Waheed Akram

Hypersensitive response - A biophysical phenomenon of producers.

Hypersensitive response/reaction is a form of the cellular demise frequently linked alongside plant resistance against pathogen infection. Main transducers for this reaction are the intermediates of reactive oxygen and ion fluxes which are plausibly needed for hypersensitive response (Hpr Sen Rsp). An immediate and enormous energy production and its intra-cellular biochemical conduction are imperative for an Hpr Sen Rsp to be occurred. A number of studies proved that there are such diverse types of factors involved in triggering of Hpr Sen Rsp that morphologies of dead cells have become a vast topic of study. Hpr Sen Rsp could play a frolic role in plants as certain programmed cellular disintegrations in other organisms, to restrict pathogen growth. In fact, Hpr Sen Rsp can be involved in all types of tissues and most of the developmental stages.

First Report of Curvularia lunata Causing Leaf Spots on Sorghum bicolor from Pakistan

In October 2012, reddish brown, oblong lesions with chlorotic centers were observed on the leaves of Sorghum bicolor in Punjab Province, Pakistan. Early symptoms appeared as reddish brown circular spots on the leaves. These spots increased in size and coalesced to form oblong lesions. Entire fields were severely affected by the disease. Pathogen isolations were made on malt extract agar (MEA) media. Symptomatic leaf samples were cut into 4 to 6 mm2 pieces, surface sterilized (10% bleach for 1 min, 90% ethanol for 30 sec) and rinsed in sterilized water several times, followed by air drying. These samples were plated onto 2% MEA media, supplemented with 10 mg/liter chloramphenicol, and incubated at 25°C for 6 days in the dark. A mitosporic fungus of dark brown colony, bearing large stroma, appeared on the media. Conidiophores were brown, septate, geniculate, simple or unbranched, with dark brown scar. Conidia were brown, straight to pyriform, with 3 to 4 cells, with large and curved central cells, smooth walled, ranging in size from 7.3 to 21.26 μm, and produced apically in a sympodial manner. Based on morphological characteristics, the pathogen was identified as Curvularia lunata (Wakk.) Boedijn. (1,2). Morphological identification was also confirmed by the First Fungal Culture Bank of Pakistan (FCBP), Institute of Agricultural Sciences, University of the Punjab, Lahore, Pakistan, and samples were submitted to FCBP (Accession No. 1201). The fungus was further identified by amplifying internal transcribed spacer region sequences (ITS1, rDNA, ITS2) by using ITS4 and ITS5 primers (4). The resulting 584-bp sequence was submitted to GenBank with Accession No. HG326308. This sequence showed 99% homology with C. lunata strain pingxiang (GenBank Accession No. JQ701897), causing leaf spots of lotus in China. Pathogenicity assay was conducted on 20-day-old seedlings of S. bicolor variety Indian Gold, grown from surface sterilized seeds. Fifteen replicate plants were sprayed with a spore suspension of 1 × 106 spore/ml in distilled sterilized water, prepared from 1-week-old fungal culture, grown in the dark on 2% MEA media. Five replicate plants were sprayed with distilled sterilized water as control. Plants were covered with transparent polyethylene bags to retain moisture and enhance disease development, and kept in a greenhouse at ~30°C. Bags were removed after 5 days of incubation. Inoculated plants developed lesions similar to those observed on naturally infected plants. No symptoms were observed on control plants. The pathogen was re-isolated from infected leaves, and the morphology features were again studied, matching those of the pathogen isolated from field samples. Curvularia leaf spot diseases, caused by different Curvularia species, have been previously found on many grass species worldwide (3). To our knowledge, this is the first report of C. lunata leaf spots on S. bicolor in Pakistan. References: (1) M. B. Ellis. Dematiaceous Hyphomycetes. Commonwealth Mycological Institute, Kew, Surrey, England, 1971. (2) F. B. Rocha et al. Austral. Plant Pathol. 33:601, 2004. (3) J. D. Smith et al. Fungal diseases of amenity turf grasses. E & F.N. Spon., New York, 1989. (4) T. J. White et al. Page 315 in: PCR Protocols: A Guide to Methods and Applications. Academic Press, San Diego, CA, 1990.

