Priming is a potential way to enhance stress tolerance in plants. Winter wheat adaptation to harsh environmental conditions is a prominent global predicament. To enhance the productivity and its tolerance to rapidly changing world's environment, wheat plants were subjected to different heat priming events at early growth stages, which effects were studied on subsequent heat stress at booting and flowering stages. The study aimed to observe the major changes in photosynthetic characteristics, antioxidant enzymes system, and sugar metabolism in leaves during wheat adaptation to heat stress applied at booting and flowering stages after heat priming at early growth stage. Heat stress mostly affected the plant's development with a significant reduction in yield, yield components, biomass, osmotic potential (OP), leaf relative water potential (LRWP), and plant photosystem. However, the concomitant increase of membrane injury index (MII), reactive oxygen species (ROS) production, enzymatic activities, and sugar metabolism in primed plants enabled winter wheat plants to tolerate heat stress more after low heat priming (LP) than moderate heat priming (MP). Furthermore, MP at early growth stages reduced the biomass, OP, LRWP, and photosynthetic system while the remarkable increase in sugar metabolism and enzymatic activities increased the ROS production, yield, and yield components under heat stress applied at booting stage. Similarly, LP successfully improved plant tolerance to heat stress applied at flowering stage. In conclusion, LP at early growth stage was beneficial to sustain to heat stress during flowering stage, while MP at early growth stage helped winter wheat to better adapt to heat stress at booting stage. These results encompass a novel research direction for the adaptation of winter wheat to harsh environmental conditions to reduce yield loss.

中文翻译：

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冬小麦生育早期热引发耐高温性综合评价

引发是增强植物抗逆性的潜在方法。冬小麦对恶劣环境条件的适应是一个突出的全球困境。为了提高生产力及其对快速变化的世界环境的耐受性，小麦在生长早期经历了不同的热引发事件，研究了这些事件对随后的孕穗期和开花期热应激的影响。本研究旨在观察小麦在生育早期热引发后对孕穗期和开花期热胁迫的适应过程中叶片光合特性、抗氧化酶系统和糖代谢的主要变化。热应激主要影响植物的发育，显着降低产量、产量成分、生物量、渗透势 (OP)、叶相对水势（LRWP）和植物光系统。然而，与中度热引发相比，低温引发 (LP) 后，冬小麦植物在低温引发 (LP) 后对热应激的耐受性更强，同时伴随的膜损伤指数 (MII)、活性氧 (ROS) 产生、酶活性和糖代谢增加（国会议员）。此外，生长早期的 MP 降低了生物量、OP、LRWP 和光合系统，而糖代谢和酶活性的显着增加增加了孕穗期热胁迫下 ROS 的产生、产量和产量成分。同样，LP 成功地提高了植物对开花期热应激的耐受性。综上所述，生长期LP有利于开花期承受热应激，而生育早期的MP有助于冬小麦在孕穗期更好地适应热胁迫。这些结果涵盖了冬小麦适应恶劣环境条件以减少产量损失的新研究方向。