Abstract
Secondary wall is synthesized only in limited tissues including xylem of stems, anthers and siliques. In this study, we systematically analyzed functions of NAC transcription factors using CRES-T and found that the expression of the chimeric NST1 repressor induced indehiscent anther due to the loss of secondary wall thickenings (SWT) in anther endocecium. Furthermore, the plant expressing NST2 chimeric repressor and the double T-DNA tagged line of NST1 and NST2 also showed the same phenotype. This phenotype of the tagged line was restored by the complementation of NST1 or NST2 expressed by their own promoters. On the other hand, over-expression of NST1 or NST2 induced ectopic SWT in various tissues. The promoter activities of NST1 and NST2 were observed in tissues where SWT occurs. In this report, we will discuss the mechanism that regulates SWT in various tissues and the function of NST3, another gene related to SWT.