Analysis of Microbial Biochemical Inducting Nutritional Contents in Barley

Current study focuses the biochemical analysis of the metabolites of Acetobacter aceti to explore bioactive compounds inducing nutritional elements (including vitamins) in barley seeds. Thirteen chemical compounds were isolated using bioactivity guided assay and chromatographic analyses of bacterial extracts. The, principal component analysis (PCA) indicated the most active biochemicals among them. It was resulted into five chemical compounds (i.e. Mevalonic Acid, Quinolinic Acid, Pyridoxic Acid, p.Aminobenzoate and and α-Oxobutanoic acid), which were highly associated with increased quantities of phytosterols, phenols and tested vitamins. A solvent system consisting upon chloroform:ethanol (4:1) was recommended as the best solvent system for extraction of active compounds from bacterial metabolites. Moreover, the mechanisms have been proposed according to which plant pathways were directed towards elevated biosynthesis of nutritional elements. Significant quantities of Mevalonic Acid were concluded into induction of is

Phytochemical relationship of Euphorbia helioscopia and Euphorbia pulcherrima with Lactuca sativa

Allelopathy is an important phenomenon that modifies the ecosystem. A plant can enhance or reduce the growth of other plant due to the presence of a number of allelochemicals in its different parts. Euphorbia helioscopia and Euphorbia pulcherrima are medicinal plant species. Both these species are collected from wild resources for various purposes. To reduce the pressure on wild population, it is important to bring them into cultivation. Therefore, the allelopathic effects of E. helioscopia and E. pulcherrima on the growth of lettuce seeds were studied. Three different concentrations (2%, 4% and 6%) of five different solvents (methanol, acetone, ethyl acetate, n-hexane and distilled water) were used to estimate the allelopathic potential of the above-mentioned Euphorbia species. Results indicated a non-significant growth inhibitory effect of both plants on lettuce seeds. Different extracts reduced the growth of test plant to some extent but this inhibition was not significant. From the observed results, it was concluded that the studied Euphorbia species, being medicinally important crops, can be introduced as intercrop with other cash crops.

The beneficial role of potassium in Cd-induced stress alleviation and growth improvement in Gladiolus grandiflora L.

ABSTRACT Heavy metal contaminated agricultural soils are one of the most important constraints for successful cultivation of crops. The current research was conducted to evaluate the role of potassium (K) on plant growth and amelioration of cadmium (Cd) stress in Gladiolus grandiflora under greenhouse conditions. G. grandiflora corms were sown in media contaminated with 0 (C), 50 (Cd50) and 100 (Cd100) mg Cd kg−1 soil. The plants growing in Cd-contaminated media exhibited reduced gas exchange attributes, chlorophyll (Chl) contents, vegetative and reproductive growth as compared to control. The plants raised in Cd contaminated media showed reduced nutrition yet higher Cd contents. However, supplementation of 60 mg Kg−1 K in treated plants (C+K, Cd50+K and Cd100+K) improved quantity of total soluble protein and proline (Pro) along with activity of antioxidant enzymes including superoxide dismutase (SOD), catalase (CAT), peroxidase (POD) and ascorbate peroxidase (APX) under Cd stress. Similarly, K supplementation reduced the level of malondialdehyde (MDA) and hydrogen peroxide (H2O2) in treated plants. Potassium supplemented plants exhibited better vegetative and reproductive growth. The improved stress tolerance in K supplemented plants was attributed to the reduced quantity of MDA and H2O2, enhanced synthesis of protein, proline, phenols, flavonides and improved activity of antioxidant enzymes. The present research supports the application of K for alleviation of Cd stress in G. grandiflora.

