Date of Award
1-21-2014
Document Type
Dissertation
Degree Name
Doctor of Philosophy (PhD)
Department
Applied Science
First Advisor
Mariya Khodakovskaya
Abstract
Receptor kinases are the main group of signal recognition structures in plants. The large number and diversity of these receptors suggest that they perform major roles in a complex regulatory network of growth, development, and physiological responses. The ERECTA gene is a leucine-rich, receptor-like kinase that affects plant growth rates, stomatal patterning, transpiration efficiency, bacterial pathogen resistance, inflorescence and floral organ morphology, and leaf polarity. The ability to manipulate the ERECTA pathway in members of the Solanaceae family can reveal fundamental mechanisms including regulation of fruit and tuber development. This knowledge may enable changes in plant architecture and growth rates that can improve crop productivity. Manipulating ERECTA signaling in tomato plants by downregulation of the pathway using a dominant-negative version of the Arabidopsis ERECTA gene (AtΔ,Kinase) is the main objective of this research project. Morphological analysis of AtER:AtΔ,Kinase tomato lines demonstrates that a truncated Arabidopsis ERECTA protein is able to interact with the endogenous ER signaling in tomato, negatively affecting the growth of transgenic tomato plants during the first stages of development. AtER:AtΔ,Kinase tomato lines exhibited modifications in plant architecture, a delay in flowering/fruiting time and an increase of leaf stomata density compared with wild type plants. An expression profile shows that AtΔ,Kinase is predominantly located in the apexes and green fruits of transgenic tomato plants. Additionally, our results show an association between ERECTA gene family signaling and stress signaling in tomato plants. AtΔ,Kinase transgenic plants present enhanced tolerance to water-deficit stress compared with wild type tomato. The implications of this research are that it may be possible to clarify the functions of ERECTA gene family in crops and to bring a biotechnological approach for agriculture application through induction of drought tolerance by regulation of plant size.
Recommended Citation
Villagarcia, Hector Ernesto, "Regulation of Growth and Stress Tolerance in Tomato Plants by Expression of a Dominant-Negative Version of Erecta Gene from Arabidopsis thaliana" (2014). Theses and Dissertations. 482.
https://research.ualr.edu/etd/482
