This Valentines Day weekend the Wagner Lab welcomed the newest member of our lab, Dr. Sandhan Prakash, to the City of Brotherly Love! Dr. Prakash flew all the way from the Indian Institute of Science (IISc) in Bangalore, India where he received his Ph.D. In the Wagner Lab, he plans to study the function of epigenomic regulators in cell fate reprogramming and plant survival mechanism during abiotic stress response.
The Wagner Lab’s most recent publication uncovers the role of a protein called “LFY” in Arabidopsis chromatin regulation. A news release on the publication was covered by the American Association for the Advancement of Science (AAAS). To see the article click here.
Jin, J., Klasfeld, S., Zhu, Y., Fernandez Garcia, M., Xiao, J., Han, S.K., Konkol, A., Zhu, Y. & Wagner, D. (2021). LEAFY is a pioneer transcription factor and licenses cell reprogramming to floral fate. Nature Communications, 12(1), 626.
Master transcription factors reprogram cell fate in multicellular eukaryotes. Pioneer transcription factors have prominent roles in this process because of their ability to contact their cognate binding motifs in closed chromatin. Reprogramming is pervasive in plants, whose development is plastic and tuned by the environment, yet little is known about pioneer transcription factors in this kingdom. Here, we show that the master transcription factor LEAFY (LFY), which promotes floral fate through upregulation of the floral commitment factor APETALA1 (AP1), is a pioneer transcription factor. In vitro, LFY binds to the endogenous AP1 target locus DNA assembled into a nucleosome. In vivo, LFY associates with nucleosome occupied binding sites at the majority of its target loci, including AP1. Upon binding, LFY ‘unlocks’ chromatin locally by displacing the H1 linker histone and by recruiting SWI/SNF chromatin remodelers, but broad changes in chromatin accessibility occur later. Our study provides a mechanistic framework for patterning of inflorescence architecture and uncovers striking similarities between LFY and animal pioneer transcription factor.
Zhu, Y., Klasfeld, S., & Wagner, D. (2021). Molecular regulation of plant developmental transitions and plant architecture via PEPB family proteins–an update on mechanism of action. Journal of Experimental Botany, eraa598
This year marks the 100 th anniversary of the experiments by Garner and Allard (Garner and Allard, 1920) that showed that plants measure the duration of the night and day (the photoperiod) to time flowering. This discovery led to the identification of Flowering Locus T (FT) in Arabidopsis and Heading Date 3a (Hd3a) in rice as a mobile signal that promotes flowering in tissues distal to the site of cue perception. FT/Hd3a belong to the family of phosphatidylethanolamine binding proteins (PEBPs). Collectively, these proteins control plant developmental transitions and plant architecture. Several excellent recent reviews have focused on the roles of PEBP proteins in diverse plant species; here we will primarily highlight recent advances that enhance our understanding of the mechanism of action of PEBP proteins and discuss critical open questions.
In the mist of the USA elections, the Wagner Lab is over joyed to welcome Dr. Shalini Yadav. Dr. Yadav traveled all the way from the Indian Institute of Science Education and Research (IISER) in Mohali, India where she received her Ph.D. In the Wagner Lab she plans to study the role of antiflorigen Terminal Flower (TFL1) in axillary meristem fate.
Zhu, Y., Klasfeld, S., Jeong, C.W., Jin, R., Goto, K., Yamaguchi, N., & Wagner, D.(2020). TERMINAL FLOWER 1-FD complex target genes and competition with FLOWERING LOCUS T. Nature Communications, 11(2), 5118.
Plants monitor seasonal cues to optimize reproductive success by tuning onset of reproduction and inflorescence architecture. TERMINAL FLOWER 1 (TFL1) and FLOWERING LOCUS T (FT) and their orthologs antagonistically regulate these life history traits, yet their mechanism of action, antagonism and targets remain poorly understood. Here, we show that TFL1 is recruited to thousands of loci by the bZIP transcription factor FD. We identify the master regulator of floral fate, LEAFY (LFY) as a target under dual opposite regulation by TFL1 and FT and uncover a pivotal role of FT in promoting flower fate via LFY upregulation. We provide evidence that the antagonism between FT and TFL1 relies on competition for chromatin-bound FD at shared target loci. Direct TFL1-FD regulated target genes identify this complex as a hub for repressing both master regulators of reproductive development and endogenous signalling pathways. Our data provide mechanistic insight into how TFL1-FD sculpt inflorescence architecture, a trait important for reproductive success, plant architecture and yield.
Welcome Tian Huang! Tian did his undergraduate studies in Fudan University, in Shanghai, China and now he is sharing his enthusiasm for plant research as a member of the Biology Graduate Program. We are so excited that he chose to join our lab and look forward to the discoveries we will make together.
Communication in science is of utmost importance for scientific advancement. Science Advances is an online-only gold open access journal from American Association for the Advancement of Science (AAAS), the publisher of Science. Debuty Editor, Dr. Elizabeth Haswell, is heading up a brand new editorial pod dedicated to plant biology and she chose fantastic editors including Dr. Doris Wagner of the Wagner Lab. Others on the team include Dr. John McDowell, Dr. Mary Lou Guerinot, Dr. Thorsten Hamann, Dr. Keiko Sugimoto, Dr. Elizabeth Kellogg, and Dr. Sarah O’Connor.