AI SearchPhysiological roles of catalases in protection of Agrobacterium tumefaciens from hydrogen peroxide and superoxide toxicity (Record no. 87893)
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| 000 -LEADER | |
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| fixed length control field | 05652nas|a2200469 a 4500 |
| 005 - DATE AND TIME OF LATEST TRANSACTION | |
| control field | 20260818171902.0 |
| 008 - FIXED-LENGTH DATA ELEMENTS--GENERAL INFORMATION | |
| fixed length control field | 040621s2004 th uu|m rtt 0| a1eng d |
| 035 ## - SYSTEM CONTROL NUMBER | |
| System control number | .b11929893 |
| 099 #9 - LOCAL FREE-TEXT CALL NUMBER (OCLC) | |
| Classification number | AIT Diss. no.EV-04-01 |
| 100 0# - MAIN ENTRY--PERSONAL NAME | |
| Personal name | Benjaphorn Prapagdee |
| 245 10 - TITLE STATEMENT | |
| Title | Physiological roles of catalases in protection of Agrobacterium tumefaciens from hydrogen peroxide and superoxide toxicity |
| 260 ## - PUBLICATION, DISTRIBUTION, ETC. | |
| Place of publication, distribution, etc. | Pathum Thani, Thailand : |
| Name of publisher, distributor, etc. | Asian Institute of Technology, |
| Date of publication, distribution, etc. | 2004 |
| 300 ## - PHYSICAL DESCRIPTION | |
| Extent | 149 p. : |
| Other physical details | ill. |
| 490 1# - SERIES STATEMENT | |
| Series statement | Dissertation ; |
| Volume/sequential designation | no. EV-04-01 |
| 500 ## - GENERAL NOTE | |
| General note | A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Technical Science, Asian Institute of Technology; Inter-University Program on Environmental Toxicology, Technology and Management, Chulabhom Research Institute and Mahidol University |
| 502 ## - DISSERTATION NOTE | |
| Dissertation note | Thesis (Ph.D.) - Asian Institute of Technology, 2004 |
| 520 ## - SUMMARY, ETC. | |
| Summary, etc. | Agrobacterium tumefaciens is a phytopathogenic bacterium causing crown gall tumor in many dicotyledonous plants. During plant-microbe interactions, one of the initial active plant defense responses against invading microorganisms involves a rapid production and accumulation of reactive oxygen species. A. tumefaciens must overcome this oxidative burst in order to proliferate in the host plant. Here, physiological r oles of c atalases and bacterial growth phases on protection of A. tumefaciens from H202 and menadione (MD), superoxide generator, toxicity were investigated. During stationary phase, cells became more resistant to H202 than during exponential phase. A. tumefaciens possesses two catalase genes namely katA encodes a bifunctional catalase-peroxidase and catE for a mono functional c atalase. Visualization o f c atalases using gel staining revealed that katA was highly expressed at exponential phase and then declined as cells entered stationary phase of growth while catE was expressed throughout growth phases and was enhanced during stationary phase. Nevertheless, total catalase activity increased 2-fold during stationary phase of growth relative to exponential phase. Them utants of k atA and c atE were constructed. A katA mutant was more sensitive to H20 2 than the parental strain at both exponential and stationary phases _indicating that K atA plays a primarily protective role against H20 2 toxicity during all phases of growth. Conversely, inactivation of catE did not cause any significant changes in the level of H202 resistance. Moreover, the katA catE double mutant was extremely susceptible to H202 during both exponential and stationary phases relative to the katA or catE single mutant suggesting the physiological function of catE in H202 protection. Furthermore, the stationary phase cells of the katA catE double mutant were still more resistance to H202 than those of other phases. The data suggested the essential function of katA and catE in stationary phase resistance to H20 2 in A. tumefaciens and also the existence of stationary phase dependent mechanisms that rendered bacterial cells highly resistant to H20 2. The physiological function of the bifunctional catalase-peroxidase KatA in the protection of A. tumefaciens from MD was evaluated in the katA mutant. Unexpectedly, katA mutant was highly sensitive to the MD. The expression of katA from a plasmid vector complemented the MD hypersensitive phenotype. A. tumefaciens possesses an additional catalase gene, a monofunctional catalase encoded by catE. Neither inactivation nor high-level expression of the catE gene altered the MD resistance level. Moreover, heterologous expression of the