College of Agriculture, Northeast Agricultural University, Harbin 150030, P.R. China.
Funct Plant Biol. 2018 Nov;45(12):1173-1180. doi: 10.1071/FP17356.
The ABA-stress-ripening (ASR) gene is an abiotic stress-response gene that is widely present in higher plants. The expression of ASR was recently shown to effectively improve plant tolerance to several abiotic stresses. However, the role of ASR during chilling stress in maize (Zea mays L.) is unclear. In this study, we tested two maize varieties under chilling treatment. Our results showed that Jinyu 5 (JY5), a chilling-sensitive variety, had lower maximum PSII efficiency (Fv/Fm) and higher lipid peroxidation levels than Jidan 198 (JD198) under chilling conditions. At the same time, the enzymes superoxide dismutase (SOD) and peroxidase (POD) were more active in JD198 than in JY5 under chilling conditions. In addition, exogenous ABA spray pretreatments enhanced the chilling tolerance of maize, showing results such as increased Fv/Fm ratios, and SOD and POD activity; significantly reduced lipid peroxidation levels and increased expression of ZmASR1 in both JD198 and JY5 under chilling conditions. Moreover, when the ZmASR1 expression levels in the two maize varieties were compared, the chilling-sensitive line JY5 had significantly lower expression in both the leaves and roots than JD198 under chilling stress, indicating that the expression of ZmASR1 is a chilling response option in plants. Furthermore, we overexpressed ZmASR1 in JY5; this resulted in enhanced maize chilling tolerance, which reduced the decreases in Fv/Fm and the malondialdehyde content and enhanced SOD and POD activity. Overall, these results suggest that ZmASR1 expression plays a protective role against chilling stress in plants.
ABA 胁迫成熟（ASR）基因是一种广泛存在于高等植物中的非生物胁迫响应基因。最近的研究表明，ASR 的表达可以有效提高植物对多种非生物胁迫的耐受性。然而，ASR 在玉米（Zea mays L.）冷胁迫中的作用尚不清楚。本研究在冷胁迫下对两个玉米品种进行了测试。结果表明，在冷胁迫下，敏感品种金玉 5（JY5）的最大 PSII 效率（Fv/Fm）较低，脂质过氧化水平较高，而丹 198（JD198）则相反。同时，在冷胁迫下，JD198 中的超氧化物歧化酶（SOD）和过氧化物酶（POD）活性高于 JY5。此外，外源 ABA 喷雾预处理提高了玉米的冷胁迫耐受性，表现为 Fv/Fm 比值增加，SOD 和 POD 活性增加；显著降低了脂质过氧化水平，增加了 ZmASR1 的表达。在冷胁迫下，JD198 和 JY5 中的两种玉米品种。此外，当比较两个玉米品种中 ZmASR1 的表达水平时，冷敏感系 JY5 在冷胁迫下叶片和根系中的表达均显著低于 JD198，表明 ZmASR1 的表达是植物对冷胁迫的一种响应选择。此外，我们在 JY5 中过表达了 ZmASR1；这导致玉米冷胁迫耐受性增强，降低了 Fv/Fm 和丙二醛含量的降低，增强了 SOD 和 POD 活性。总之，这些结果表明 ZmASR1 的表达在植物中对冷胁迫具有保护作用。
