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Genetic Characterization of Quorum Sensing Dependent Bacterial Isolates Associated With Legumes

Thesis Info

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Author

Khan, Sami Ullah

Program

PhD

Institute

Quaid-I-Azam University

City

Islamabad

Province

Islamabad.

Country

Pakistan

Thesis Completing Year

2014

Thesis Completion Status

Completed

Subject

Botany

Language

English

Link

http://prr.hec.gov.pk/jspui/handle/123456789/904

Added

2021-02-17 19:49:13

Modified

2024-03-24 20:25:49

ARI ID

1676726286035

Similar


The present study aimed at characterizing two Acyl Homoserine Lactone (AHLs) producing bacteria isolates nodulating (cultivated and wild) legumes. The isolate from cultivated Pisum sativum was named as Pcc1; while that isolated from the wild species Alysicarpus buleurifolius was called Pcc21. These isolates were selected from a set of twenty potential isolates obtained from the culture collection of Department of Plant Sciences, Quaid-i-Azam University. The initial screening of isolates was done for AHLs production using Chromobacterium violaceum (CV026) as indicator strain. These AHLs were further characterized for their diversity through TLC and LC/MS analyses. The TLC assay was done to study the size and range of the AHLs, revealing diverse nature of AHLs produced by the Pcc1 and Pcc21. The small bacteriocin assay revealed that Pcc1 produced AHLs which are a characteristic of CinI system, however, the Pcc21 was found negative. The phylogenetic analyses based on 16S rRNA sequences depicted the isolate Pcc1 as Rhizobium leguminosarum while that of Pcc21 as Sinorhizobium meliloti. Pcc1 being Rhizobium was further studied for the RhiR system which controls nodulation in host plants. Thus the RhiR gene was amplified and sequenced and using bioinformatics tools its protein sequences was generated. The sequence data thus generated and its comparison with the RhiR protein sequences in silico revealed useful information for the isolate (Pcc1) under study such as various domains homolgous to the LuxR transcriptional protein. To characterize it further mutation of RhiR locus was done using Pk19 mob vector, the induced mutation reduced the AHLs production and nodulation efficiency. The Pcc21 presented an interesting case. The 16S rRNA analysis revealed its identity as Sinorhizobium meliloti and it was isolated from root nodules of a wild legume species Alysicarpus bupleurifolius, this has been the first report on the novel symbiotic association between S. meliloti and Alysicarpus bupleurifolius. The study further characterized the AHL diversity produced in symbiosis. The TLC and LC-MS profiles revealed production of a diverse array of AHLs that ranged from short chain C4-HSL to long chain C12- HSL. It was observed that isolates thriving in younger nodules produced AHL abundance and points to the possible presence of more than one synthase system, as previously described in Rm1021 and AK63. The isolation of a strain producing wide ranging AHL molecules provides an opportunity to investigate the complex genetics of AHL production in S. melitoti. It was further revealed that the AHLs produced by Pcc21 were rather diverse. In an analysis the introduction of WspR plasmid in Pcc21 decreased the amount of exopolisaccharides produced in the system, however it did not affect the overall amount of AHLs produced.
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عقل مند بادشاہ

عقل مند بادشاہ

کسے شہر وچ اک غریب بندہ رہندا سی۔ انتہائی نیک تے محنتی، سارا دن محنت کردا تے جو کجھ ملدا اوس اتے ربّ دا شکر ادا کردا۔ بچت کر کے اوس دس ہزار روپے جمع کر لئے سن۔ اچانک اوس نوں ضروری کم لئی دوجے شہر جانا پیا۔ اوس پیسے نال لے جاون دیبجائے اپنے گوانڈھی کول امانت رکھوا دتے۔ پر امانت دیندے ویلے کوئی گواہ نئیں سی موجود تے نہ ای اوس امانت دی کوئی رسید لئی۔

چھ مہینیاں پچھوں جدوں اوہ بندہ واپس آیا تاں اوس نے گوانڈھی کولوں اپنی امانت منگی۔ تاں گوانڈھی صاف مکر گیا۔ الٹا اوس دی بے عزتی وی کیتی۔ اوہ ہر روز امانت لین جاندا پر گوانڈھی اوس دی کوئی گل نہ سندا۔ شام نوں اوہ تھک کے گھر واپس آ جاندا۔ آخر کار اوس نے فیصلہ کیتا کہ اوہ اپنا مقدمہ بادشاہ دی عدالت وچ لے کے جاوے گا۔ اوہ بادشاہ دی عدالت وچ اپڑیا تے بادشاہ نوں دسیا کہ اوس کولوں غلطی ہوئی اے کہ اوس بغیر کسے گواہ تے رسید دے دس ہزار روپے گوانڈھی کول امانت راکھوے سن پر ہن اوہ اوس دی امانت واپس نئیں کردا۔ ایس لئی میرے پیسے مینوں واپس لے کے دیو۔

بادشاہ نے اوس نوں آکھیا کہ بناں ثبوت دے میں اوس نوں گرفتار نئیں کر سکدا۔ پر اک تجویز اے کہ میں کل عصر دی نماز توں بعد سیر کردا اوس بندے دی دوکان اتے آوے گا۔ توں وی اوتھے آ جاویں۔ میں تینوں جھک کے سلام کراں گا۔ توں بڑی لاپرواہی نال اوس دی جواب دیویں ایسے طرں میں تیرے نال جو وی گلاں کراں توں انتہائی لاپرواہی نال اوہناں دا جواب دینا ایں۔

بادشاہ دے دسے ہوئے منصوبے دے تحت اگلے اوہ بندہ...

