Arabidopsis HUA ENHANCER 4 delays flowering by upregulating the MADS-box repressor genes FLC and MAF4

Abstract

The adaptive success of flowering plants is largely due to their ability to align floral production with optimal conditions. In Arabidopsis thaliana, MADS-box repressors of the FLC/MAF-clade prevent flowering under non-inductive conditions, although the role of some members is not yet clearly defined. Using a genetic strategy, we identified the KH-domain gene HEN4, previously shown to be involved in MADS-box floral homeotic gene regulation, as a modulator of flowering time. Loss-of-function hen4 mutants are early-flowering, and their response to low growth-temperature (16 °C) and day-length is altered. Interestingly, hen4 plants showed dramatic reduction of FLC and MAF4 transcripts, whereas other flowering repressors of the same clade (FLM, MAF2, MAF3, MAF5) remained unaltered. We also determined that hen4, partly due to loss of FLC, accelerates the vegetative phase-change. This report provides insight into flowering time control and highlights the potential of versatile regulators such as HEN4 to coordinate the juvenile-to-adult transition and floral timing.

Identification and characterization of MADS-box gene family in pigeonpea, their wild relatives and comparative phylogenetic analysis with grain legumes.

“…This phylogenetic tree provides us interesting information about the evolution pattern of were clustered in the same clade. Similar results were also obtained while studying MADS-box genes in apple [15].…”

“…Identification of MADS genes in other legumes including A. hypogea, C. arietinum, G. max, P. vulgare and A. thaliana revealed the presence of 89, 83, 129, 77 and 120 MADS-box genes respectively. Kumar et al [15] identified dormancy associated loci and flowering locus C gene in apple and studied their role in flowering as well dormancy associated pathway. Likewise, HUA ENHANCER 4 that delays flowering by upregulating the MADS-box repressor genes FLC and MAF4 has also been reported from these studies [14].…”

“…MADS-box genes were also divided into 13 different gene subfamilies, termed AG, AGL2, AGL6 AGL12, AGL15, AGL17, DEF, FLC, GGM13 (Bsister), GLO, SQUA, SVP/STMADS11, and SOC1/TM3 on the basis of phylogenetic clustering [14]. Characterization of MADS genes have been carried out in many plants species including A. thaliana [15], Apple [16], Maize [17], tomato [18] and rice [19] , which has provided information regarding the evolution, conservation and function in diverse physiological and morphological traits. search for orthologs and paralogs on the similarity basis.…”

Copper deficiency alters shoot architecture and reduces fertility of both gynoecium and androecium inArabidopsis thaliana

“…8). It is also possible that copper deficiency-mediated increase in the transcript abundance of miR172 is not sufficient to promote floral induction under copper deficiency or that copper deficiency may also activate floral repressors including Flowering Locus C (FLC) (Crevillen and Dean, 2011;Ortuño-Miquel et al, 2019), which in turn, will inhibit FT expression and delay flowering, independently of miR172.…”

The Flowering Time Regulator FLK Controls Pathogen Defense in Arabidopsis thaliana

“…There are 26 KH domain proteins in Arabidopsis (Lorkovic and Barta, 2002) but only a few of them have been characterized. Like FLK, several KH domain proteins were shown to play roles in flowering control (Cheng et al, 2003; Ripoll et al, 2009; Yan et al, 2017; Ortuno-Miquel et al, 2019; Woloszynska et al, 2019). Some KH domain proteins were shown to be important for stress response, including resistance against a fungal pathogen (Thatcher et al, 2015) and abiotic stress (Chen et al, 2013; Guan et al, 2013).…”