Two rice MYB transcription factors maintain male fertility in response to photoperiod by modulating sugar partitioning

Photoperiod-dependent male fertility is a critical enabler of modern hybrid breeding. A MYB transcription factor, CSA, key regulator sugar partitioning in rice anthers, disruption which causes photoperiod-sensitive sterility. However, little known about the molecular mechanisms governing plant response to photoperiod. Here, we have obtained another sterile mutant, csa2, exhibits semi-sterility under long-day (LD) conditions, with normal short-day (SD) conditions. CSA2 specifically expressed and here shown be indispensable for anthers LD The protein can restore csa mutants SD conditions when CSA-specific pattern, indicating that two proteins share common downstream regulatory targets. Transcriptomic analyses also reveal discrete targets anthers. Furthermore, role transport was influenced by photoperiod during floral initiation, not simply anther development. Collectively, propose evolved at least proteins, regulate respectively. This finding provides insight into