Tomato Plant Proteins Actively Responding to Fungal Applications and Their Role in Cell Physiology

The pattern of protein induction in tomato plants has been investigated after the applications of pathogenic and non-pathogenic fungal species. Moreover, particular roles of the most active protein against biological applications were also determined using chromatographic techniques. Alternaria alternata and Penicillium oxalicum were applied as a pathogenic and non-pathogenic fungal species, respectively. Protein profile analysis revealed that a five protein species (i.e., protein 1, 6, 10, 12, and 13) possessed completely coupled interaction with non-pathogenic inducer application (P. oxalicum). However, three protein species (i.e., 10, 12, and 14) recorded a strong positive interaction with both fungal species. Protein 14 exhibited the maximum interaction with fungal applications, and its role in plant metabolism was studied after its identification as protein Q9M1W6. It was determined that protein Q1M1W6 was involved in guaiacyl lignin biosynthesis, and its inhibition increased the coumarin contents in tomato plants. Moreover, it was also observed that the protein Q9M1W6 takes significant part in the biosynthesis of jasmonic acid and Indole acetic acid contents, which are defense and growth factors of tomato plants. The study will help investigators to design fundamental rules of plant proteins affecting cell physiology under the influence of external fungal applications.

Genetic diversity and biogeography of T. officinale inferred from multi locus sequence typing approach

Taraxacum officinale (Asteraceae) is widely distributed weedy plant used as a traditional medicinal herb. The population genetics and historical biogeography of this plant have remained relatively unexplored. This study explores phylogeny, population genetics and ancestral reconstructions adopting multi locus sequence typing (MLST) approach. MLST sequences dataset was generated from genomics and chloroplast DNA sequences obtained from 31 T. officinale haplotypes located in 16 different countries. Phylogenetic analysis distributed these haplotypes in well differentiated geographic clades. The study suggested a close relationship between Europe and adjacent Asian countries. Populations of these regions predominantly formed common haplogroups, showed considerable level of gene flow and evidence for recombination events across European and Asian population. Biogeographical inferences obtained by applying statistical dispersal-vicariance analysis (S-DIVA) and Bayesian binary MCMC (BBM) analysis showed that T. officinale was putatively originated in Europe. Molecular clock analysis based on ITS dataset suggested that the divergence between Europe and East Asian populations can be dated to 1.07 Mya with subsequent dispersal and vicariance events. Among different spatial process long distance seed dispersal mediated by wind had potentially assisted the population expansion of T. officinale.

Modelling of cotton leaf curl viral infection in Pakistan and its correlation with meteorological factors up to 2015

This study mathematically correlates intensity of cotton leaf curl virus (CLCuV) with environmental factors (i.e. temperature, rainfall and humidity) and whitefly population in the agriculture system of Pakistan. It has been concluded that humidity and rainfall were directly correlated with the disease. Vector (whitefly) population was the third most influential factor in defining CLCuV intensity, which was also strictly associated with the mean monthly temperature of Pakistan. Mathematical interrelation developed in this study has a capability to predict disease intensity of future months. Therefore, it will be helpful to agriculturists for controlling the viral infection among agricultural areas of Pakistan. The study strongly recommends the immediate practice of measures controlling vector populations just after the detection of small elevations in mean monthly temperature.

Comparative studies on phytochemistry, antibacterial and antifungal properties of Alstonia scholaris and Millettia pinnata

Phytochemical profiles and antimicrobial activities of A. scholaris and M. pinnata extracts have been assessed. Test microorganisms were evaluated for their susceptibility against aqueous, methanol, ethanol, n-hexane and chloroform extracts from leaves of both plant species. Antibacterial effects were evaluated against eight bacterial species (three gram positive and five gram negative) of high economic importance, whereas antifungal effects were evaluated against three devastating fungal pathogens. Maximum number of phytochemical groups was noted in methanol and aqueous extracts of both plant species which showed the best antibacterial activities. This indicates that methanol extract contained a wide range of antibiotic compounds, whereas ethanol extract was least effective against tested bacterial and fungal species. This study supports the use of plant origin pesticides against pathogenic microbes.