Table_2_Genome-Wide Analysis of MADS-Box Genes in Foxtail Millet (Setaria italica L.) and Functional Assessment of the Role of SiMADS51 in the Drought Stress Response.XLSX

MADS-box transcription factors play vital roles in multiple biological processes in plants. At present, a comprehensive investigation into the genome-wide identification and classification of MADS-box genes in foxtail millet (Setaria italica L.) has not been reported. In this study, we identified 72 MADS-box genes in the foxtail millet genome and give an overview of the phylogeny, chromosomal location, gene structures, and potential functions of the proteins encoded by these genes. We also found that the expression of 10 MIKC-type MADS-box genes was induced by abiotic stresses (PEG-6000 and NaCl) and exogenous hormones (ABA and GA), which suggests that these genes may play important regulatory roles in response to different stresses. Further studies showed that transgenic Arabidopsis and rice (Oryza sativa L.) plants overexpressing SiMADS51 had reduced drought stress tolerance as revealed by lower survival rates and poorer growth performance under drought stress conditions, which demonstrated that SiMADS51 is a negative regulator of drought stress tolerance in plants. Moreover, expression of some stress-related genes were down-regulated in the SiMADS51-overexpressing plants. The results of our study provide an overall picture of the MADS-box gene family in foxtail millet and establish a foundation for further research on the mechanisms of action of MADS-box proteins with respect to abiotic stresses.

MADS-box转录因子（MADS-box transcription factors）在植物的多种生物学过程中发挥至关重要的调控作用。目前，针对谷子（Setaria italica L.）全基因组范围内MADS-box基因的鉴定与分类的系统性研究尚未见报道。本研究在谷子基因组中鉴定得到72个MADS-box基因，并对这些基因编码蛋白的系统发育、染色体定位、基因结构及潜在功能进行了全面概述。研究还发现，10个MIKC型MADS-box基因的表达可被非生物胁迫（PEG-6000与NaCl）及外源激素（脱落酸ABA、赤霉素GA）诱导，提示这些基因可能在响应不同胁迫的过程中发挥重要调控作用。进一步研究显示，过表达SiMADS51的转基因拟南芥与水稻（Oryza sativa L.）植株在干旱胁迫条件下存活率更低、生长状态更差，表现出减弱的干旱胁迫耐受性，这证实SiMADS51是植物干旱胁迫耐受性的负调控因子。此外，在过表达SiMADS51的转基因植株中，部分胁迫相关基因的表达量出现下调。本研究的结果全面呈现了谷子MADS-box基因家族的整体特征，为后续探究MADS-box蛋白参与非生物胁迫的作用机制奠定了坚实的研究基础。