Papers by Dr. Masooma Naseer Cheema
Good quality deoxyribonucleic acid (DNA) is the pre-requisite for its downstream applications. Th... more Good quality deoxyribonucleic acid (DNA) is the pre-requisite for its downstream applications. The presence of high concentrations of polysaccharides, polyphenols, proteins, and other secondary metabolites in mango leaves poses problem in getting good quality DNA fit for polymerase chain reaction (PCR) applications. The problem is exacerbated when DNA is extracted from mature mango leaves. A reliable and modified protocol based on the cetyltrimethylammonium bromide (CTAB) method for DNA extraction from mature mango leaves is described here. High concentrations of inert salt were used to remove polysaccharides; Polyvinylpyrrolidone (PVP) and β-mercaptoethanol were employed to manage phenolic compounds. Extended chloroform-isoamyl alcohol treatment followed by RNase treatment yielded 950-1050 µg of good quality DNA, free of protein and RNA. The problems of DNA degradation, contamination, and low yield due to irreversible binding of phenolic compounds and coprecipitation of polysaccharides with DNA were avoided by this method. The DNA isolated by the modified method showed good PCR amplification using simple sequence repeat (SSR) primers. This modified protocol can also be used to extract DNA from other woody plants having similar problems.
Mutagenesis has been used to a good extent to induce genetic variability in plant species to achi... more Mutagenesis has been used to a good extent to induce genetic variability in plant species to achieve the desired genetic variability. To attain maximum useful mutation density per unit genome and comparative effectiveness of γ-rays and Ethyl methanesulfonate (EMS), optimal dose for treatment is the key to success. This study focuses on the development of kill curve in three cotton species (Gossypium arboreum, G. barbadense and G. hirsutum). Four genotypes from each of these Gossypium species were treated with eight varying levels of EMS (0.1 to 0.8%) and two doses of γ-rays (100 to 800 Gy) for kill curve analysis. The data collected on germination percentage, plant height, number of bolls/plant, boll weight, lint yield and its percentage were analyzed and significant interaction among species, genotypes, mutagens and levels of mutagens was observed for all traits under study. Morphologically unusual mutants (rudimentary sparse leaves pattern and broad leaf shape) were also identified from M 1 generations of cotton genotypes. Optimal mutagenic doses were calculated based on survival rate and seed viability, which were considered useful in developing cotton mutagenized populations for forward and reverse genetic studies. EMS observed to be more effective than γ-rays as it generated overall more number of mutants, while later caused higher physical injury in all cotton species.
Calotropis procera, commonly known as "milkweed", possesses long seed trichomes for seed dispersa... more Calotropis procera, commonly known as "milkweed", possesses long seed trichomes for seed dispersal and has the ability to survive under harsh conditions such as drought and salinity. Aquaporins are water channel proteins expressed in all land plants, divided into five subfamilies plasma membrane intrinsic proteins (PIPs), tonoplast intrinsic proteins (TIPs), NOD26-like proteins (NIPs), small basic intrinsic proteins (SIPs), and the unfamiliar X intrinsic proteins (XIPs). PIPs constitute the largest group of water channel proteins that are involved in different developmental and regulatory mechanisms including water permeability, cell elongation, and stomata opening. Aquaporins are also involved in abiotic stress tolerance and cell expansion mechanisms, but their role in seed trichomes (fiber cells) has never been investigated. A large number of clones isolated from C. procera fiber cDNA library showed sequence homology to PIPs. Both expressed sequence tags (ESTs) and real-time polymerase chain reaction (PCR) studies revealed that the transcript abundance of this gene family in fiber cells of C. procera is greater than that of cotton. Full-length cDNAs of CpPIP1 and CpPIP2 were isolated from C. procera fiber cDNA library and used for constructing plant expression vectors under constitutive (2×35S) and trichome-specific (GhLTP3) promoters. Transgenic tobacco plants were developed via Agrobacterium-mediated transformation. The phenotypic characteristics of the plants were observed after confirming the integration of transgene in plants. It was observed that CpPIP2 expression cassette under 2×35S and GhLTP3 promoter enhanced the numbers of stem and leave trichomes. However, 2×35S::CpPIP2 has a more amplified effect on trichome density and length than GhLTP3::CpPIP2 and other PIP constructs. These findings imply the role of C. procera PIP aquaporins in fiber cell elongation. The PIPs-derived cell expansion mechanism may be exploited through transgenic approaches for improvement of fiber staple length in cotton and boosting of defense against sucking insects by enhancing plant pubescence.
