Trichomes are specialized structures and are classified into two types: glandular and non-glandular. Their functions are related with plant defense strategies. The developmental pathway knowledge about glandular trichomes formation still scarce. Since the most of efforts were put in studies about Arabidopsis trichome development, which glandular trichomes are absent. The genus Solanum has a great diversity of trichomes, especially glandular ones (types I, IV, VI and VII). The study of such structures is gaining more prominence due to the production of some secondary metabolites that act against herbivory. The resistance to herbivory is proposed as the result of three requirements: i) the ability to form trichomes, ii) the location of leaf trichomes on the face properly and iii) the ability of trichomes to synthesize allelochemicals. Wild type species are considered genetic resources for cultivated tomato (S. lycopersicum), such as S. galapagense and S. habrochaites. Those wild species has natural genetic variations that affect these three requirements. Thus, previous studies identified the natural variations Galapagos enhanced tricomes (Get), which determines the formation of trichomes type I and IV in adaxial face of the leaves; Galapagos acyl sugar (gas) which enhances production of the acyl allelochemic trichomes sugar in type I and IV and pincushion-like (Pik), which produces modified type VI trichomes. This project aims to relate the development of glandular trichomes under control of thus natural variation (Get, Pik, and , gas) with hormones: jasmonic acid (JA), cytokinin (CK) and estrigolactona (SL). The main approach used will be the analysis of double mutants in tomato, where genotypes deficient or insensitive to JA (jai-1 mutant), CK (transgenic 35S :: CKX2) and SL (transgenic 35S :: asCCD7) will be combined with Get , Pik and gas mutants. Will also be tested the genetic interaction between Get and Pik with mutations Lanata (La) and Wooly (Wo), which produce plants with high density of trichomes (not glandular types III and V). This study will be performed with all genotypes in the same genetic background, represented by the tomato cultivar Micro-Tom (MT), a model plant choice for scientific studies. This project represents an attempt to unveil mechanisms of great ecological and economic importance, and can increase our knowledge about the hormonal function of three classes, one of which, the SL still very little known, having been recently discovered.
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