A barleyPHDfinger transcription factor that confers male sterility by affecting tapetal development

Abstract

SummaryControlling pollen development is of major commercial importance in generating hybrid crops and selective breeding, but characterized genes for male sterility in crops are rare, with no current examples in barley. However, translation of knowledge from model species is now providing opportunities to understand and manipulate such processes in economically important crops. We have used information from regulatory networks in Arabidopsis to identify and functionally characterize a barley PHD transcription factor MALE STERTILITY1 (MS1), which expresses in the anther tapetum and plays a critical role during pollen development. Comparative analysis of Arabidopsis, rice and Brachypodium genomes was used to identify conserved regions in MS1 for primer design to amplify the barley MS1 gene; RACE-PCR was subsequently used to generate the full-length sequence. This gene shows anther-specific tapetal expression, between late tetrad stage and early microspore release. HvMS1 silencing and overexpression in barley resulted in male sterility. Additionally, HvMS1 cDNA, controlled by the native Arabidopsis MS1 promoter, successfully complemented the homozygous ms1 Arabidopsis mutant. These results confirm the conservation of MS1 function in higher plants and in particular in temperate cereals. This has provided the first example of a characterized male sterility gene in barley, which presents a valuable tool for the future control of male fertility in barley for hybrid development.

Doubled Haploid ‘CUDH2107’ as a Reference for Bulb Onion (Allium cepa L.) Research: Development of a Transcriptome Catalogue and Identification of Transcripts Associated with Male Fertility

“…MALE MEIOCYTE DEATH1 ( MMD1 ) is another PHD protein involved in the regulation of gene expression during meiosis mutations [51]. Mutations in these genes results in complete male sterility in Arabidopsis , rice and barley [51, 77–80]. In the bulb onion transcriptome dataset we found two contigs having characteristic PHD domains encoding PERSISTANT TAPETAL CELL1 ( PTC1 ) and MALE MEIOCYTE DEATH1 ( MMD1 ).…”

Construction of a multicontrol sterility system for a maize male‐sterile line and hybrid seed production based on the ZmMs7 gene encoding a PHD‐finger transcription factor

“…Therefore, a mutation generated artificially in orthologous genes ( Sb02 g026200 , BAK05033 and XP_013740694 , Figure ) may also cause male sterility. Recently, MALE STERILITY1 ( HvMS1 ), the ortholog of Arabidopsis MS1 and rice PTC1, has been isolated using RACE‐PCR and subsequent functional testing using RNAi lines in barley (Fernández Gómez and Wilson, ). Thus, a reverse genetic approach could be adopted using targeted mutagenesis technologies such as the programmable DNA endonuclease and CRISPR/Cas9 system (Cigan et al ., ; Gomez et al ., ; Svitashev et al ., ), which will lead to site‐specific mutations in the corresponding orthologs of ZmMs7 and produce male‐sterile mutants in these crops.…”

Tightly Controlled Expression of bHLH142 Is Essential for Timely Tapetal Programmed Cell Death and Pollen Development in Rice

“…Moreover, overexpressing MS1 as driven by the CaMV35S promoter also caused stunted plants with sterile pollen in Arabidopsis (Yang et al, 2007). Recently, the ortholog of MS1 in barley ( HvMS1 ) was cloned and its expression was altered to be either overexpressed or suppressed, both RNAi and overexpression of HvMS1 full-length cDNA under the control of the maize ubiquitin promoter caused male sterile phenotype in the transgenic barley plants (Fernandez Gomez and Wilson, 2014). Also, knockout of AtCEP1 , which encodes a papain-like cysteine protease involved in tapetal PCD, delayed tapetal PCD, while its overexpression caused premature tapetal PCD (Zhang et al, 2014).…”