盐害严重威胁着植物的生长和发育。因此，识别和筛选盐胁迫响应的关键基因并解析其作用机制对提高植物的耐盐性至关重要。本研究运用磷酸化蛋白质组技术对盐胁迫处理前后的谷子样品进行检测分析，共鉴定出4000个磷酸化多肽，其中123个显著差异。非冗余蛋白质数据库（NR）功能注释显示，有23个转录因子表达差异显著，如SiRAV1转录因子。亚细胞定位分析显示SiRAV1位于细胞核中。表型和生理分析证实，SiRAV1的过表达能够提高谷子对盐胁迫的耐受性，且这一作用是通过抑制盐诱导的H₂O₂积累、丙二醛含量和电解质渗漏率的增加等方式实现的。进一步的研究表明，SiRAV1能够直接结合SiCAT启动子以激活SiCAT的表达，从而提高CAT酶的活性。本研究还发现，SiRAV1蛋白的Ser31位点磷酸化可以通过增强其与SiCAT启动子的结合能力来正向调节谷子的耐盐性。综上所述，本研究首次解析了SiRAV1在谷子盐响应中的作用机制：盐胁迫通过诱导SiRAV1蛋白的Ser31位点磷酸化，进而增强了其与SiCAT启动子的结合能力，激活了SiCAT的表达，从而提高谷子对盐胁迫的耐受性。

Heterosis has contributed greatly to yield in maize, but the nature of its contribution is not completely clear. In this study, two strategies using whole-genome oligonucleotide microarrays were employed to identify differentially expressed genes (DEGs) associated with heterosis and yield. The analysis revealed 1 838 heterosis-associated genes (HAGs), 265 yieldassociated genes (YAGs), and 85 yield heterosis-associated genes (YHAGs). 37.1% of HAGs and 22.4% of YHAGs expressed additively. The remaining genes expressed non-additively, including those with high/low-parent dominance and over/under dominance, which were prevalent in this research. Pathway enrichment analysis and quantitative trait locus (QTL) co-mapping demonstrated that the metabolic pathways for energy and carbohydrates were the two main enriched pathways influencing heterosis and yield. Therefore, the DEGs participating in energy and carbohydrate metabolism were considered to contribute to heterosis and yield significantly. The investigation of potential groups of HAGs, YAGs, and YHAGs might provide valuable information for exploiting heterosis to improve yield in maize breeding. In addition, our results support the view that heterosis is contributed by multiple, complex molecular mechanisms.

Heterosis plays an important role in crop production and plant evolution. Although heterosis has been widely exploited by plant breeders, the underlying molecular mechanisms are not well understood. We analyzed gene expression of the highly heterotic maize hybrid Zhengdan 958 and its parents, Zheng 58 and Chang 7-2 during spikelet and floscule differentiation using the GeneChip® Maize Genome Array. Pairwise comparison among Zhengdan 958 and its parents at the two stages of immature ear development identfied 1 089 and 1 352 differentially expressed genes. Gene ontology (GO) functional analysis showed that these genes participate in many functional categories, and those encoding response to stress and transcription factor may play important roles in heterosis. Pathway analysis showed that the differentially expressed genes are involved in various metabolic processes, and those participating in lipid metabolism, signal transduction, transport, and catabolism may contribute to heterosis. A non-additive expression pattern was prevalent in genes that were differentially expressed between the hybrid and its parents during both spikelet and floscule differentiation. Because genes that are differentially expressed in a hybrid and its parents could underlie heterosis, nonadditive expression patterns might contribute to the manifestation of heterosis.