To cite this paper: Azmat, M.A., A.A. Khan, H.M.N. Cheema, M. Ashraf and S. Niaz, 2013. Detached ... more To cite this paper: Azmat, M.A., A.A. Khan, H.M.N. Cheema, M. Ashraf and S. Niaz, 2013. Detached leaf assay coupled with microscopic conidial quantification: an efficient screening method for powdery mildew resistance in pea. Int. J. Agric. Biol., 15: 957-962
The outer epidermal layer of the cotton ovule may differentiate in vitro to form a mass of white ... more The outer epidermal layer of the cotton ovule may differentiate in vitro to form a mass of white fluffy fibers in an appropriate liquid medium. The in vitro cultured fibers provide a model for studying not only the cellular physiology and development mechanism but also generate a key resource for promoter evaluation in developing fibers. However, the potential uses of in vitro cultured ovules are restricted due to the frequent problem of bacterial and fungal contamination. In this study, the effect of Ampicillin, Gentamicin and Sodium Azide on cotton fiber development was observed at various concentrations (100 µg/mL, 50 µg/mL and 0.5 µg/mL respectively) which were added in the media as contamination controlling agents. The in vitro grown ovules were evaluated at 5, 10, 15 and 20 DPA (days post anthesis) for fiber length, percent viable ovules producing fiber, ovules fresh weight and ovules dry weight. It was observed that ovules grown on the media containing either Gentamicin or Sodium Azide were unable to initiate normal number of fiber cells. Addition of Ampicillin to cultures enhanced the fiber length, ovule weight and percentage of viable ovules with fibers. The inhibitory effect of Gentamicin on fiber growth was reversible, when ovules were transferred to Gentamicin -free medium within 3 days after culture initiation. However, Sodium Azide resulted in irreversible fiber development inhibition. These results indicate that Ampicillin was not only efficient to control contamination but also enhanced the fiber and ovule development process.
To cite this paper: Indrais, E., H.M.N. Cheema and A. Bashir, 2011. Temporal expression analysis ... more To cite this paper: Indrais, E., H.M.N. Cheema and A. Bashir, 2011. Temporal expression analysis and cloning of cotton (Gossypium hirsutum) fiber genes. Int. J. Agric. Biol., 13: 89-94
The Calotropis procera seed fibers provide an excellent model system to study the genes involved ... more The Calotropis procera seed fibers provide an excellent model system to study the genes involved in fiber elongation, fineness and strength. Expansins constitute one of the important gene families involved in plant cell expansion and other cell wall modification processes. Four homologs of Expansin A gene i.e. CpEXPA1, CpEXPA2, CpEXPA3 and CpEXPA4 were isolated from the cDNA library obtained from fast growing Calotropis procera fibers. These homologs represented typical Expansin A family. Each of them had two conserved domains including GH45 like domain and the putative polysaccharide binding domain. The deduced amino acid sequences of the homologs indicated three conserved motifs: i) eight cysteine residues at N-terminus, ii) four tryptophan residues at C-terminus and iii) a Histidine-Phenylalanine-Aspartate motif in the center of the sequence. The presence of N-terminal signal peptide consisting of hydrophobic amino acids and a transmembrane region in all these expansin isoforms suggests their cotranslational insertion into the endoplasmic reticulum and then transportation to the cell wall by secretory pathway. The relative quantification of the four expansins in root, stem, fiber and leave tissues indicated that the transcripts of CpEXPA1, CpEXPA2, CpEXPA3 and CpEXPA4 are variably transcribed in these tissues. The lowest transcription of all the four Expansin A isoforms was observed in elongating roots indicating that root tissue might be having specific expansins other than those confined to air grown organs. How to cite this article: CHEEMA, H.M.N.; BASHIR, A.; KHATOON, A.; IQBAL, N.; ZAFAR, Y.; MALIK, K.A. ( 2010). Molecular characterization and transcriptome profiling of expansin genes isolated from Calotropis procera fibers.
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Papers by Dr. Masooma Naseer Cheema