**Genome-Wide Analysis of** *LIM* **Family Genes in Foxtail Millet (***Setaria italica* **L.) and Characterization of the Role of** *SiWLIM2b* **in Drought Tolerance**

**Rui Yang 1,2,†, Ming Chen 2,†, Jian-Chang Sun 3,†, Yue Yu 1,2, Dong-Hong Min <sup>1</sup> , Jun Chen <sup>2</sup> , Zhao-Shi Xu <sup>2</sup> , Yong-Bin Zhou <sup>2</sup> , You-Zhi Ma 2,\* and Xiao-Hong Zhang 1,\***


Received: 23 January 2019; Accepted: 11 March 2019; Published: 15 March 2019

**Abstract:** LIM proteins have been found to play important roles in many life activities, including the regulation of gene expression, construction of the cytoskeleton, signal transduction and metabolic regulation. Because of their important roles in many aspects of plant development, *LIM* genes have been studied in many plant species. However, the *LIM* gene family has not yet been characterized in foxtail millet. In this study, we analyzed the whole genome of foxtail millet and identified 10 *LIM* genes. All *LIM* gene promoters contain MYB and MYC *cis*-acting elements that are related to drought stress. Based on the presence of multiple abiotic stress-related *cis*-elements in the promoter of *SiWLIM2b*, we chose this gene for further study. We analyzed *SiWLIM2b* expression under abiotic stress and hormone treatments using qRT-PCR. We found that *SiWLIM2b* was induced by various abiotic stresses and hormones. Under drought conditions, transgenic rice of *SiWLIM2b*-overexpression had a higher survival rate, higher relative water content and less cell damage than wild type (WT) rice. These results indicate that overexpression of the foxtail millet *SiWLIM2b* gene enhances drought tolerance in transgenic rice, and the *SiWLIM2b* gene can potentially be used for molecular breeding of crops with increased resistance to abiotic stress.

**Keywords:** genome-wide analysis; drought tolerance; foxtail millet; *LIM* genes; transgenic rice
