Department of Plant Production and Genetics, Shahid Chamran University of Ahvaz, Ahvaz, Iran.
Department of Medicinal Plants, Faculty of Agriculture and Natural Resources, Arak University, Arak, 38156-8-8349, Iran.
BMC Plant Biol. 2024 Nov 15;24(1):1080. doi: 10.1186/s12870-024-05781-3.
Future climates will realise increasingly frequent extreme weather events, which will impact on the quantum and quality of crop production. While effects of extreme heat on crop production have been well studied hitherto, there remains a dearth of knowledge pertaining to the impacts of extreme heat on grain quality. As such, our purpose here was to evaluate the effects of terminal heat stress on the physicochemical properties and composition of seed oil of safflower plants. Using two contemporary cultivars with varying genetic tolerance to heat stress (Faraman and Sofeh), we found that exposure to extreme heat reduced grain yield by 53-57%. Four fatty acids (palmitic, stearic, oleic and linoleic acid) comprised 96-99% of total fatty acid methyl esters; relative composition varied in response to heat stress and other environmental conditions. In the first experimental year (2017-18), saturated fatty acids in Sofeh and Faraman cultivars increased by 69% and 18% respectively, while unsaturated fatty acids decreased by 9% and 4%, respectively. In the second experimental year (2018-19), saturated fatty acids increased by 10% in Sofeh and by less than 1% in Farman, while unsaturated fatty acids in both cultivars were not significantly altered. Physicochemical parameters differed across years and cultivars; exposure to high temperature increased chlorophyll and carotenoid content in Sofeh, but decreased the said parameters in Faraman. In 2017-18, effects of heat stress on thiobarbituric acid were variable, but in 2018-19, thiobarbituric acid increased in both cultivars. In all cases, saponification and iodine content increased in response to heat stress. In sum, the fatty acid profile of safflower exposed to terminal heat stress was less affected compared with oil physicochemical parameters, due to greater temperature sensitivity of the latter.
未来的气候将出现越来越频繁的极端天气事件，这将影响作物的数量和质量。虽然极端高温对作物生产的影响已经得到了很好的研究，但对于极端高温对谷物质量的影响，人们的了解仍然很少。因此，我们的目的是评估终末热胁迫对红花植物种子油的理化性质和组成的影响。我们使用两个具有不同遗传耐热性的现代品种（Faraman 和 Sofeh），发现暴露在极端高温下会使粮食产量减少 53-57%。四种脂肪酸（棕榈酸、硬脂酸、油酸和亚油酸）占总脂肪酸甲酯的 96-99%；相对组成因热胁迫和其他环境条件而异。在第一个实验年（2017-18 年），Sofeh 和 Faraman 品种中的饱和脂肪酸分别增加了 69%和 18%，而不饱和脂肪酸分别减少了 9%和 4%。在第二个实验年（2018-19 年），Sofeh 中的饱和脂肪酸增加了 10%，而 Faraman 中的增加不到 1%，而两个品种中的不饱和脂肪酸没有明显变化。理化参数因年份和品种而异；在 Sofeh 中，高温暴露增加了叶绿素和类胡萝卜素的含量，但在 Faraman 中降低了上述参数。在 2017-18 年，热胁迫对硫代巴比妥酸的影响是可变的，但在 2018-19 年，两个品种中的硫代巴比妥酸都增加了。在所有情况下，皂化值和碘值都因热胁迫而增加。总的来说，与油的理化参数相比，暴露于终末热胁迫的红花的脂肪酸谱受影响较小，因为后者对温度更敏感。
