blight and blast gene pyramided lines of rice variety tellahamsa.

BACKGROUND: Rice blast and bacterial leaf blight (BLB) are the most limiting factors for rice production in the world which cause yield losses typically ranging from 20 to 30% and can be as high as 50% in some areas of Asia especially India under severe infection conditions. METHODS AND RESULTS: An improved line of Tellahamsa, TH-625-491 having two BLB resistance genes (xa13 and Xa21) and two blast resistance genes (Pi54 and Pi1) with 95% Tellahamsa genome was used in the present study. TH-625-491 was validated for all four target genes and was used for backcrossing with Tellahamsa. Seventeen IBC1F1 plants heterozygous for all four target genes, 19 IBC1F2 plants homozygous for four, three and two gene combinations and 19 IBC1F2:3 plants also homozygous for four, three and two gene combinations were observed. Among seventeen IBC1F1 plants, IBC1F1-62 plant recorded highest recurrent parent genome (97.5%) covering 75 polymorphic markers. Out of the total of 920 IBC1F2 plants screened, 19 homozygous plants were homozygous for four, three and two target genes along with bacterial blight resistance. Background analysis was done in all 19 homozygous IBC1F2 plants possessing BLB resistance (possessing xa13, Xa21, Pi54 and Pi1 in different combinations) with five parental polymorphic SSR markers. IBC1F2-62-515 recovered 98.5% recurrent parent genome. The four, three and two gene pyramided lines of Tellahamsa exhibited varying resistance to blast. CONCLUSIONS: Results show that there might be presence of antagonistic effect between bacterial blight and blast resistance genes since the lines with Pi54 and Pi1 combination are showing better resistance than the combinations with both bacterial blight and blast resistance genes.

Exploration of bioactive compounds from Olea dioica in Western Ghats of Karnataka using GC-MS.

Bioactive compounds in plants are essential for the formation of novel chemotherapeutic drugs, which have been used in Ayurveda to treat a variety of illnesses. Indian medicinal herbs have been used for thousands of years to treat a variety of illnesses, such as fever, cancer, snake bites, rheumatism, skin problems, and neurodegenerative diseases. GC-MS was used to locate and categorize bioactive components in Olea dioica leaves. The results showed that presence of octanoic acid, methyl ester, decanoic acid, methyl ester, desulphosinigrin, l-gala-l-ido-octose, methyl tetradecanoate, Tetradecanoic acid, 6-benzoxazolesulfonamide, N-(2-hydroxyethyl)-2-methyl-, 10-chloro-5-methoxy-5H-dibenzo[a,d][7]annulene, pentadecanoic acid, oleic acid, n-hexadecanoic acid, hexanedioic acid, dioctyl ester, and squalene. The methanol extract of Olea dioica was effective against a wide spectrum of pathogenic bacteria at four different concentrations, with the highest activity against Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus, Xanthomonas campestris, and Salmonella typhimurium. It also showed moderate activity against Agrobacterium tumefaciens, Pseudomonas aeruginosa, Streptomyces pneumonia, and Pseudomonas syringae. The pharmacological properties of O. dioica, as well as their variety and comprehensive phytochemistry, could be exploited as a potent antimicrobial agent for future therapeutics.

Effects of dietary wheat supplementation levels on growth performance, rumen bacterial community and fermentation parameters in Chinese Tibetan Sheep.

The objective of this study was to evaluate various wheat supplementation levels on rumen microbiota and fermentation parameter in Tibetan sheep. A total of ninety ram with an average 12.37 ± 0.92 kg at the age of 2 months were randomly allocated to three treatments: 0% wheat diet (CW, N = 30), 10% wheat diet (LW, N = 30), and 15% wheat diet (HW, N = 30) on a dry matter basis. The experiment was conducted over a period of 127 days, including 7 days of adaption to the diets. Our results showed that sheep fed 10% wheat exhibited optimal average daily gain and feed gain ratio compared with HW group (p < 0.05). The serum alkaline phosphatase concentration was the lowest when fed the 10% wheat diet (p < 0.05), whereas serum aspartate aminotransferase concentration was the highest (p < 0.05). Both acetate and propionate increased with increase in dietary wheat ratio (p < 0.05), while a greater decrease in concentrations of NH3 -N was observed (p < 0.05). In rumen fluid, 3413 OTUs were obtained with 97% consistency. Phylum Firmicutes was the predominant bacteria and accounted for 49.04%. The CW groups supported significantly increased the abundance of Bacteroidetes (p < 0.05), as compared with the HW group. The abundance of Bacteroidales_UCG-001, Ruminococcus, and Mitsuokella possessed a higher relative abundance in HW group (p < 0.05). No differences in the bacterial community and fermentation parameters were observed between the sheep fed 0% and 10% wheat (p > 0.05). Ruminal bacterial community structure was significantly correlated with isobutyrite (r2 = 0.4878, p = 0.035) and valerate (r2 = 0.4878, p = 0.013). In conclusion, supplementation of 10% wheat in diet promoted the average daily gain and never altered microbial community structure and fermentation pattern, which can be effectively replace partial corn in Chinese Tibetan Sheep.

