Date of Graduation

Fall 2010

Degree

Master of Science in Plant Science (Agriculture)

Department

College of Agriculture

Committee Chair

Wenping Qiu

Keywords

Vitis aestivalis, ethylene response factor, mitogen activated kinase, WRKY transcription factor, plant defense.

Subject Categories

Plant Sciences

Abstract

Vitis aestivalis ‘Norton' grapevines are more resistant to disease and stress, but are less productive than Vitis vinifera cultivars. Identification and characterization of V. aestivalis ‘Norton' defense genes VaERF3a, VaERF3b, VaERF4, VaERF5, VaMAPKK, VaWRKY4, and VaWRKY30 can unveil mechanisms for resistance and tolerance. Amino acid analyses indicated that VaERF3a, VaERF3b, VaERF4 and VaERF5 contain an AP2 DNA binding domain, VaMAPKK has a serine/threonine kinase domain, and VaWRKY4 and VaWRKY30 include a WRKY domain. Nucleotide and amino acid sequence analysis suggested that VaERF3a and VaERF3b may be paralogous, while VaWRKY4 and VaWRKY30 are two different genes. V vinifera homologues of each gene were also found in the newly sequenced whole genone of PN40024. V. aestivalis ‘Norton' defense genes were transformed into Nicotiana tabacum via an Agrobacterium tumefaciens-mediated transformation procedure. Viable shoots were not generated from the VaWRKY4 and VaWRKY30 transformations. RNA blots were used to confirm the presence of VaERF3a, VaERF3b and VaMAPKK transgenic N. tabacum plants. The results showed that VaERF3b-transgenic plants were more tolerant to salt and Pseudomonas syringe infection than VaERF3a-, VaMAPKK- and nontransgenic N. tabacum plants. Preliminary tests showed that V. aestivalis ‘Norton' berries respond more quickly to methyl jasmonic acid than V. vinifera berries.

Copyright

© Tabitha Michele Shaver

Campus Only

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