A New Regimen To Research The Crosstalk Of Auxin And Other Phytohormones

Auxin is probably the most investigated plant hormone and is known to be involved in virtually every aspect of plant growth and development, which tailor plant growth and morphology to environmental conditions. Over the past decades several auxin biosynthesis, auxin transport, auxin-responsive genes and gene families involved in the signaling of auxin have been identified. In plants, networks of signaling events regulated by different interacting phytohormones are integrated to control developmental processes. How to find out the interaction between auxin and other Phytohormones that controls plant development is the new question about auxin research?The microarray data could be further examined using various bioinformatic tools for classifying the genes that participate in the crosstalk between auxin and other Phytohormones, but the genetic screening of senescence mutants maybe still fruitful in understanding the genetic regulatory mode and in isolating the regulatory genes that participate in the crosstalk between auxin and other Phytohormones.In this thesis, a new regimen was established that can used to screen the mutants that participate in the crosstalk between auxin and GA, auxin and CTKs. The region ,for example, auxin/GA ,consist of: 1) seed germination in the presence of the TIBA; 2) transfer of the seedlings to a medium containing exogenous auxin （1-naphthalene acetic acid, NAA） and GA （GA₃,）; 3) transfer of the seedlings to a GA₃-only medium for all subsequent growth. When used to research the crosstalk between auxin and CTKs, just change GA₃ with 6-BA.Under this regimen, auxin and GA interact to induce internodes elongation between rosette leaves, auxin and CTKs interact to change root that become green and larger. Polar auxin transport （PAT） appears to have an important role on this synergistic interaction. The mutants of auxin or GA signaling has different response to this regimen, suggested that this regimen can be used to screen the mutant that participate in the crosstalk between auxin and other Phytohormones.