Poster: Vegetative Development

Abs # 426: A flavin monooxygenase-like overexpression mutant with narrow, down-curling leaves and long petioles phenotypes in Arabidopsis.

Presenter:	Jinn, Tsung-Luo , Jinnt@ntu.edu.tw
Authors	Jinn, Tsung-Luo  (A)   Li, Yi-Hang  (A)
Affiliations:	(A): Department of Botany, National Taiwan University

Leaf is an essential organ with vital functions for plant growth and development, however, little is known about its genetic controls of morphogenesis because of the combination effect of genes from photosynthesis, CO₂ fixation, phytohormones and heteroblasty, etc. Here we establish a system by using T-DNA knock-out tagging vector, pPZP202:BAR:SK, with highly convenient and efficient for gene rescue, to identify genes that may involve in leaf morphogenesis. The yucca4, an Arabidopsis T-DNA tagged line, with narrow, down-curling leaf and long petiole phenotypes in T1 generation, is a gain-of-function mutant. YUCCA4 is a flavin monooxygenase (FMO)-like enzyme taking part in IAA biosynthesis as YUCCA. In yucca4 mutant, YUCCA4 is over-expressed with those phenotypes as well as other auxin-overproduction mutants described before. Interestingly, the T-DNA insertion site in this mutant is at -1.7 kb upstream of YUCCA4, but pPZP202:BAR:SK is not a vector designed for activation tagging. For this reason, we assume that there is probably a negative element in promoter regulating the expression of YUCCA4. In an attempt to identify the regulatory element, we design several promoter constructs of YUCCA4 to carry out promoter::GUS assay in order to clarify the regulation of YUCCA4 for further research.