Ectopic Expression of a WRKY Homolog from Glycine soja Alters Flowering Time in Arabidopsis

PLOS ONE, Dec 2019

Flowering is a critical event in the life cycle of plants; the WRKY-type transcription factors are reported to be involved in many developmental processes sunch as trichome development and epicuticular wax loading, but whether they are involved in flowering time regulation is still unknown. Within this study, we provide clear evidence that GsWRKY20, a member of WRKY gene family from wild soybean, is involved in controlling plant flowering time. Expression of GsWRKY20 was abundant in the shoot tips and inflorescence meristems of wild soybean. Phenotypic analysis showed that GsWRKY20 over-expression lines flowered earlier than the wild-type plants under all conditions: long-day and short-day photoperiods, vernalization, or exogenous GA3 application, indicating that GsWRKY20 may mainly be involved in an autonomous flowering pathway. Further analyses by qRT-PCR and microarray suggests that GsWRKY20 accelerating plant flowering might primarily be through the regulation of flowering-related genes (i.e., FLC, FT, SOC1 and CO) and floral meristem identity genes (i.e., AP1, SEP3, AP3, PI and AG). Our results provide the evidence demonstrating the effectiveness of manipulating GsWRKY20 for altering plant flowering time.

A PDF file should load here. If you do not see its contents the file may be temporarily unavailable at the journal website or you do not have a PDF plug-in installed and enabled in your browser.

Alternatively, you can download the file locally and open with any standalone PDF reader:

https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0073295&type=printable

Ectopic Expression of a WRKY Homolog from Glycine soja Alters Flowering Time in Arabidopsis

et al. (2013) Ectopic Expression of a WRKY Homolog from Glycine soja Alters Flowering Time in Arabidopsis. PLoS ONE 8(8): e73295. doi:10.1371/journal.pone.0073295 Ectopic Expression of a WRKY Homolog from Glycine soja Alters Flowering Time in Arabidopsis Xiao Luo 0 Xiaoli Sun 0 Baohui Liu 0 Dan Zhu 0 Xi Bai 0 Hua Cai 0 Wei Ji 0 Lei Cao 0 Jing Wu 0 Mingchao Wang 0 Xiaodong Ding 0 Yanming Zhu 0 Ji-Hong Liu, Key Laboratory of Horticultural Plant Biology (MOE), China 0 1 Plant Bioengineering Laboratory, Northeast Agricultural University , Harbin, Heilong Jiang , China , 2 Key Laboratory of Soybean Molecular Design Breeding, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences , Harbin, Heilong Jiang , China , 3 Department of Neurology, the University of Texas Southwestern Medical Center , Dallas, Texas , United States of America Flowering is a critical event in the life cycle of plants; the WRKY-type transcription factors are reported to be involved in many developmental processes sunch as trichome development and epicuticular wax loading, but whether they are involved in flowering time regulation is still unknown. Within this study, we provide clear evidence that GsWRKY20, a member of WRKY gene family from wild soybean, is involved in controlling plant flowering time. Expression of GsWRKY20 was abundant in the shoot tips and inflorescence meristems of wild soybean. Phenotypic analysis showed that GsWRKY20 over-expression lines flowered earlier than the wild-type plants under all conditions: long-day and short-day photoperiods, vernalization, or exogenous GA3 application, indicating that GsWRKY20 may mainly be involved in an autonomous flowering pathway. Further analyses by qRT-PCR and microarray suggests that GsWRKY20 accelerating plant flowering might primarily be through the regulation of flowering-related genes (i.e., FLC, FT, SOC1 and CO) and floral meristem identity genes (i.e., AP1, SEP3, AP3, PI and AG). Our results provide the evidence demonstrating the effectiveness of manipulating GsWRKY20 for altering plant flowering time. - Funding: This work was supported by the National Natural Science Foundation of China (31201223, 31171578); the Research Fund for the Doctoral Program of Higher Education of China (20102325120002); the Key Project of the Ministry of National Education (212049). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Competing interests: The authors have declared that no competing interests exist. These authors contributed equally to this work. In higher plants, a phase transition from vegetative to reproductive development is one of the most important events in their life history [1,2]. This transition is tightly coordinated through a diverse array of signaling networks that integrate various endogenous and exogenous signals [3]. Flowering time is a key trait in adaptation, as it is vital for reproductive success. Arabidopsis thaliana contains at least four flowering pathways that are responsive to these cues: the photoperiod pathway monitors changes in day length; the gibberellin pathway plays a promotive role in flowering under noninductive photoperiods; the vernalization pathway senses the prolonged exposure to low temperature; and the autonomous pathway mediates flowering by perceiving plant developmental status [35]. Most recently, an endogenous pathway that adds plant age to the control of flowering time has been described [6]. Several genes, such as CONSTANS (CO), FLOWERING LOCUS T (FT), SUPPRESSOR OF OVEREXPRESSION OF CO 1 (SOC1), and FLOWERING LOCUS C (FLC) have been identified as key components in these flowering signal pathways [3]. CO, which encodes a zinc-finger transcriptional activator, controls the timing of flowering by positively regulating two floral integrators, FT [7] and SOC1 [8]; FLC, a flowering repressor gene, also acts as an upstream regulator gene of FT and SOC1 [9]. Moreover, these flowering integrators have been shown to exhibit both overlapping and independent functions in the determination of flowering time and they integrate signals from multiple flowering pathways and their expression levels eventually determine the exact flowering time [3,10]. During the signaling of flowering regulation, a number of transcription factors (TFs) are included. MADS-domain TF family is one of the most important TF families that function in flowering regulation. Among the floral transition genes, FLC, SOC1, APETALA1 (AP1), APETALA3 (AP3), PISTILLAT (PI), AGAMOUS (AG) and SEPALLATA3 (SEP3) are members of the MADS-box gene family [11]. Furthermore, members of other transcription factor families have been identified for their role in the regulation of floral MADS-domain proteins and /or other flowering time genes directly or indirectly [11], such as NACs [12], MYBs [13], DREBs [14]. WRKY proteins are a class of DNA-binding transcriptional factors which contain one or (...truncated)


This is a preview of a remote PDF: https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0073295&type=printable

Xiao Luo, Xiaoli Sun, Baohui Liu, Dan Zhu, Xi Bai, Hua Cai, Wei Ji, Lei Cao, Jing Wu, Mingchao Wang, Xiaodong Ding, Yanming Zhu. Ectopic Expression of a WRKY Homolog from Glycine soja Alters Flowering Time in Arabidopsis, PLOS ONE, 2013, 8, DOI: 10.1371/journal.pone.0073295