Ectopic expression of a Brassica rapa AINTEGUMENTA gene (BrANT-1) increases organ size and stomatal density in Arabidopsis

Qian Ding,Nianwei Qiu,Jingjuan Li,Jianwei Gao,Fengde Wang,Yihui Zhang,Bing Cui,Huayin Li,Xiaohui Lv,Lifeng Liu

doi:10.1038/s41598-018-28606-4

Abstract

The AINTEGUMENTA-like (AIL) family plays a central role in regulating the growth and development of organs in many plants. However, little is known about the characteristics and functions of the AIL family in Chinese cabbage (Brassica rapa L. ssp. pekinensis). In this study, a genome-wide analysis was performed to identify the members of the AIL family in Chinese cabbage. We identified three ANT genes and six ANT-like genes of Chinese cabbage, most of which were differentially expressed in different organs or tissues. Furthermore, compared with the wild-type line, the size of different organs in the 35S-BrANT-1 line was significantly increased by promoting cell proliferation. Meanwhile, over-expression of BrANT-1 also increases the stomatal number and delays the leaf senescence. Transcriptome analyses revealed that a set of cell proliferation and stoma development genes were up-regulated, while the senescence-associated genes were down-regulated, suggesting these genes may be involved in BrANT-1 regulated processes for controlling organ size, stomatal density and leaf senescence. In summary, this study offers important insights into the characteristics and functions of the ANT genes in Chinese cabbage, and provides a promising strategy to improve yield or head size in Chinese cabbage breeding programs.

Highlights

The size of the leafy head is an important economical trait of Chinese cabbage (Brassica rapa L. ssp. pekinensis)
A total of nine BrAIL family members were identified in the Chinese cabbage genome, according to the taxonomy of the AP2 superfamily (Supplementary Tables S1 and S2)
When more than two Chinese cabbage genes were mapped to one homologous gene in A. thaliana, one additional number was added to the end of the gene name[21]

Summary

Introduction

The size of the leafy head is an important economical trait of Chinese cabbage (Brassica rapa L. ssp. pekinensis). Many studies revealed that ANT regulates organ size by changing the total cell numbers[7]. Cells ectopically expressing ANT in fully differentiated organs exhibit neoplastic activity by producing calli and adventitious roots and shoots[7]. These studies strongly suggest that ANT most likely maintains ongoing cell proliferation coordinately with cell growth[19]. We investigated the BrAIL family members in Chinese cabbage through genome-wide bioinformatics analysis, including the identification and characterization of the AIL family members, gene structural analysis, phylogeny and motif analysis. By analyzing the potential pathways where BrANT-1 participates, it is possible to understand how the gene regulates Chinese cabbage yield and/or head size

Methods

Results

Conclusion