Suppression and restoration of male fertility using a transcription factor

Abstract

SummaryThe Arabidopsis AtMYB103 gene codes for an R2R3 MYB domain protein whose expression is restricted to the tapetum of developing anthers and to trichomes. Down-regulation of expression using anti-sense leads to abnormal tapetum and pollen development, although restorer constitute a reversible male sterility system which could be adapted for hybrid seed production. This is the first reversible male sterility system targeting a transcription factor essential for pollen development. Strategies for generating inducible male sterility and maintainable male sterility for the production of hybrid crops are discussed.

The MYB80 Transcription Factor Is Required for Pollen Development and the Regulation of Tapetal Programmed Cell Death inArabidopsis thaliana

“…This construct was transformed into myb80 mutant plants. Following application of dexamethasone (DEX), the AtMYB80:GR fusion protein is able to enter the nucleus, resulting in complete restoration of male fertility (Li et al, 2007). Comparison of gene expression levels just prior to and following application of DEX was expected to enable identification of MYB80 target genes.…”

“…MYB80 expression is clearly detected in the tapetum and microspores of anthers containing tetrads (stage 7), and expression persists until stage 10 when the tapetum begins to degenerate (Higginson et al, 2003;Li et al, 2007). Functional disruption of MYB80 using antisense (Higginson et al, 2003), T-DNA knockout (Li et al, 2007), or point mutation (Zhang et al, 2007) resulted in a partial (in the case of the antisense lines) or complete male sterility. The myb80 mutant exhibits signs of premature tapetal degeneration in stage 6 anthers, which becomes more pronounced at stage 7, where an increase in tapetal vacuolation occurs.…”

“…MYB80 expression is absent in stage 11 anthers (Higginson et al, 2003;Li et al, 2007). Promoter:GUS (b-glucuronidase) constructs were created, and quantitative RT-PCR (qRT-PCR) analysis was performed to detect transcript levels of the three target genes and MYB80 (see Supplemental Figure 6 online) in young floral buds (corresponding with anther stages 9 and below) and mature floral buds (anther stages 10 to 12).…”

“…Transcription factors known to be involved in tapetal development include DYSFUNCTIONAL TAPETUM1 (DYT1) (Zhang et al, 2006), MYB33/MYB65 (Millar and Gubler, 2005), DEFECTIVE IN TAPETAL DEVELOPMENT AND FUNCTION1 (TDF1) (Zhu et al, 2008), ABORTED MICROSPORES (AMS) (Sorensen et al, 2003), MALE STERILITY1 (MS1) (Wilson et al, 2001;Ito and Shinozaki, 2002) and MYB80 (formerly MYB103) (Higginson et al, 2003;Li et al, 2007;Zhang et al, 2007). DYT1 and AMS both encode basic-helix-loop-helix proteins, whereas TDF1 and MS1 encode MYB and PHD transcription factors, respectively.…”

The Rice Basic Helix-Loop-Helix Transcription Factor TDR INTERACTING PROTEIN2 Is a Central Switch in Early Anther Development

“…Premature or retarded tapetal degeneration frequently causes male sterility (N. Li et al, 2007;Zhang et al, 2007;Shi et al, 2009;Phan et al, 2011). Genetic investigations discovered several transcription factors involved in rice tapetal degeneration, such as GAMYB (Kaneko et al, 2004;Liu et al, 2010), TDR (N. , EAT1 (Niu et al, 2013), and Os-API5 (X.…”