Isolation And Functional Analysis Of Aux/IAA Genes In Tomato

The phytohormone auxin is central to myriad of aspects of plant growth and developmental processes. At the cellular level, auxin regulates cell division, extension and differentiation. On a whole-plant level, auxin plays an essential role in processes such as apical dominance; lateral/adventitious root formation, tropisms, fruit set and development, vascular differentiation and embryogenesis. This multiplicity of regulatory activities has spurred considerable interest in mechanisms of auxin signaling and response. Although auxin may regulate some cellular responses (such as expansion or polarity) through direct effects on membrane or cytoskeletal functions, auxin also regulates expression of numerous genes whose products probably perform most developmental responses. Three major classes of early auxin response genes have been identified from various plant species: Aux/IAA, SAUR and GH3. Auxin induces many of these genes rapidly, specifically, and in the absence of de novo protein synthesis, and these genes are considered primary response genes. Of these, the protein products of the Aux/IAA genes are the best characterized.Biochemical, molecular, and genetic researchs on model plant Arabidopsis thaliana show that the Aux/IAA proteins play a critical role in auxin signaling and plant development. The aux/iaa mutants of Arabidopsis thaliana exhibit a variety of auxin-related developmental phenotypes, including altered phototropism/gravitropism, root formation, apical dominance, stem/hypocotyl elongation, leaf expansion, and leaf formation in the dark. Since tomato (Solarium lycopersicum) plants have fresh fruits, they are the good model plants for leaf morphology and fruit development research. Physiological studies have shown that auxin is related on the fruit setting, expanding and ripening of tomato fruit. And exogenous auxin would promote parthenogenesis. Discovering the functions of tomato Aux/IAA proteins, which were involved in auxin signal transduction, would make out that how the auxins influence the tomato root formation, leaf morphology, flower and fruit development, and illustrate the molecular mechanism of auxin signaling. These research results would also indicator us to use auxins, auxins-like moleclor, auxin transport inhibitor rationally in tomato plant.Functional identification of tomato Aux/IAA genes is the aim of our research. And making out the molecular mechanism of these genes' developmental function is our main topic. Another topic of this research is to create some transgenic mutants for auxin signal...