أفكار أرنولد توينبي عن الحضارة الإسلامية ومدى تأثره برؤية ابن خلدون: دراسة وصفية و تحليلية

Ibn e Khaldun (1406 C.E.) has been an imminent scholar and well known for his work in the study of civilization. His vision regarding Civilization holds the significant place according to the philosophers of history. Arnold J. Toynbee (1975 C.E.) is one such prominent thinker who not only applauded the thoughts of Ibn e Khaldun but was influenced by Ibn e Khaldun’s views as it can be seen in Toynbee’s book: “A Study of History”. As a philosopher of history, he has much contribution in the field; He interlinks History with civilization. He presented a thoughtful book surrounding his civilizational vision; which explains the causes of world’s ups and downs. Although he presented a quality research about the division of the civilizations in the light of religion, many aspects of his work need to be reassessed. As per his understanding of world civilizations, he represents twenty-one civilizations, but with the passage of time, the number reduces and now only five are left in the contemporary epoch. According to him, religion has played significant role in the rise and fall of civilizations through their various stages. This research will highlight his thought about Islam through a comparison between Toynbee and Ibn e Khaldun’s Islamic civilizational thoughts. The study will also mention several problems in his approach to the Islamic Civilization. Furthermore, along with due importance of both scholars in the subject of history, their authoritative status will be stated. This research aims to discuss some misconceptions of the West that are based on Toynbee's understating of Islamic civilization and history. And, consequently, it intends to improve relations between people of the west and east.

Organotin Iv Complexes of O, N, O and S, S Donor Ligands Derived from Dibasic Acids for Biological Applications

Herein we reports the synthesis of new mono and diorganotin(IV) complexes of Schiff baes/hydrazones with [O, N, O] and dithiocarbamates with [S, S] donor ligands. The methodologies described herein includes; the synthesis of five versatile Schiff bases/hydrazones ligands; N'', N''-4-bis(2-hydroxybenzylidene)oxalohydrazide(H4L1), N'', N''-4-bis(2-hydroxylbenzylidene)malonohydrazide (H4L2), N′, N′-4-bis(2- hydroxybenzylidene)succinohydrazide (H4L3), N′, N′-4-bis(2-hydroxybenzylidene)glutarohydrazide (H4L4) and N′, N′-4-bis(2-hydroxybenzylidene)adipohydrazide (H4L5). Herein the thesis also embodied another series of five dithiocarbamates ligands of the types; dipotassium-2, 2-oxalylbis(hydrazine-1-carbodithioat) (K2L1), dipotassium-2, 2-malonylbis(hydrazine-1-carbodithioate) (K2L2), dipotassium2, 2''-succinylbis(hydrazine-1-carbodithioate) (K2L3), dipotassium-2, 2''-glutaroylbis(hydrazine-1-carbodithioate) (K2L4) and dipotassium-2, 2''-adipoylbis(hydrazine-1carbodithioate) (K2L5). For the synthesis of organotin(IV) complexes the reaction between Schiff bases/ hydrazone ligands with [O, N,O] donor sites, mono- and diorganotin(IV)chlorides/oxides were carried out at various reaction conditions and obtained fifty new organotin Schiff bases/hydrazone complexes. The reaction between dithiocarbamae ligands with [S, S] binding sites, mono- and diorganotin(IV)chlorides were unsuccessful and end up with desulfurized isothiocynates. The structural and coordination chemistry of ligands with O, N, O and S, S binding mode/sites and thier organotin(IV) complexes were investigated by using FT-IR and single crystallographic studies in the solid sate. The solution chemistry of these complexes was investigated through mass spectrometry and some multinuclear (1H, 13C and 119Sn) spectal studies. The results revealed that Schiff bases/hydrazones coordinate to tin through a tridentate mode using [O, N, O] binding mode. The structural analysi of single crystal by X-ray technique showed that organotincomplexes procured from hydrazone with tridentate lignads (O, N, O), mono- and diorganotin(IV) chlorides exhibited distorted octahedral (oh) and distorted trigonal bipyramidal (tbp) geometry respectively.Based on the computational studies; the trigonal bipyramidal complexes showed a Sn···O tetrel bonding/interaction in the solid state. A computational study, in combination with the quantum theory of atoms in molecules (QTAIM) shows that the Sn···O interactions involved here are purely electrostatic in nature with little covalent character and leads to a shorter Sn···O [3.480(2 Å)] inter-atomic bond distance as compare to the reported “sum of van der Waals radii (3.92 Å)”. However, these types of interaction cannot be seen in the compounds when the phenyl /butyl groups or when the methylene spacer (-CH2-) between the two-hydrazone fragments is increased replaces the methyl groups. Finally, all the complexes were screened for anticancer activities using carbopaltin as a standard drug. The diorgantotin hydrazone complexes;wheremethyl and phenyl groups are attached to tin(IV)showed reasonable activities due tosolubility problems but the dibutyltin(IV) complexes of the hydrazone [O, N, O] ligands showed excellent activities and have been used as representative sample (compounds) against various cancer cell lines (HL-60, MCF-7 and HeLa ) obtained from human being. It is assumed that the high cytotoxic activities of the dibutyl tin(IV) complexes are due to its lipophilic character and can be compared with the activity of the standard drug (carboplatin). These results might be helpful in the rational drug designing of those complexes containing the dibutyl moiety.