Poster: Vegetative development

Abs # 324: Study of T-DNA Tagged Mutants which Affect Inosine-Uridine Nucleoside Hyrolase Gene Expression in Arabidopsis

Presenter:	Jinn, Tsung-Luo , Jinnt@ntu.edu.tw
Authors	Jinn, Tsung-Luo  (A) (B)  Chang,  Chih-Wei  (A) (B)
Affiliations:	(A): Department of Life Science and Institute of Plant Biology (B): National Taiwan University, 106 Taipei, Taiwan

In this study, we identified two gain-of-function mutants, selected in the T1 generation, crl1-1D (creased leaf 1-1 Dominant) and crl1-2D with a wrinkled curling inward and narrow leaf phenotype.The fertility was lower than wild type and some of the self-crossed progenies ceased to develop further after the first two leaves were initiated. Southern blots showed two T-DNA insertions with different patterns were detected in each line, indicating that crl1-1D and crl1-2D were independent mutants. Inverse PCR identified one of the T-DNA insertion sites in each mutant. Noteworthily, the T-DNA insertion sites are both located at the down-stream region of At2g36310 (CRL1), and is distant from each other by 307 bp, which encodes a putative inosine-uridine nucleoside hydrolase. Northern analysis using CRL1 gene as a probe shown that the transcript levels were higher in mutants than that in wild type. To recapitulate the phenotype of crl1-1D and crl1-2D in wild type, CRL1 was overexpressed. No transgenic plant with wrinkled leaf was detected, instead 35S::CRL1 seedlings showed phenotype similar to the loss-of-function mutant wuschel (wus). The WUS transcripts were not detected by RT-PCR analysis in 35S::CRL1 lines with the wus phenotype. The expression pattern of CRL1 was studied by RT-PCR and in transgenic plants carrying a GUS gene under the control of CRL1 promoter. The CRL1 messenger RNA and GUS activity were detected in whole young seedling, and the expression level was higher in SAM than that in leaf and stem. In summary, we suggest that overexpression of the CRL1 might affect the SAM activity rather than leaf morphology.