CsPI from the perianthless early-diverging Chloranthus spicatus show function on petal development in Arabidopsis thaliana.

Kunmei Su,Zhiduan Chen,Zhenhuan Li

doi:10.1186/1999-3110-55-21

Kunmei Su, Zhiduan Chen + Show 1 more

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https://doi.org/10.1186/1999-3110-55-21

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Abstract

BackgroundIn the floral ABC model, B-class genes comprised of DEFICIENS (DEF)/APETALA3 (AP3) and GLOBOSA (GLO)/PISTILLATA (PI) had been proposed to involve in second and third whorl floral organ development. However, less is known about the function of B-class genes from early-diverging angiosperms. Chloranthaceae is one of the early-diverging angiosperm families. In this study, we characterized the role of the PI-like gene CsPI cloned from Chloranthus spicatus which have the simplest perianthless bisexual flowers.ResultsThe expression profile analysis reveals high levels of CsPI mRNA in stamens in Chloranthus spicatus, with weak distribution in leaves and other floral organs. Nevertheless, CsPI rescued both stamen and petal development in Arabidopsis thaliana pi-1 mutants and caused partially conversion of sepals into petaloid organs in wild-type Arabidopsis thaliana plants. Yeast two-hybrid analysis showed that CsPI can form not only homodimers but also heterodimers with proteins encoded by Arabidopsis thaliana and Chloranthus spicatus AP3-like genes.ConclusionsThese results suggested that CsPI has an ancestral function on stamen development and that CsPI has capability to specify petal development in Arabidopsis thaliana. The finding indicates that the activity of the encoded PI-like proteins is highly conserved between the early-diverging Chloranthus and Arabidopsis. Moreover, our results appear to suggest that B-function genes may not play a role in perianth development in Chloranthus spicatus.Electronic supplementary materialThe online version of this article (doi:10.1186/1999-3110-55-21) contains supplementary material, which is available to authorized users.

Highlights

In the floral ABC model, B-class genes comprised of DEFICIENS (DEF)/APETALA3 (AP3) and GLOBOSA (GLO)/PISTILLATA (PI) had been proposed to involve in second and third whorl floral organ development
Functions of these genes have been summarized in the ABCDE model, which holds that different A, B, C, D and E class MADS-domain proteins interact to form functional “ternary” or “quartet” protein complexes that are responsible for establishing the various floral organ identities
Expression patterns of CsPI in C. spicatus In order to get a clue about the function of CsPI, mRNA accumulation was analyzed by quantitative real-time PCR

Summary

Introduction

In the floral ABC model, B-class genes comprised of DEFICIENS (DEF)/APETALA3 (AP3) and GLOBOSA (GLO)/PISTILLATA (PI) had been proposed to involve in second and third whorl floral organ development. MADS-box genes are of particular interest because of the large size of the family and the critical developmental roles the members are known to play (Theissen et al 2000). In the model plant Arabidopsis thaliana, five classes of MADS-box genes were involved in determing the development of floral organ identity. Numbers of MADS-box genes have already been identified in almost every group of flowering plants, including early-diverging angiosperms. These MADS-box genes involved in flower development provided convenience for further studies on the evolution of flowers. The MADS-box gene family controlling flower development in early-diverging plants gains more and more attention

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