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Effect of Indole-3-Acetic Acid and Flavonoids on Association of Maize Roots and Phytostimulant Endophytic Fungi

Thesis Info

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Author

Mehmood, Asif

Program

PhD

Institute

Abdul Wali Khan University

City

Mardan

Province

KPK

Country

Pakistan

Thesis Completing Year

2019

Thesis Completion Status

Completed

Subject

Botany

Language

English

Link

http://prr.hec.gov.pk/jspui/bitstream/123456789/10684/1/Ph.D%20Thesis%20of%20Asif%20Mehmood_after%20defense-1.pdf

Added

2021-02-17 19:49:13

Modified

2024-03-24 20:25:49

ARI ID

1676725972492

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Chemical communication between microbes and their host is the first step toward the establishment of any association. Plant roots release a variety of signaling molecules that naturally screens the surrounding microbes for association. Current study focuses on isolation of IAA and flavonoids producing endophytic fungi and the influence of these metabolites on root-endophyte interaction. For this purpose, 16 endophytic fungi were isolated from Asphodelus tenifolius and Withenia somnifera collected from the dry areas of district Malakand. Based on screening, for their efficiency to produce metabolites (IAA, ammonia and flavonoids) used in plant growth, five endophytes were selected for further study including their identification by sequence homology of the internal transcribed spacer (ITS) region of 18 S rDNA, their plant growth promoting potential, identification of phenols and flavonoids produced by these strains alone or in co-culture with maize and their colonization in maize root under different treatments. The selected strains including wl1, wlg2 and greenish were identified as species of Aspergillus awamori, Aspergillus nomius and Aspergillus fumigatus while two strains (Pz and wlw) belonges to Fusarium culmorum and Fusarium oxysporum. The selected endophytes produced significant amount of IAA ranging between 24.2 and 86.4 µg/mL where maximum production recorded in Aspergillus nomius wlg2. The most efficient flavonoids producing strains were Fusarium culmorum Pz and A. nomius wlg2 with 275 and 261 µg/mL flavonoids respectively in their cultures. LC-ESI-MS/MS analysis of the culture filtrate resulted in the identification of 3 flavonoids (calycosin, dihydroxyflavone and pratensein) from Fusarium culmorum strain Pz and 5 flavonoids (4-bromo 3nitroacetophenone, dihydroxyflavone, apigenin-6,8-di-c-glycoside, rutin, 3hydroxyphelorutin,3,5-di-c-hexoside from A. nomius wlg2. Production of flavonoids and fungal growth were significantly compromised when the endophytes were exposed to 100 µL of cinnamic acid (CA). Interestingly, the CA exposed cultures had only one species of flavonoids indicating the influence of this compound on flavonoids biosynthesis. For instance, CA exposed cultures of F. culmorum and A. nomius had only dihydroxyflavone and apigenin6,8-di-c-glycoside respectively. Phenols were also produced by the isolatesin a concentration ranging from 303.8 µg/mL (A. awamori w11) to 617.6 µg/mL (A. nomius wlg2). Phenolic acid, chlorogenic acid was identified in cultre filtrate of A. nomius wlg2 whereas two phenolic acids including cumaric acid and caffoly-d- glucoses were identified in culture filtrate of endophyte F. culmorum Pz using LC-ESI-MS/MS.All the selected strains significantly improved growth parameters viz shoot length, root length, fresh and dry weight of maize seedlings when treated with endophyte culture filtrate or grown in co-culture with the endophyte under hydroponics. F. culmorum Pz and A. nomius wlg2 showed