Király Lóránt, Bacsó Renáta, Albert Réka, Schwarczinger Ildikó, Nagy Judit Kolozsváriné, Künstler András
Department of Plant Pathophysiology, Plant Protection Institute, HUN-REN Centre for Agricultural Research, H-1116 Budapest, Hungary.
Institute of Plant Sciences and Environmental Protection, Faculty of Agriculture, University of Szeged, H-6800 Hódmezővásárhely, Hungary.
Plants (Basel). 2025 Sep 2;14(17):2736. doi: 10.3390/plants14172736.
Our previous research has demonstrated the role of optimal temperatures and reactive oxygen species (ROS) in maintaining symptomless nonhost resistance (NHR) of barley to powdery mildews. However, the exact functions of temperature and ROS in NHR of plants, including barley, to viral infections are not known. Although barley is a nonhost for (TMV), this virus can replicate in barley leaves at temperatures of ca. 30 °C. Here we elucidated the influence of short-term heat stress pre-treatments (30 °C, 3 h; heat shock at 49 °C, 20 s) on the symptomless NHR of barley to TMV and the role of the ROS superoxide (O) in maintaining NHR. Heat stress and antioxidant (superoxide dismutase and catalase, SOD + CAT) treatments resulted in 50-100% higher TMV levels, while combined heat shock and SOD + CAT application caused further increases in TMV and appearance of cell and tissue death resembling a hypersensitive response (HR). An early (from 2 h after inoculation) burst of O was essentially absent in TMV-infected barley exposed to short-term heat stress pre-treatments. Expression of barley genes regulating ROS (O) metabolism (, ) and cell death () displayed an inverse correlation with TMV levels even at later time points (1-4 days after inoculation), implying a role in symptomless NHR, while increased levels of the antioxidant glutathione marked heat stress-induced suppression of NHR. We demonstrated that short-term heat stress and antioxidant treatments result in compromised NHR of barley to TMV, pointing to the role of optimal temperatures and ROS (O) in symptomless NHR to virus infections.
我们之前的研究已经证明了最佳温度和活性氧（ROS）在维持大麦对白粉病的无症状非寄主抗性（NHR）中的作用。然而，温度和ROS在包括大麦在内的植物对病毒感染的NHR中的具体功能尚不清楚。尽管大麦是烟草花叶病毒（TMV）的非寄主，但这种病毒在约30°C的温度下可在大麦叶片中复制。在此，我们阐明了短期热应激预处理（30°C，3小时；49°C热激20秒）对大麦对TMV的无症状NHR的影响以及ROS超氧化物（O）在维持NHR中的作用。热应激和抗氧化剂（超氧化物歧化酶和过氧化氢酶，SOD + CAT）处理导致TMV水平提高50 - 100%，而联合热激和SOD + CAT处理则导致TMV进一步增加，并出现类似于过敏反应（HR）的细胞和组织死亡现象。在经历短期热应激预处理的TMV感染大麦中，基本上不存在早期（接种后2小时起）的O爆发。即使在后期时间点（接种后1 - 4天），调节ROS（O）代谢（，）和细胞死亡（）的大麦基因表达与TMV水平呈负相关，这意味着其在无症状NHR中发挥作用，而抗氧化剂谷胱甘肽水平的升高标志着热应激诱导的NHR抑制。我们证明了短期热应激和抗氧化剂处理会导致大麦对TMV的NHR受损，这表明最佳温度和ROS（O）在对病毒感染的无症状NHR中发挥作用。
