Syed Waqas Hassan

Malus × domestica (apple) accumulates particularly high amounts of dihydrochalcones in various tissues, with phloridzin (phloretin 2′-O-glucoside) being prevalent, although small amounts of 3-hydroxyphloretin and 3-hydroxyphloridzin are also constitutively present. The latter was shown to correlate with increased disease resistance of transgenic M. × domestica plants. Two types of enzymes could be involved in 3-hydroxylation of dihydrochalcones: polyphenol oxidases or the flavonoid 3′-hydroxylase (F3′H), which catalyzes B-ring hydroxylation of flavonoids. We isolated two F3′H cDNA clones from apple leaves and tested recombinant Malus F3′Hs for their substrate specificity. From the two isolated cDNA clones, only F3′HII encoded a functionally active enzyme. In the F3′HI sequence, we identified two putatively relevant amino acids that were exchanged in comparison to that of a previously published F3′HI. Site directed mutagenesis, which exchanged an isoleucine into methionine in position 211 restored the functional activity, which is probably because it is located in an area involved in interaction with the substrate. In contrast to high activity with various flavonoid substrates, the recombinant enzymes did not accept phloretin under assay conditions, making an involvement in the dihydrochalcone biosynthesis unlikely.

Maize is the 3rd most important agricultural crop in Pakistan with an annual production of 5,701,400 tons. Identification of genetically diverse maize genotype is valuable information which is efficiently used in upcoming maize breeding programs and acquiring specific traits with modification of DNA for different conditions. In current study we reported the genetic diversity among twelve maize genotypes using Randomly Amplified Polymorphic DNA (RAPD). Four oligo decamer primers of were used for the analysis. Young and fresh maize leaves were used for DNA extracted by CTAB extraction procedure. RAPD decamer primers were used for DNA amplification. The PCR results were checked on gel electrophoresis with 1.2% agarose gel having ethidium bromide where DNA bands were separated on the base of size. A total of 301 loci were obtained by using four primers. Bands were score with binary method, 1 for their presence or 0 for the absence. After statistical analysis of all loci, phylogenetic tree was constructed using computer program Dendro UPGMA. The results showed that genotypes FSH-810 and Karamat were the most diverse genotypes having maximum dissimilarity ratio of 66% to each other while Islamabad Gold and Soan-3 were least diverse genotypes with 18% variation. Hence it is recomended that FSH-810 and Karamat genotypes are the ideal candidates for any breeding programs potentially generating maximum variation.

The purpose of this study is to investigate the effect of locally isolated Lactobacillus strains on the degradation of calcium oxalate and calcium phosphate using in vitro analysis. Ten different bacterial strains are isolated from various sources including yogurt, Indian-pickle, rhizosphere and plant root tissue. Results shows that the most efficient strains of Lactobacillus are those isolated from the fermented food sources. L-HMY2 proved to be the most effective strain for the biodegradation of calcium salts (PSI =2.88, OSI = 2.65, pH decrease up to 4.32, EC of calcium phosphate broth = 1366 mS cm?1 and Ca contents in calcium phosphate broth = 187 mg L?1). Moreover, Lactobacilli strains are more effective for the degradation of calcium phosphate than calcium phosphate. This study concludes that these indigenous strains of Lactobacillus are potential candidates for probiotic properties for the preclusion of kidney stone formation and this avenue should be further explored.