Toda-Matsunaga Sachiko, Toda Yusuke, Mega Ryosuke, Tadano Shota, Alyza Megumi, Yamasaki Yuji, Akashi Kinya, Tsujimoto Hisashi
United Graduate School of Agricultural Sciences, Tottori University, Tottori, Japan.
Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan.
Front Plant Sci. 2025 Mar 28;16:1539926. doi: 10.3389/fpls.2025.1539926. eCollection 2025.
A capacity for reliable germination under elevated temperatures is a crucial factor in maintaining the stability of bread wheat () yields in the context of climate change. Although the environment of the parent plant during growth is a known factor affecting seed germinability, the effect of this environment on the heat tolerance of wheat seeds has not been investigated in detail. To investigate the effect of exposure to high temperatures during growth, plants were exposed to 38°C at various growth stages. In germination test, seeds exposed to heat during their development had better heat germinability than the control. On the other hand, high temperatures before the seed development stage resulted in a lower temperature germinability compared to the control. To identify critical factors that altered heat germinability, we analyzed heat shock protein expression, fatty acid composition, and metabolite profiles. High-temperature treatment during seed formation increased the expression of heat shock proteins and reduced the degree of unsaturation of fatty acids in the seeds, which may enhance the ability of seeds to survive and germinate at high temperatures. There was a significant treatment effect on the overall metabolite content of the seeds. PLS regression analysis using the germination test results revealed that taurine, thymidine, beta-alanine, sinapic acid, and deoxyguanosine contributed significantly to germination rate. These findings suggest that the combined influence of these metabolites may play a role in acquiring seed germinability under high-temperature conditions during the growth period of the parent plants. These findings suggest potential components of a molecular mechanism in bread wheat that is triggered by high temperature during seed development and results in the acquisition of heat germinability.
在气温升高的情况下具备可靠的发芽能力是在气候变化背景下维持面包小麦（）产量稳定性的关键因素。虽然母株生长期间的环境是影响种子发芽能力的一个已知因素，但这种环境对小麦种子耐热性的影响尚未得到详细研究。为了研究生长期间暴露于高温的影响，在不同生长阶段将植株置于38°C环境中。在发芽试验中，发育期间经受高温的种子比对照具有更好的热发芽能力。另一方面，种子发育阶段之前的高温导致与对照相比温度发芽能力较低。为了确定改变热发芽能力的关键因素，我们分析了热休克蛋白表达、脂肪酸组成和代谢物谱。种子形成期间的高温处理增加了热休克蛋白的表达并降低了种子中脂肪酸的不饱和度，这可能增强种子在高温下存活和发芽的能力。对种子的总体代谢物含量有显著的处理效应。使用发芽试验结果进行的偏最小二乘回归分析表明，牛磺酸、胸苷、β-丙氨酸、芥子酸和脱氧鸟苷对发芽率有显著贡献。这些发现表明，这些代谢物的综合影响可能在母株生长期间的高温条件下获得种子发芽能力方面发挥作用。这些发现提示了面包小麦中一种分子机制的潜在组成部分，该机制由种子发育期间的高温触发并导致获得热发芽能力。
