ABSTRACT
AIMS: The present work investigates the implication of leaf spot disease on the antioxidant potential and commercial value of pharmaceutically important constituents of Withania somnifera, a high-valued medicinal plant. METHODS AND RESULTS: Leaf spot disease was induced in W. somnifera by inoculating Alternaria alternata (Fr.) Keiss. pathogen. Total polyphenolic content and antioxidant potential showed a significant decrease during leaf spot disease. Evaluation of pharmaceutically active constituents withaferin A, withanone and withanolide A utilizing high-performance liquid chromatography showed a significant decrease in diseased samples as compared to healthy ones. Quantitative expression of major genes involved in withanolide biosynthesis also showed down-regulation in diseased samples. Alterations in the ultra-structure of chloroplasts were also analysed under transmission electron microscopy to get a better insight into the changes of withanolide biosynthesis in leaf during disease infestation. CONCLUSIONS: The present work suggests that when the pathogenic fungus invades the host plants, it evokes multiple responses, which could be studied at various levels. The knowledge gained from this work will provide appropriate rationale for controlling the bio-deterioration of the pharmaceutically active metabolites in W. somnifera and development of suitable strategies against leaf spot disease. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first study to investigate the effect of leaf spot disease on the human health-promoting constituents and withanolide biosynthesis in this high-valued medicinal plant.
Subject(s)
Alternaria/physiology , Plant Leaves/microbiology , Withania/microbiology , Withanolides/metabolism , Humans , Plant Diseases/microbiology , Plant Leaves/chemistry , Plant Roots/chemistry , Plant Roots/metabolism , Plants, Medicinal/chemistry , Plants, Medicinal/metabolism , Triterpenes/analysis , Triterpenes/metabolism , Withania/chemistry , Withanolides/analysisABSTRACT
The buffalo population of Uttar Pradesh (UP) constitutes 26.1% of the total buffalo population of India, yet this population has not been classified into distinct breeds or subpopulations due to lack of systematic study. Genetic variation at 30 microsatellite loci was examined and statistical analysis was carried out to reveal genetic diversity, demographic parameters of these buffaloes and to investigate the existence of population substructures underlying geographical distribution. The mean number of alleles per locus was 13.26 and mean effective number of alleles was 3.74, whereas mean observed and expected heterozygosities were found to be 0.57 and 0.67 in UP buffaloes. Principal component analysis (PCA) based on allele frequency data revealed subclustering of UP buffalo population. Bayesian analysis result also revealed clear membership of individuals into five clusters indicating a genetic subdivision within the UP buffalo population. The buffaloes of Western and Central regions of UP were subtly separated while buffaloes of Tarai area and Bhadawari buffaloes revealed distinctive population structure. The buffaloes of Mau, Ballia and Ghazipur districts of Eastern region also had a distinctive genetic structure. The analysis of data on buffaloes of Indo-Gangetic plains revealed that population was in mutation drift equilibrium. The observed mean M ratio in the population was above the critical significance value (Mc) suggesting that it has not suffered any severe reduction in effective population size. The statistical tests revealed a historical constancy of size of buffalo in this geographical area. The high level of genetic variability indicates UP buffalo population is a vast reservoir of genetic diversity and this shall help in taking informed conservation decisions and sustainable utilization.
Subject(s)
Buffaloes/genetics , Genetic Variation/genetics , Genotype , Animals , DNA/blood , DNA/chemistry , Gene Frequency , Genetic Drift , Genetics, Population , India , Microsatellite Repeats , Polymerase Chain Reaction , Principal Component AnalysisABSTRACT
India possesses a total buffalo population of 105 million out of which 26.1% inhabit Uttar Pradesh. The buffalo of Uttar Pradesh are described as nondescript or local buffaloes. Currently, there is no report about the genetic diversity, phylogenetic relationship and matrilineal genetic structure of these buffaloes. To determine the origin and genetic diversity of UP buffaloes, we sequenced and analysed the mitochondrial DNA D-loop sequences in 259 samples from entire Uttar Pradesh. One hundred nine haplotypes were identified in UP buffaloes that were defined by 96 polymorphic sites. We implemented neutrality tests to assess signatures of recent historical demographic events like Tajima's D test and Fu's Fs test. The phylogenetic studies revealed that there was no geographic differentiation and UP buffaloes had a single maternal lineage while buffaloes of Eastern UP were distinctive from rest of the UP buffaloes.