Endophytic fungal community of Rosa damascena Mill. as a promising source of indigenous biostimulants: Elucidating its spatial distribution, chemical diversity, and ecological functions.

The role of endophytes in maintaining healthy plant ecosystems and holding promise for agriculture and food security is deeply appreciated. In the current study, we determine the community structure, spatial distribution, chemical diversity, and ecological functions of fungal endophytes of Rosa damascena growing in the North-Western Himalayas. Culture-dependent methods revealed that R. damascena supported a rich endophyte diversity comprising 32 genera and 68 OTUs. The diversity was governed by climate, altitude, and tissue type. Species of Aspergillus, Cladosporium, Penicillium, and Diaporthe were the core endophytes of the host plant consisting of 48.8% of the endophytes collectively. The predominant pathogen of the host was Alternaria spp., especially A. alternata. GC-MS analyses affirmed the production of diverse arrays of volatile organic compounds (VOC) by individual endophytes. Among the primary rose oil components, Diaporthe melonis RDE257, and Periconia verrucosa RDE85 produced phenyl ethyl alcohol (PEA) and benzyl alcohol (BA). The endophytes displayed varied levels of plant growth-promoting, colonization, and anti-pathogenic traits. Between the selected endophytes, P. verrucosa and D. melonis significantly potentiated plant growth and the flavonoids and chlorophyll content in the host. The potential of these two endophytes and their metabolites PEA and BA was confirmed on Nicotiana tabacum. The treatments of the metabolites and individual endophytes enhanced the growth parameters in the model plant significantly. The results imply that P. verrucosa and D. melonis are potential plant growth enhancers and their activity may be partially due to the production of PEA and BA. Thus, R. damascena harbors diverse endophytes with potential applications in disease suppression and host growth promotion. Further investigations at the molecular level are warranted to develop green endophytic agents for sustainable cultivation of R. damascena and biocontrol of leaf spot disease.

A Secondary Metabolite of Cercospora sp., Associated with Rosa damascena Mill., Inhibits Proliferation, Biofilm Production, Ergosterol Synthesis and Other Virulence Factors in Candida albicans.

Here we describe the antimicrobial potential of secondary metabolites, fulvic acid (F.A.) and anhydrofulvic acid (AFA), produced by RDE147, an endophyte of Rosa damascena Mill. The endophyte was identified as Cercospora piaropi by ITS and ß-tubulin-based phylogenetic analyses, while chemoprofiling of the endophyte by column chromatography and spectroscopy yielded two pure compounds, F.A. and AFA. The compounds demonstrated different antimicrobial profiles, with AFA suppressing the growth of C. albicans at 7.3 µg ml-1 IC50. Further studies revealed that AFA strongly restricted the biofilm production and hyphae formation in C. albicans by down-regulating several biofilm and morphogenesis-related genes. The time-kill assays confirmed the fungicidal activity of AFA against C. albicans, killing 83.6% of the pathogen cells in 24 h at the MIC concentration, and the post-antibiotic effect (PAE) experiments established the suppression of C. albicans growth for extended time periods. The compound acted synergistically with amphotericin B and nystatin and reduced ergosterol biosynthesis by the pathogen, confirmed by ergosterol estimation and comparative expression profiling of selected genes and molecular docking of AFA with C. albicans squalene epoxidase. AFA also suppressed the expression of several other virulence genes of the fungal pathogen. The study determines the anti-C. albicans potential of AFA and its impact on the biology of the pathogen. It also indicates that Cercospora species may yield potential bioactive molecules, especially fulvic acid derivatives. However, it is imperative to conduct in vivo studies to explore this molecule's therapeutic potential further.

Burkholderia gladioli E39CS3, an endophyte of Crocus sativus Linn., induces host resistance against corm-rot caused by Fusarium oxysporum.

AIM: To investigate the role of the leading saffron endophyte Burkholderia gladioli strain E39CS3 (BG-E39) in the inhibition of corm-rot and induced systemic resistance (ISR) in the host against the saffron specific pathogen, Fusarium oxysporum. METHODS AND RESULTS: We studied the interaction between BG-E39 and the corm-rot pathogen F. oxysporum in vitro and in vivo. BG-E39 strongly inhibited both the F. oxysporum strains and other saffron-specific and non-specific pathogens used in this study. Confrontation and microscopic analyses revealed that the endophyte possessed fungicidal activity against the pathogens and effectively induced cell death in the mycelia. The endophyte produced chitinases as well as ß-1,3-glucanase that may be involved in the pathogen cell wall degradation. BG-E39 did not cause corm-rot in Crocus sativus and the closely related plant, Gladiolus, thus establishing that it is non-pathogenic to these plants. The endophyte reduced corm-rot through antibiosis and enhanced the endogenous jasmonic acid (JA) levels and expression of JA-regulated and other plant defence genes. CONCLUSIONS: The bacterial endophyte BG-E39 provides resistance to the host plant against F. oxysporum corm-rot in nature. SIGNIFICANCE AND IMPACT OF THE STUDY: The current study discovers the role of the saffron endophyte BG-E39 in providing resistance to the host against corm-rot. Therefore, this endophyte is a potential candidate for developing a microbial formulation for the biocontrol of the most common disease of C. sativus.

Incidence of colorectal cancer in Kashmir valley, India.

BACKGROUND: There is wide variation in the incidence of colorectal cancer globally and also within the same country among different racial or ethnic groups. The present population-based study was undertaken to determine the incidence of colorectal cancer in Kashmiri population which is non-migratory and ethnically homogeneous having stable food habits. METHODS: Over a period of one year, all newly diagnosed and histological proved cases of colorectal cancer in all possible areas, where such patients are diagnosed and treated were prospectively registered. RESULTS: A total of 212 cases of colorectal cancers were registered; of them 113 (53.3%) originated in the colon and other 99 (46.7%) in rectum. Male to female ratio was 1.2:1. The crude incidence rate of colorectal cancer was 3.65/100,000; it was 3.78 in males, and 3.50/100,000 in females. The incidence rates for colorectal cancer in Muslims and Hindus were different. The crude incidence rate for colorectal carcinoma was highest for district Srinagar 6.19/100,000 (urban area) and lowest for district Kupwara (rural area) 1.59/100,000. The highest numbers of cases were detected in the age group 55-59 years (n = 34). The age-specific rate for colorectal carcinoma was highest in the age group 55-59 years (17.21/100,000), followed by 65-69 years (14.86/100,000). The age standardized incidence rate was 4.52/100,000 per year. The truncated age adjusted incidence rates in age group 35-64 years was 8.31/100,000; while that for colorectal carcinoma was 8.77/100,000 in males and 7.66/100,000 in females. CONCLUSION: We conclude that the incidence of colorectal cancer in Kashmir valley is similar to that reported in the rest of India.