ANAC075, a putative regulator of VASCULAR-RELATED NAC-DOMAIN7, is a repressor of flowering

Abstract

Fine-tuning of flowering timing is crucial for plants to survive and leave offspring and depends on various endogenous and environmental factors. Here we report the identification of a vascular transcription factor, ANAC075, a putative regulator of VASCULAR-RELATED NAC-DOMAIN7 (VND7), as a negative regulator of flowering in Arabidopsis. Loss of function of ANAC075 causes the upregulation of floral integrator genes and early flowering under both long-and short-day conditions. ANAC075 promoter activity was detected in vascular tissues, including phloem. Previous reports suggested that ANAC075 is a transcriptional activator involved in the secondary cell wall formation, implying that the promotion of flowering time in anac075 mutants is caused by the disruption of flowering-time gene regulation in phloem and/or vascular tissue formation.

Genomic insights into the origin, domestication and genetic basis of agronomic traits of castor bean

“…These regions contained 1220 genes (Additional file 2 : Table S13) with functions relating to binding, metabolic process, cellular process, biological regulation, localization, and response to stimulus (Additional file 2 : Table S14). Many well-studied genes involved in the regulation of flowering, cell wall synthesis, and adaptation were identified, such as Rc10G022330 encoding a putative orthologue of TERMINAL FLOWER 1 (TFL1) that plays a critical role in the regulation of inflorescence meristem identity, flowering time, and plant height in Arabidopsis [ 32 , 33 ]; Rc03G005883 encoding a putative SNW/SKI-interacting protein (SKIP) that involved into the regulation of environmental fitness and floral transition in Arabidopsis [ 34 ]; Rc03G005826 encoding a NAC transcription factor, homologous to Arabidopsis ANAC075 that functions as a repressor of flowering and involved in secondary cell wall formation [ 35 , 36 ]; Rc04G007260 encoding a member of the R2R3 gene family (MYB46), which involved in the control of secondary cell wall thickening [ 37 ]; Rc05G010832 encoding a gibberellin 2-oxidase (GA2OX2) which had a functional role in the control of plant growth and height by regulating GA concentrations in aspen trees [ 38 ]; and two genes, Rc02G003752 and Rc02G003753, putatively encoding gibberellin-regulated proteins (Additional file 2 : Table S13).

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Xylem vessel‐specific SND5 and its homologs regulate secondary wall biosynthesis through activating secondary wall NAC binding elements

“…1a; Zhong et al ., 2011b). Although expression of SND4/ANAC075 fused with the VP16 activation domain in nst1/3 fiber cells was able to reinstate their secondary wall thickening (Sakamoto & Mitsuda, 2015), a recent study concluded that SND4/ANAC075 was not involved in secondary wall formation and instead, it was a negative regulator of flowering based on the findings that the GUS reporter gene driven by its promoter was mainly expressed in the phloem and its mutation resulted in early flowering but no phenotypes associated with secondary walls (Fujiwara & Mitsuda, 2016). Since the promoter of SND4/ANAC075 used in that study may not encompass all the cis‐elements dictating its bona fide expression, we set out to re‐examine its expression pattern.…”

“…While the function of ANAC099 has not yet been studied, ANAC075 was shown to activate the VND7 promoter (Endo et al ., 2015) and expression of VP16‐fused ANAC075 in nst1/3 fiber cells was able to reinstate their secondary wall thickening (Sakamoto & Mitsuda, 2015). However, one study reported that the ANAC075 gene was mainly expressed in the phloem and suggested that it was not involved in secondary wall formation (Fujiwara & Mitsuda, 2016). Although it is uncertain whether ANAC075 plays a role in regulating secondary wall biosynthesis, it has been shown that its poplar orthologs, PtrNAC150 and PtrNAC151, are wood‐associated, PtrWND2B‐regulated transcription factors that can activate the promoters of several biosynthesis genes for secondary wall cellulose, xylan and lignin (Zhong et al ., 2011b).…”

Transcriptional Regulation of Sorghum Stem Composition: Key Players Identified Through Co-expression Gene Network and Comparative Genomics Analyses

“…There are one additional NAC gene and one additional MYB gene in the top 10 genes of the pink module but they are not annotated with the TF GO term. Sobic.003G035100 (SbNAC75a) is a close homolog of NAC075, a putative regulator of VASCULAR RELATED NAC-DOMAIN PROTEIN 7 (VND7, Supplementary Figure S4B) which is a master regulator of vessel SCW deposition in Arabidopsis (Endo et al, 2015;Fujiwara and Mitsuda, 2016). Sobic.001G110900 is a homolog of AtMYB52/54, another regulator of SCW (Zhong et al, 2008).…”