Promising bioactive metabolites of mangrove inhabitant Streptomyces tauricus and prostate cancer PC3 cell inhibition by antimicrobial peptides.

Streptomyces is a group of microbes known for antibiotic production and has contributed to more than 70% of present commercially available antibiotics. These antibiotics are important in the management, protection, and treatment of chronic illnesses. In the present study, the isolated S. tauricus strain from mangrove soil in Mangalore, India (GenBank accession number: MW785875) was subjected for differential cultural characterization, phenotype involving brown pigmentation, filamentous mycelia, and ash-colored spore production was observed using field emission scanning electron microscopy (FESEM) analysis revealing filamentous mycelia possessing a straight spore chain. Spores were visualized as elongated, rod-shaped, smooth surfaces with curved edges. After optimized growth conditions for S. tauricus on starch-casein agar medium, the GC/MS analysis of S. tauricus intracellular extract detected bioactive compounds reported for pharmacological applications. Analyzed using the NIST library, most of the bioactive compounds identified in intracellular extract had molecular weights of less than 1 kDa. On the PC3 cell line, the Sephadex G-10 partially purified eluted peak protein fraction demonstrated significant anticancer activity. The LCMS analysis revealed the presence of Tryprostatin B, Fumonisin B1, Microcystin LR, and Surfactin C with molecular weights below 1 kDa. This study found that small molecular weight microbial compounds are more effective in a variety of biological applications.

Endophytic Colonization by Beauveria bassiana and Metarhizium anisopliae in Maize Plants Affects the Fitness of Spodoptera frugiperda (Lepidoptera: Noctuidae).

The fall armyworm, Spodoptera frugiperda (Noctuidae; Lepidoptera), is a serious threat to food security as it has the potential to feed on over 353 plant species. To control this insect pest, endophytic colonization of entomopathogenic fungi (EPF) in plants is being considered as a safer and more effective alternative. This study evaluated the efficacy of two EPFs, Beauveria bassiana and Metarhizium anisopliae, for endophytic colonization using foliar spray and seed treatment methods on maize plants, and their impact on the survival, development, and fecundity of S. frugiperda. Both EPF effectively colonized the maize plants with foliar spray and seed treatment methods, resulting in 72-80% and 50-60% colonization rates, respectively, 14 days after inoculation. The EPF negatively impacted the development and fecundity of S. frugiperda. Larvae feeding on EPF-inoculated leaves had slower development (21.21 d for M. anisopliae and 20.64 d for B. bassiana) than the control treatment (20.27 d). The fecundity rate was also significantly reduced to 260.0-290.1 eggs/female with both EPF applications compared with the control treatment (435.6 eggs/female). Age-stage-specific parameters showed lower fecundity, life expectancy, and survival of S. frugiperda when they fed on both EPF-inoculated leaves compared with untreated leaves. Furthermore, both EPFs had a significant effect on population parameters such as intrinsic (r = 0.127 d-1 for B. bassiana, and r = 0.125 d-1 for M. anisopliae) and finite rate (λ = 1.135 d-1 for B. bassiana, and λ = 1.1333 d-1 for M. anisopliae) of S. frugiperda compared with the control (r = 0.133 d-1 and λ = 1.146 d-1). These findings suggest that EPF can be effectively used for the endophytic colonization of maize plants to control S. frugiperda. Therefore, these EPFs should be integrated into pest management programs for this pest.