Domestication-selected COG4-OsbZIP23 module regulates chilling tolerance in rice
S. Y. Sun, Dongfeng Liu, Wei Luo, Zhitao Li, Jinglei Feng, Ya‐Long Guo, Kang Chong, Yunyuan Xu
Abstract
<h2>Summary</h2> Identifying excellent natural variations is the foundation for breeding. Several major genes of quantitative trait loci for chilling tolerance at the seedling stage (<i>qCTS</i>) have been identified. However, less is known about the dual elite modules for the tolerance. Here, we report the major gene of <i>qCTS1-2</i>, <i>Chilling-tolerance in Geng</i>/<i>japonica rice 4</i> (<i>COG4</i>), encoding the transcription factor ENAC1, coupled with <i>OsbZIP23</i> to positively regulate chilling tolerance. The haplotype analysis and geographical distribution show that most of the chilling-tolerant <i>japonica</i> varieties carry Var9(CT) at −317 in <i>COG4</i> (<i>COG4</i><sup>jap</sup>). The <i>COG4</i><sup>jap</sup> promoter is preferentially bound by cold-induced OsbZIP23 to cause a higher expression of <i>COG4</i><sup>jap</sup> compared to <i>COG4</i><sup>ind</sup>, which promotes multiple pathways for the tolerance. Both <i>COG4</i><sup>jap</sup> and <i>OsbZIP23</i><sup>jap</sup> are artificially selected and retained in <i>japonica</i> varieties during domestication. These results not only reveal the regulatory mechanism of <i>OsbZIP23</i><sup>jap</sup>-<i>COG4</i><sup>jap</sup> module but also provide valuable variations for molecular design breeding.