TEOSINTE BRANCHED1/CYCLOIDEA/PROLIFERATING CELL FACTOR4 Interacts with WRINKLED1 to Mediate Seed Oil Biosynthesis

Abstract

Characterization of the TCP4-WRI1 complex regulating Arabidopsis seed oil biosynthesis expands our understanding of WRI1-interacting factors and describes a further role for TCP transcription factors.

Intrinsic Disorder in Plant Transcription Factor Systems: Functional Implications

“…To exemplify, synergistic interactions between R2R3-MYB TFs, bHLH TFs, and WD40 proteins form a MYB:bHLH:WD40 complex which regulates anthocyanin biosynthesis in a wide range of plant species [ 174 ]. Interactions between MYC2 and the bZIP TFs, G-box-binding factors (GBFs), result in functional antagonism in blue light-mediated Arabidopsis seedling development [ 175 ], and interactions between the TCP TF Os TB1 and the MADS TF Os MADS57 regulate tillering in rice [ 176 ], whereas interactions between TCP4 and WRI1 repress the transcriptional activity of WRI1 [ 177 ]. Interactions between MYB and bHLH TFs are especially common [ 72 ] and result in different phenotypic effects.…”

Unexpected Role of a TCP Transcription Factor in Seed Oil Biosynthesis

“…In this study, Kong et al (2020) uncovered the unexpected role of the TCP4 transcription factor in seed oil biosynthesis through its interaction with the master regulator WRI1, thus shedding light on the complicated regulatory network of seed oil biosynthesis. WRI1 plays a central role in seed oil production, and several posttranslational regulators have been identified to maintain the homeostasis of WRI1 (Fig.…”

“…Several interaction partners of WRI1 have been shown to regulate WRI1 proteostasis previously (in gray). TCP4 regulates oil biosynthesis by repressing the transactivation activity of WRI1, as demonstrated by Kong et al (2020;in black). The red line indicates positive regulation, and the blue lines indicate negative regulation.…”

“…In this issue of Plant Physiology, Kong et al (2020) provide new insight into WRI1 function by demonstrating that a TEOSINTE BRANCHED1/CYCLOIDEA/PRO-LIFERATING CELL FACTOR (TCP) transcription factor, TCP4, binds to WRI1 and negatively regulates seed oil biosynthesis through the repression of WRI1 transactivation activity. The authors searched for protein-protein interaction partners of WRI1 by a yeast two-hybrid screen.…”

“…A convenient and robust method to functionally validate oil biosynthesis regulators is to transiently express the regulator in Nicotiana benthamiana leaves and then examine oil accumulation (Ma et al, 2015). Kong et al (2020) tested the effects of different combinations of TCPs and WRI1 with this method. As expected, the expression of WRI1 induced oil accumulation.…”