Heat shock stress causes alteration in the physiological and molecular characteristics in plants due to the generation of reactive oxygen species which cause reduction in plant growth. In this study, four maize hybrids (Sc122, TWC 321, TWC 324 and TWC 352) were grown under normal temperature (25 °C) and after 12 days, a set of the four hybrids with three replicates was exposed to heat shock (45 °C) for 2 h. The results showed on the one hand that heat shock stress caused an increment in phytohormones (auxin, gibberellic acid and zeatin) except abscisic acid in two maize hybrids (Sc122 and TWC 321). On the other hand, all the parameters mentioned above were decreased significantly in the other maize hybrids (TWC 324 and TWC 352). In addition, osmolytes (proline and glycine betaine), polyamines (spermidine, putrescine, and spermine) and total soluble sugars were significantly increased in all maize hybrids but the most pronounced increases were recorded in the two maize hybrids Sc122 and TWC 321. These results confirm a previous study that the maize hybrids Sc122 and TWC 321 are considered as tolerant genotypes and the other two hybrids (TWC 324 and TWC 352) as sensitive genotypes. Differential gene expression under normal and heat shock conditions were adopted to search for some heat responsive genes in Egyptian maize hybrids. Three out of the five designed primers produced fragments. Alignment analysis revealed resemblance of the resulted fragments and some heat responsive genes in different species.

中文翻译：

---

玉米杂种热激胁迫的生理生化效应及耐热性相关分子标记的测定

由于产生活性氧，导致植物生长减少，热激胁迫导致植物的生理和分子特性发生变化。在这项研究中，四个玉米杂种（Sc122，TWC 321，TWC 324和TWC 352）在常温（25°C）下生长，并且在12天后，四个具有三个重复的四个杂种中的一组暴露于热激下（45）。 °C）2小时。结果表明，一方面，热休克胁迫导致两种玉米杂种（Sc122和TWC 321）中除脱落酸外的植物激素（生长素，赤霉素和玉米素）增加。另一方面，在所有其他玉米杂交种（TWC 324和TWC 352）中，上述所有参数均显着降低。此外，渗透剂（脯氨酸和甘氨酸甜菜碱），多胺（亚精胺，腐胺，和精胺）和总可溶性糖在所有玉米杂种中均显着增加，但在两个玉米杂种Sc122和TWC 321中记录到最明显的增加。这些结果证实了先前的研究，即玉米杂种Sc122和TWC 321被认为是耐性基因型和其他两个杂种（TWC 324和TWC 352）作为敏感基因型。通过在正常和热激条件下的差异基因表达来寻找埃及玉米杂交种中的一些热响应基因。五种设计引物中有三种产生了片段。比对分析揭示了所得片段和不同物种中一些热响应基因的相似性。这些结果证实了先前的研究，即玉米杂交体Sc122和TWC 321被认为是耐性基因型，而其他两个杂交体（TWC 324和TWC 352）被认为是敏感基因型。通过在正常和热激条件下的差异基因表达来寻找埃及玉米杂交种中的一些热响应基因。五种设计引物中有三种产生了片段。比对分析揭示了所得片段和不同物种中一些热响应基因的相似性。这些结果证实了先前的研究，即玉米杂交体Sc122和TWC 321被认为是耐性基因型，而其他两个杂交体（TWC 324和TWC 352）被认为是敏感基因型。通过在正常和热激条件下的差异基因表达来寻找埃及玉米杂交种中的一些热响应基因。五种设计引物中有三种产生了片段。比对分析揭示了所得片段和不同物种中一些热响应基因的相似性。五种设计引物中有三种产生了片段。比对分析揭示了所得片段和不同物种中一些热响应基因的相似性。五种设计引物中有三种产生了片段。比对分析揭示了所得片段和不同物种中一些热响应基因的相似性。