College of Agronomy, National Key Laboratory of wheat and Maize Crop Science, Henan Agricultural University, Zhengzhou, China.
Crop Research Institute, Peanut Research Laboratory, Anhui Academy of Agricultural Sciences, Hefei, China.
PLoS One. 2019 Jan 30;14(1):e0211623. doi: 10.1371/journal.pone.0211623. eCollection 2019.
The circadian clock regulates numerous biological processes in plants, especially development and stress responses. CIRCADIAN CLOCK-ASSOCIATED 1 (CCA1) is one of the core components of the day-night rhythm response and is reportedly associated with ambient temperature in Arabidopsis thaliana. However, it remains unknown if alternative splicing of ZmCCA1 is modulated by external stress in maize, such as drought stress and photoperiod. Here, we identified three ZmCCA1 splice variants in the tropical maize line CML288, which are predicted to encode three different protein isoforms, i.e., ZmCCA1.1, ZmCCA1.2, and ZmCCA1.3, which all retain the MYB domain. In maize, the expression levels of ZmCCA1 splice variants were influenced by photoperiod, tissue type, and drought stress. In transgenic A. thaliana, ZmCCA1.1 may be more effective than ZmCCA1.3 in increasing drought tolerance while ZmCCA1.2 may have only a small effect on tolerance to drought stress. Additionally, although CCA1 genes have been found in many plant species, alternative CCA1 splicing events are known to occur in species-specific ways. Our study provides new sight to explore the function of ZmCCA1 splice variants' response to abiotic stress, and clarify the linkage between circadian clock and environmental stress in maize.
生物钟调节植物中的许多生物过程，特别是发育和应激反应。CIRCADIAN CLOCK-ASSOCIATED 1（CCA1）是昼夜节律反应的核心组成部分之一，据报道与拟南芥中的环境温度有关。然而，尚不清楚玉米中的 ZmCCA1 是否通过外部胁迫（如干旱胁迫和光周期）进行选择性剪接。在这里，我们在热带玉米品系 CML288 中鉴定出三个 ZmCCA1 剪接变体，它们预计编码三种不同的蛋白质同工型，即 ZmCCA1.1、ZmCCA1.2 和 ZmCCA1.3，它们都保留了 MYB 结构域。在玉米中，ZmCCA1 剪接变体的表达水平受光周期、组织类型和干旱胁迫的影响。在转基因拟南芥中，ZmCCA1.1 可能比 ZmCCA1.3 更有效地提高耐旱性，而 ZmCCA1.2 可能对耐旱性的影响较小。此外，尽管在许多植物物种中发现了 CCA1 基因，但已知在特定物种中会发生选择性 CCA1 剪接事件。我们的研究为探索 ZmCCA1 剪接变体对非生物胁迫的反应功能提供了新的视角，并阐明了玉米中生物钟和环境胁迫之间的联系。
