Centre for Agricultural Research, Plant Protection Institute, ELKH, 15 Herman Ottó Str., H-1022 Budapest, Hungary.
Centre for Agricultural Research, Agricultural Institute, ELKH, 2 Brunszvik Str., H-2462 Martonvásár, Hungary.
Genes (Basel). 2021 May 19;12(5):776. doi: 10.3390/genes12050776.
Heat stress negatively affects barley production and under elevated temperatures defense responses to powdery mildew ( f. sp. Bgh) are altered. Previous research has analyzed the effects of short-term (30 s to 2 h) heat stress, however, few data are available on the influence of long-term exposure to heat on powdery mildew infections. We simultaneously assessed the effects of short and long term heat pre-exposure on resistance/susceptibility of barley to Bgh, evaluating powdery mildew infection by analyzing symptoms and Bgh biomass with RT-qPCR in barley plants pre-exposed to high temperatures (28 and 35 °C from 30 s to 5 days). Plant defense gene expression after heat stress pre-exposure and inoculation was also monitored. Our results show that prolonged heat stress (24, 48 and 120 h) further enhanced Bgh susceptibility in a susceptible barley line (MvHV118-17), while a resistant line (MvHV07-17) retained its pathogen resistance. Furthermore, prolonged heat stress significantly repressed the expression of several defense-related genes (, and ) in both resistant and susceptible barley lines. Remarkably, heat-suppressed defense gene expression returned to normal levels only in MvHV07-17, a possible reason why this barley line retains Bgh resistance even at high temperatures.
热应激会对大麦生产产生负面影响，并且在高温下，对白粉病（ f. sp. Bgh）的防御反应会发生改变。先前的研究分析了短期（30 秒至 2 小时）热应激的影响，但是，关于长期暴露于高温对白粉病感染的影响的数据很少。我们同时评估了短期和长期热预处理对大麦对 Bgh 的抗性/敏感性的影响，通过分析高温（28 和 35°C，30 秒至 5 天）预处理的大麦植株中的症状和 Bgh 生物量，评估白粉病的感染情况。还监测了热应激预处理和接种后植物防御基因的表达。我们的结果表明，长时间的热应激（24、48 和 120 小时）进一步增强了易感大麦品系（MvHV118-17）中 Bgh 的易感性，而抗性品系（MvHV07-17）则保持了对病原体的抗性。此外，长时间的热应激显著抑制了两种大麦品系（抗性和易感）中几个防御相关基因（、和）的表达。值得注意的是，只有在 MvHV07-17 中，热抑制的防御基因表达才恢复到正常水平，这可能是该大麦品系即使在高温下仍能保持对白粉病抗性的原因。