catalase-peroxidase from Burkholderia pseudomallei, but not the monofunctional catalase from Xanthomonas campestris could restore normal levels of MD resistance to the katA mutant. Inactivation of putative genes encoding organic hydroperoxide scavenging enzymes such as tsa (a homolog of the tsa family), bcp (bacteriofeITitin co-migratory protein) and ohr (organic hydroperoxide resistance) do not cause any detectable changes in the MD resistance level. The level of MD resistance shows a direct correlation with the level of KatA catalaseperoxidase activity. This is a novel role for KatA and suggests that resistance to MD toxicity is mediated by a new, and as yet unknown, mechanism in A. tumefaciens. |
| 650 #0 - SUBJECT ADDED ENTRY--TOPICAL TERM | |
| Topical term or geographic name entry element | Agrobacterium tumefaciens |
| 650 #0 - SUBJECT ADDED ENTRY--TOPICAL TERM | |
| Topical term or geographic name entry element | Catalase |
| 650 #0 - SUBJECT ADDED ENTRY--TOPICAL TERM | |
| Topical term or geographic name entry element | Hydrogen peroxide |
| 700 0# - ADDED ENTRY--PERSONAL NAME | |
| Personal name | Skorn Mongkolsuk, |
| Relator term | Chairperson |
| 700 0# - ADDED ENTRY--PERSONAL NAME | |
| Personal name | Preeda Pakpian, |
| Relator term | Examination Committee |
| 700 0# - ADDED ENTRY--PERSONAL NAME | |
| Personal name | Paiboon Vattanaviboon, |
| Relator term | Examination committee |
| 700 0# - ADDED ENTRY--PERSONAL NAME | |
| Personal name | Suvit Loprasert, |
| Relator term | Examination committee |
| 700 0# - ADDED ENTRY--PERSONAL NAME | |
| Personal name | Chongrak Polprasert, |
| Relator term | Examination Committee |
| 700 1# - ADDED ENTRY--PERSONAL NAME | |
| Personal name | Farrand, Stephen K., |
| Relator term | Examination committee |
| 710 2# - ADDED ENTRY--CORPORATE NAME | |
| Corporate name or jurisdiction name as entry element | Chulabhom Research Institute, |
| Relator term | Scholarship donor |
| 710 2# - ADDED ENTRY--CORPORATE NAME | |
| Corporate name or jurisdiction name as entry element | Mahidol University, |
| Relator term | Scholarship donor |
| 710 2# - ADDED ENTRY--CORPORATE NAME | |
| Corporate name or jurisdiction name as entry element | AIT Fellowship, |
| Relator term | Scholarship donor |
| 810 2# - SERIES ADDED ENTRY--CORPORATE NAME | |
| Corporate name or jurisdiction name as entry element | Asian Institute of Technology. |
| Title of a work | Dissertation ; |
| Volume/sequential designation | no. EV-04-01 |
| 856 ## - ELECTRONIC LOCATION AND ACCESS | |
| Materials specified | Full-Text |
| Uniform Resource Identifier | <a href="http://203.159.5.9/ait-thesis/detail.php?q=B08442">http://203.159.5.9/ait-thesis/detail.php?q=B08442</a> |
| 907 ## - LOCAL DATA ELEMENT G, LDG (RLIN) | |
| a | .b11929893 |
| b | mnait |
| c | u |
| 902 ## - LOCAL DATA ELEMENT B, LDB (RLIN) | |
| a | 240417 |
| 998 ## - LOCAL CONTROL INFORMATION (RLIN) | |
| Operator's initials, OID (RLIN) | 0 |
| Cataloger's initials, CIN (RLIN) | 040618 |
| First date, FD (RLIN) | m |
| -- | a |
| -- | u |
| -- | 0 |
| 945 ## - LOCAL PROCESSING INFORMATION (OCLC) | |
| l | mnait |
| 945 ## - LOCAL PROCESSING INFORMATION (OCLC) | |
| l | mnarc |
| 942 ## - ADDED ENTRY ELEMENTS (KOHA) | |
| Koha item type | 22-AIT Thesis (Replacement) |
| 942 ## - ADDED ENTRY ELEMENTS (KOHA) | |
| Koha item type | 40-Archives |
| 909 ## - LOCAL ITEMS USED | |
| Barcode | Barcode : 30050120726038 |
| CREATED | CREATED : 2012-08-21 |
| RECORD Id | RECORD # : i12687832 |
| LPATRON | LPATRON : 0 |
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| 909 ## - LOCAL ITEMS USED | |
| Barcode | Barcode : 30050160004585 |
| CREATED | CREATED : 2016-02-02 |
| RECORD Id | RECORD # : i12876641 |
| LPATRON | LPATRON : 0 |
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| Withdrawn status | Lost status | Damaged status | Not for loan | Home library | Current library | Shelving location | Date acquired | Total checkouts | Full call number | Barcode | Date last seen | Copy number | Price effective from | Koha item type |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Available for Loans | Asian Institute of Technology Library | Asian Institute of Technology Library | AIT Publications | 18/08/2026 | AIT Diss. no.EV-04-01 | 30050120726038 | 18/08/2026 | 3 | 18/08/2026 | 22-AIT Thesis (Replacement) | ||||
| Available for Loans | Asian Institute of Technology Library | Asian Institute of Technology Library | Archives | 18/08/2026 | AIT Diss. no.EV-04-01 | 30050160004585 | 18/08/2026 | 18/08/2026 | 40-Archives |