Analysis of early-flowering genes at barley chromosome 2H expands the repertoire of mutant alleles at the Mat-c locus

Izabela Matyszczak,Marta Tominska,Shakhira Zakhrabekova,Mats Hansson,Christoph Dockter

doi:10.1007/s00299-019-02472-4

Izabela Matyszczak, Marta Tominska + Show 3 more

Open Access

https://doi.org/10.1007/s00299-019-02472-4

Copy DOI

Abstract

Key messageAnalyses of barley mat-c loss of function mutants reveal deletions, splice-site mutations and nonsynonymous substitutions in a key gene regulating early flowering.Optimal timing of flowering is critical for reproductive success and crop yield improvement. Several major quantitative trait loci for flowering time variation have been identified in barley. In the present study, we analyzed two near-isogenic lines, BW507 and BW508, which were reported to carry two independent early-flowering mutant loci, mat-b.7 and mat-c.19, respectively. Both introgression segments are co-localized in the pericentromeric region of chromosome 2H. We mapped the mutation in BW507 to a 31 Mbp interval on chromosome 2HL and concluded that BW507 has a deletion of Mat-c, which is an ortholog of Antirrhinum majus CENTRORADIALIS (AmCEN) and Arabidopsis thaliana TERMINAL FLOWER1 (AtTFL1). Contrary to previous reports, our data showed that both BW507 and BW508 are Mat-c deficient and none of them are mat-b.7 derived. This work complements previous studies by identifying the uncharacterized mat-c.19 mutant and seven additional mat-c mutants. Moreover, we explored the X-ray structure of AtTFL1 for prediction of the functional effects of nonsynonymous substitutions caused by mutations in Mat-c.

Highlights

Floral induction is the change from vegetative to reproductive growth, a key event in the life cycle of flowering plants
FLOWERING LOCUS T (FT) encodes a mobile protein that moves from leaves to the shoot apical meristem (SAM) (Corbesier et al 2007; Jaeger and Wigge 2007; Tamaki et al 2007) where it creates a complex with the basic leucine zipper transcription factor, FLOWERING LOCUS D (FD), to activate expression of floral meristem identity genes such as APETALA1 (AP1) in Arabidopsis (Abe et al 2005; Wigge et al 2005), VERNALIZATION1 (VRN1) in wheat (Triticum aestivum L.) (Li and Dubcovsky 2008) and FRUITFULL2 (FUL2) in rice (Oryza sativa) (Tsuji et al 2011)
Phenotypic effects of the mat-b and mat-c mutant loci were investigated using original mat-b.7 and mat-c.19 mutants induced in Bonus, and the respective Bowman introgression lines BW507 and BW508, grown in parallel with parental cultivars

Summary

Introduction

Floral induction is the change from vegetative to reproductive growth, a key event in the life cycle of flowering plants. Plant Cell Reports (2020) 39:47–61 as a candidate underlying a QTL (Quantitative Trait Locus) that contributed to the differentiation of winter and spring barley growth habit (Comadran et al 2012). FT encodes a mobile protein (florigen) that moves from leaves to the shoot apical meristem (SAM) (Corbesier et al 2007; Jaeger and Wigge 2007; Tamaki et al 2007) where it creates a complex with the basic leucine zipper (bZIP) transcription factor, FLOWERING LOCUS D (FD), to activate expression of floral meristem identity genes such as APETALA1 (AP1) in Arabidopsis (Abe et al 2005; Wigge et al 2005), VERNALIZATION1 (VRN1) in wheat (Triticum aestivum L.) (Li and Dubcovsky 2008) and FRUITFULL2 (FUL2) in rice (Oryza sativa) (Tsuji et al 2011). The expression of meristem identity genes in Arabidopsis is antagonized by TFL1 activity through a TFL1-FD complex which inhibits the switch to reproductive growth (Hanano and Goto 2011)

Methods

Results

Conclusion