the best results in culture filtrate treated maize seedlings. In co-culture experiment maximum increase of shoot and root length (33% and 60% respectively over control) corresponding to A. nomius wlg2 and Fusarium wlw.Exogenous application of IAA and GA3 significantly improved growth of maize seedlings under hydroponics. Exogenous IAA significantly promoted maize root colonization by all the isolates and increased shoot length. Additionally, the rate of colonization was higher in zone of division of root in all IAA treated seedlings. Maximum promotion in shoot length (53%) was recorded in seedlings hosted endophyte A nomius wlg2 or F. oxysporum wlw in addition to foliar IAA application. Contrary to this, GA3 promoted seedling growth but had no positive role like IAA in root colonization by endophytes The maize seedlings released significant amount of flavonoids, phenols and sugars in their root exudates. Three different types of flavonoids (Quercetagatin, rhamnocitrin and 7,2,dihydroxy-4-methoxyl isoflavan) were detected in root exudate of control maize seedlings, however, only quercetagtin was present in exudates of CA treated seedlings. Quality and quantity of flavonoids released from maize root were influenced by the endophytes and also the maize associated endophytes showed a change in flavonoids profile. For instance, the coculture of maize seedlings and endophyte Fusarium culmorum Pz had quercetagtin and rhamnocitrin and calycosin indicating a clear qualitative change in the flavonoids profile. Likewise apigenin-6,8-di-c-glycoside, letuloin, calycosin, ramnocitrin and quercetagatin were detected in root exudates of seedlings associated with wlg2. These results are quite interesting because letuloin and calcyosin were neither present in exudates of control nor in that of wlg2 colonized seedlings. The new flavonoids might have a role in plant-endophyte interactions.CA or yucassin treatment arrested shoot growth, however normal growth (or even better than control in case of wlw) was observed in endophytes associated seedlings. Root growth and seedling biomass was also negatively influenced by CA or yucasin treatment however endopytes associated seedlings supressed the activities of CA or yucasin and seedlings have normal roots and biomass (or even better than control in case of F. oxysporum wlw, A. nomius wlg2 and F. culmorum Pz). All the isolates were capable to colonize maize roots where wlg2 was the most efficient one. CA and yucasin inhibited biosynthesis of flavonoids and IAA by the plants accompanied by reduced efficiency of endophytes to colonize maize roots. CA and yucasin inhibited biosynthesis of flavonoids and IAA by the plants accompanied by reduced efficiency of endophytes to colonize maize roots. However foliar CA or yucasin did not affect exudation of sugars but seedlings associated with endophytes and received these inhibitors improved exudation of sugars. Interestingly, flavonoids, letuloin and calcyosin were neither present in exudates of control nor in that of wlg2 colonized seedlings. Fungal flavonoids calycosin and apigenin-6,8-di-c-glycoside, and maize flavonoids ramhnocitrin andquercetagtin were involved in root endophyte interaction. To conclude, this work reveals that plant root-fungal endophyte association is animated by a complex chemical dialogue between both the partners where IAA, phenols, flavonoids and sugars are among the key players. The study also urges for further investigation to completely understand the mechanism by exploring the exact role of each component of the dialogue leading to successful association.
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جس رزق سے آتی ہو پرواز میں کوتاہی

