Inducible knock-down of GNOM during root formation reveals tissue-specific response to auxin transport and its modulation of local auxin biosynthesis.
In plants, active transport of auxin plays an essential role in root development. Localization of the PIN1 auxin transporters to the basal membrane of cells directs auxin flow and depends on the trafficking mediator GNOM. GNOM-dependent auxin transport is vital for root development and thus offers a useful tool for the investigation of a possible tissue-specific response to dynamic auxin transport. To avoid pleiotropic effects, DEX-inducible expression of GNOM antisense RNA was used to disrupt GNOM expression transiently or persistently during embryonic root development. It was found that the elongation zone and the pericycle layer are the most sensitive to GNOM-dependent auxin transport variations, which is shown by the phenotypes in cell elongation and the initiation of lateral root primordia, respectively. This suggests that auxin dynamics is critical to cell differentiation and cell fate transition, but not to cell division. The results also reveal that GNOM-dependent auxin transport could affect local auxin biosynthesis. This suggests that local auxin biosynthesis may also contribute to the establishment of GNOM-dependent auxin gradients in specific tissues, and that auxin transport and local auxin biosynthesis may function together in the regulatory network for initiation and development of lateral root primordia. Thus, the data reveal a tissue-specific response to auxin transport and modulation of local auxin biosynthesis by auxin transport.
Department of Cell and Developmental Biology, College of Life Science and State Key Laboratory of Hybrid Rice, Wuhan University, Wuhan 430072, China.
Jingzhe
J
Guo
Jun
J
Wei
Jian
J
Xu
Meng-Xiang
MX
Sun
D017360:Arabidopsis / Q000166:cytology / Q000235:genetics* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D001692:Biological Transport; D003907:Dexamethasone; D018506:Gene Expression Regulation, Plant; D055785:Gene Knockdown Techniques; D017930:Genes, Reporter; D020662:Guanine Nucleotide Exchange Factors / Q000235:genetics* / Q000378:metabolism; D007210:Indoleacetic Acids / Q000378:metabolism*; D009928:Organ Specificity; D010641:Phenotype; D010937:Plant Growth Regulators / Q000378:metabolism*; D018517:Plant Roots / Q000166:cytology / Q000235:genetics / Q000378:metabolism; D030821:Plants, Genetically Modified; D016372:RNA, Antisense / Q000235:genetics; D018749:RNA, Plant / Q000235:genetics; D036226:Seedlings / Q000166:cytology / Q000235:genetics / Q000378:metabolism
D029681:Arabidopsis Proteins; C088087:GNOM protein, Arabidopsis; D020662:Guanine Nucleotide Exchange Factors; D007210:Indoleacetic Acids; D010937:Plant Growth Regulators; D016372:RNA, Antisense; D018749:RNA, Plant; D003907:Dexamethasone
Arabidopsis; GNOM; auxin biosynthesis; auxin transport; inducible gene expression; root.