Unravelling the metabolic and phytohormonal changes in anthers exposed to heat stress would help identify mechanisms regulating heat stress tolerance during the sensitive reproductive stage. Two spring wheat genotypes contrasting for heat tolerance were exposed to heat stress during heading in controlled environment chambers. Anthers were collected from main and primary spikes for metabolic and phytohormonal profiling. A significant reduction in seed set (38%), grain number (54%) and grain weight (52%) per plant was recorded in the sensitive (KSG1177) but not in the tolerant (KSG1214) genotype under heat stress compared to control. Anther metabolite accumulation did not vary quantitatively between main and primary spikes. Hierarchical clustering of the genotypes and treatments using metabolites and phytohormones revealed a distinct cluster for KSG1177 under heat stress from that of control and KSG1214. A significant increase in N-based amino acids, ABA, IAA-conjugate and a decrease in polyamines and organic acids were observed in wheat anthers exposed to heat stress. Unlike KSG1214, a significantly higher accumulation of amino acids, ABA and IAA-conjugate in anthers of the sensitive KSG1177 was recorded under heat stress. These findings provide the rationale and direction towards developing molecular markers for enhancing heat stress tolerance in wheat. This article is protected by copyright. All rights reserved.

中文翻译：

---

花药中增强的 N 代谢物、ABA 和 IAA 结合物激发春小麦的热敏感性

揭示暴露于热应激的花药的代谢和植物激素变化将有助于确定在敏感生殖阶段调节热应激耐受性的机制。两种耐热性不同的春小麦基因型在抽穗期间在受控环境室中暴露于热应激。从主要和主要尖峰收集花药用于代谢和植物激素分析。与对照相比，在热胁迫下，敏感 (KSG1177) 基因型记录的每株种子集 (38%)、粒数 (54%) 和粒重 (52%) 显着减少，但在耐受 (KSG1214) 基因型中没有记录。主要和初级尖峰之间的花药代谢物积累在数量上没有变化。使用代谢物和植物激素对基因型和处理进行分层聚类，揭示了在热应激下 KSG1177 与对照和 KSG1214 的不同聚类。在暴露于热应激的小麦花药中观察到 N 基氨基酸、ABA、IAA 结合物的显着增加以及多胺和有机酸的减少。与 KSG1214 不同的是，在热应激下，敏感 KSG1177 的花药中氨基酸、ABA 和 IAA 结合物的积累显着增加。这些发现为开发用于增强小麦热胁迫耐受性的分子标记提供了基本原理和方向。本文受版权保护。版权所有。在暴露于热应激的小麦花药中观察到 IAA 结合物以及多胺和有机酸的减少。与 KSG1214 不同，在热应激下，敏感的 KSG1177 花药中氨基酸、ABA 和 IAA 结合物的积累显着增加。这些发现为开发用于增强小麦热胁迫耐受性的分子标记提供了基本原理和方向。本文受版权保护。版权所有。在暴露于热应激的小麦花药中观察到 IAA 结合物以及多胺和有机酸的减少。与 KSG1214 不同的是，在热应激下，敏感 KSG1177 的花药中氨基酸、ABA 和 IAA 结合物的积累显着增加。这些发现为开发用于增强小麦热胁迫耐受性的分子标记提供了基本原理和方向。本文受版权保护。版权所有。本文受版权保护。版权所有。本文受版权保护。版权所有。