Abstract
BackgroundThe Arabidopsis thaliana gene SPATULA (SPT), encoding a bHLH transcription factor, was originally identified for its role in pistil development. SPT is necessary for the growth and development of all carpel margin tissues including the style, stigma, septum and transmitting tract. Since then, it has been shown to have pleiotropic roles during development, including restricting the meristematic region of the leaf primordia and cotyledon expansion. Although SPT is expressed in roots, its role in this organ has not been investigated.ResultsAn analysis of embryo and root development showed that loss of SPT function causes an increase in quiescent center size in both the embryonic and postembryonic stem cell niches. In addition, root meristem size is larger due to increased division, which leads to a longer primary root. spt mutants exhibit other pleiotropic developmental phenotypes, including more flowers, shorter internodes and an extended flowering period. Genetic and molecular analysis suggests that SPT regulates cell proliferation in parallel to gibberellic acid as well as affecting auxin accumulation or transport.ConclusionsOur data suggest that SPT functions in growth control throughout sporophytic growth of Arabidopsis, but is not necessary for cell fate decisions except during carpel development. SPT functions independently of gibberellic acid during root development, but may play a role in regulating auxin transport or accumulation. Our data suggests that SPT plays a role in control of root growth, similar to its roles in above ground tissues.
Highlights
The Arabidopsis thaliana gene SPATULA (SPT), encoding a basic helix-loophelix (bHLH) transcription factor, was originally identified for its role in pistil development
SPT is necessary for multiple developmental aspects of plant development analysis of SPT function has been confined to the shoot, SPT is expressed in the root as well (Additional file 1; [24])
In order to analyze the possible function of SPT in this region, the root meristem of spt-2 and spt-11 mutants was compared to that of their respective wild types (Landsberg erecta (L. er) and Columbia-0 (Col-0)
Summary
The Arabidopsis thaliana gene SPATULA (SPT), encoding a bHLH transcription factor, was originally identified for its role in pistil development. The primary root of Arabidopsis thaliana has a simple and consistent organization of cell types [1]. Within the root apical meristem (RAM), stem cells surround a group of four mitotically less active cells called the Quiescent Center (QC; [1]). In Arabidopsis, the zygote divides asymmetrically to form an apical and a basal daughter cell. The uppermost cell of the suspensor becomes the hypophysis, which divides transversely to make an upper and lower hypophyseal cell. The upper hypophyseal cell forms the QC and the lower hypophyseal cell forms the columella stem cells and the central root cap. The rest of the RAM arises from derivatives of the apical cell [3,4,5]
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