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خود داری حیات نے جُھکنے دیا نہ سر
حسرت سے اُن کا نقشِ قدم دیکھتے رہے
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فضاؤں میں محو پرواز طائرِ خوش الحان بھی اپنارزق حاصل کر رہا ہے ،منبر رسول صلی اللہ علیہ و آلہٖ وسلمپر بیٹھ کر واعظ شیریں بیان بھی اپنارزق حاصل کر رہا ہے، ظلمات ِشب میں سیاہ پتھر پر رینگنے والے کیڑے مکوڑے بھی اپنارزق حاصل کرتے ہیں، آفتاب کی کرنوں سے خائف چمگادڑ بھی اپنے پیٹ کی آگ بجھا کر سوتی ہے۔ شاہین پرواز کی بلندیوں پراپنا رزق حاصل کرتا ہے اور گدھ مردار کے پاس بیٹھ کر اپنارزق حاصل کرتا ہے، کسان ہل چلا کر، پانی لگا کر اور رات سانپ کے سروں کو مسل کر اپنا رزق حاصل کرتا ہے اور راہزن لوٹ مار اور غارتگری سے اپنا رزق حاصل کرتا ہے، قاضی کرسی منصب پر بیٹھ کر اپنا رزق حاصل کرتا ہے...

ظاهرة تزويج القاصرات من منظور شرعي

According to traditional-religious-culture the early age marriages are very common custom especially in rural areas. The act of marring girls in early ages is considered to be a good practice in these constituencies; in contrast, the holy Quran has provided some logical guidelines to reject this idea. In the holy Quran “men” are instructed to marry as per their choice, which reveals, it is necessary for a “man” to be adult (Baligh) for marriage. Considering this fact, how it is possible that a man can be permitted to have a non-adult (Nabaligh) life partner? In this regard, marriages between Adult and Non-adult, Non-adult and Non-adult are not permitted because it is against the right of equality. Further, the holy Quran instructs the guardians of the orphans to return them their valuables when reach to the age of Nikah; which reveals that there is a particular standard of age set for Nikah, if it is not so, why the holy Quran has made this bounding for the guardians of the orphans? As per the guidance of the holy Quran, it is clear that Nikah requires both man and women not only to be physically adult/mature but also mentally adult/mature. In this connection, it has been highlighted that Nikah which is a physical contract requires a particular age for man and woman which however cannot be an age of Non-adult.

An Appraisal of Illiteracy Reduction Plans and Designing a Low Cost Model to Improve Literacy Rate in Pakistan

Government of Pakistan has launched various illiteracy reduction plans from time to time to promote literacy rate in the country but these plans could not achieve the targets. This study was designed to appraise these illiteracy reduction plans and to design a low cost model to improve literacy rate in Pakistan. The main objectives of the study were: to appraise the illiteracy reduction plans introduced in Pakistan, from time to time, to identify the needs and problems of the direct affectees (all the illiterates above the age of 10 years), to know the ground realities regarding implementation of illiteracy reduction plans/projects at Government and NGOs level and to design a low cost model to improve the literacy rate in Pakistan. The population of the study was comprised of Educationists i.e. Ph.D. degree holders in Education, Executives working in the top level management in policy formation, plan designing, project development and program development, Executives working in National Planning Commission, Provincial Secretary, Additional Secretary, Deputy Secretary and EDOs (Education and literacy), Literacy teachers, Heads of different NGOs, Community representatives and Direct beneficiaries (the brick makers, manual workers, laborers, peasants etc). Snowball sampling technique was used to find the most relevant persons (respondents) for different illiteracy reduction programmes in different areas for the conduct of this research study. viA mixed-method research design was used i.e. data was quantitative and qualitative. For quantitative data a questionnaire was developed at five point rating scale ranging from ‘1’ indicating strongly disagree to ‘5’ indicating strongly agree; a selection of ‘3’ indicating uncertain/don’t know. For qualitative data some open ended questions were included in the questionnaire. An interview schedule was also developed for Head of NGOs, community representatives and direct beneficiaries. Data collection was started from the person who had been involved for long with the illiteracy eradication programmes. On his identification the other respondent was selected. Overall 1200 questionnaires were sent to the respondents but 998 questionnaires were got back. In this way, data was collected from 1348 (998 questionnaires and 350 interviews) respondents. Main findings of the study showed that need assessment was not carried out before launching illiteracy reduction programs, objectives of the illiteracy reduction programmes were not relevant to the literacy needs of the participants, local community was not involved in the running the literacy centers, religious leaders, intellectuals and retired personnel were not invited to support the illiteracy eradication programmes, and political instability in the country was a hurdle in the achievement of the targets of the illiteracy eradication programmes. In the light of the findings of the study, a low cost model was designed to improve the literacy rate in Pakistan. The proposed model was presented to 10 experts in the discipline of education for its validation. The model was improved in the light of experts’ opinion. They were satisfied that this low cost model will be useful for increasing the literacy rate in Pakistan.