title: The tomato SlIAA15 is involved in trichome formation and axillary shoot development.
abstract: The Aux/IAA genes encode a large family of short-lived proteins known to regulate auxin signalling in plants. Functional characterization of SlIAA15, a member of the tomato (Solanum lycopersicum) Aux/IAA family, shows that the encoded protein acts as a strong repressor of auxin-dependent transcription. The physiological significance of SlIAA15 was addressed by a reverse genetics approach, revealing that SlIAA15 plays multiple roles in plant developmental processes. The SlIAA15 down-regulated lines display lower trichome number, reduced apical dominance with associated modified pattern of axillary shoot development, increased lateral root formation and decreased fruit set. Moreover, the leaves of SlIAA15-inhibited plants are dark green and thick, with larger pavement cells, longer palisade cells and larger intercellular space of spongy mesophyll cells. The SlIAA15-suppressed plants exhibit a strong reduction in type I, V and VI trichome formation, suggesting that auxin-dependent transcriptional regulation is required for trichome initiation. Concomitant with reduced trichome formation, the expression of some R2R3 MYB genes, putatively involved in the control of trichome differentiation, is altered. These phenotypes uncover novel and specialized roles for Aux/IAAs in plant developmental processes, clearly indicating that members of the Aux/IAA gene family in tomato perform both overlapping and specific functions.
authors.affiliation: Key Laboratory of Functional Gene and Regulation Technologies under Chongqing Municipal Education Commission, Bioengineering College, Chongqing University, Chongqing 400044, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Deng
authors.affiliation: Key Laboratory of Functional Gene and Regulation Technologies under Chongqing Municipal Education Commission, Bioengineering College, Chongqing University, Chongqing 400044, China.
authors.forename: Yingwu
authors.initials: Y
authors.lastname: Yang
authors.affiliation: Key Laboratory of Functional Gene and Regulation Technologies under Chongqing Municipal Education Commission, Bioengineering College, Chongqing University, Chongqing 400044, China.
authors.forename: Zhenxin
authors.initials: Z
authors.lastname: Ren
authors.affiliation: Université de Toulouse, INP-ENSA Toulouse, Génomique et Biotechnologie des Fruits, Avenue de l'Agrobiopole, BP 32607, Castanet-Tolosan, F-31326, France.|INRA, Génomique et Biotechnologie des Fruits, Chemin de Borde Rouge, Castanet-Tolosan, F-31326, France.
authors.forename: Corinne
authors.initials: C
authors.lastname: Audran-Delalande
authors.affiliation: Université de Toulouse, INP-ENSA Toulouse, Génomique et Biotechnologie des Fruits, Avenue de l'Agrobiopole, BP 32607, Castanet-Tolosan, F-31326, France.|INRA, Génomique et Biotechnologie des Fruits, Chemin de Borde Rouge, Castanet-Tolosan, F-31326, France.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Mila
authors.affiliation: Key Laboratory of Functional Gene and Regulation Technologies under Chongqing Municipal Education Commission, Bioengineering College, Chongqing University, Chongqing 400044, China.
authors.forename: Xinyu
authors.initials: X
authors.lastname: Wang
authors.affiliation: Key Laboratory of Functional Gene and Regulation Technologies under Chongqing Municipal Education Commission, Bioengineering College, Chongqing University, Chongqing 400044, China.
authors.forename: Hongli
authors.initials: H
authors.lastname: Song
authors.affiliation: Key Laboratory of Functional Gene and Regulation Technologies under Chongqing Municipal Education Commission, Bioengineering College, Chongqing University, Chongqing 400044, China.
authors.forename: Yinghong
authors.initials: Y
authors.lastname: Hu
authors.affiliation: Université de Toulouse, INP-ENSA Toulouse, Génomique et Biotechnologie des Fruits, Avenue de l'Agrobiopole, BP 32607, Castanet-Tolosan, F-31326, France.|INRA, Génomique et Biotechnologie des Fruits, Chemin de Borde Rouge, Castanet-Tolosan, F-31326, France.
authors.forename: Mondher
authors.initials: M
authors.lastname: Bouzayen
authors.affiliation: Key Laboratory of Functional Gene and Regulation Technologies under Chongqing Municipal Education Commission, Bioengineering College, Chongqing University, Chongqing 400044, China.
authors.forename: Zhengguo
authors.initials: Z
authors.lastname: Li
mesh_terms: D000595:Amino Acid Sequence; D002467:Cell Nucleus / Q000378:metabolism; D015536:Down-Regulation / Q000235:genetics; D018506:Gene Expression Regulation, Plant; D007210:Indoleacetic Acids / Q000378:metabolism; D018551:Solanum lycopersicum / Q000033:anatomy & histology* / Q000235:genetics / Q000254:growth & development* / Q000648:ultrastructure; D008969:Molecular Sequence Data; D005810:Multigene Family / Q000235:genetics; D010802:Phylogeny; D018515:Plant Leaves / Q000033:anatomy & histology* / Q000235:genetics / Q000648:ultrastructure; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D018520:Plant Shoots / Q000033:anatomy & histology* / Q000235:genetics / Q000254:growth & development* / Q000648:ultrastructure; D011401:Promoter Regions, Genetic / Q000235:genetics; D021381:Protein Transport; D012097:Repressor Proteins / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D013347:Subcellular Fractions / Q000378:metabolism
chemical_list: D007210:Indoleacetic Acids; D010940:Plant Proteins; D012097:Repressor Proteins