Hu Xiaojie, Chen Sheng, Ping Xiaoke, Siddique Kadambot H M, Cowling Wallace A
The UWA Institute of Agriculture, The University of Western Australia, Perth, WA 6000, Australia.
The UWA Institute of Agriculture, The University of Western Australia, Perth, WA 6000, Australia.
J Proteomics. 2025 Jun 13;319:105481. doi: 10.1016/j.jprot.2025.105481.
Heat stress significantly reduces canola seed production during the post-pollination stages. This study explored changes in the proteome of flowers on the main stem of three Brassica napus cultivars exposed to transient heat stress after pollination. Flowers at the 2nd to 5th reproductive nodes on the main stem were collected on days 0, 1, 3 and 6 of heat stress and control treatments. The three cultivars, Alku, AV-Ruby, and YM11, exhibited varying degrees of heat sensitivity and resilience based on seed production in pods at these reproductive nodes. The seed yield per pod under heat stress was 75.3 % of the control in Alku and 64.2 % in YM11. However, AV-Ruby retained 93.5 % of its seed yield under heat stress, from which we conclude AV-Ruby was more resilient to heat stress during the post-pollination stage than Alku or YM11. There were 474 differentially abundant proteins (DAPs) identified across all cultivars and time points. Among the DAPs, two HSP20-like chaperones (A0A078I8F7, A0A078JBL3) and one HSP-related protein (A0A078JJT8) were consistently highly abundant under heat and were strong candidates as heat responsive proteins. Pathways related to maintaining membrane integrity were specifically enriched in AV-Ruby, and deserve further study for their potential involvement in heat tolerance. SIGNIFICANCE OF THE STUDY: Heat stress is a major factor threatening seed yield in cool season crops including oilseed rape, particularly during the post-pollination stages when pollination, fertilization, and embryo development are highly vulnerable to elevated temperatures. A comparative proteomic analysis was carried out to identify heat-responsive proteins during the post-pollination period. Among the DAPs, three were consistently associated with heat stress response. A range of biological processes, including protein folding and stress signalling, were involved in a general response to heat stress in all cultivars. Furthermore, pathways related to maintaining membrane integrity were specifically enhanced in a heat-resilient cultivar. These findings provide new insights into the heat response at the protein level and lay the groundwork for identifying potential molecular targets for breeding heat-tolerant oilseed rape cultivars.
热应激显著降低了授粉后阶段油菜籽的产量。本研究探讨了三个甘蓝型油菜品种主茎上的花朵在授粉后遭受短暂热应激时蛋白质组的变化。在热应激和对照处理的第0、1、3和6天，采集主茎上第2至5个生殖节位的花朵。根据这些生殖节位豆荚中的种子产量，Alku、AV-Ruby和YM11这三个品种表现出不同程度的热敏感性和恢复力。热应激下，Alku每个豆荚的种子产量是对照的75.3%，YM11是64.2%。然而，AV-Ruby在热应激下保留了93.5%的种子产量，由此我们得出结论，AV-Ruby在授粉后阶段比Alku或YM11对热应激更具恢复力。在所有品种和时间点共鉴定出474种差异丰富蛋白（DAP）。在这些DAP中，两种类HSP20伴侣蛋白（A0A078I8F7、A0A078JBL3）和一种HSP相关蛋白（A0A078JJT8）在热应激下始终高度丰富，是热响应蛋白的有力候选者。与维持膜完整性相关的途径在AV-Ruby中特异性富集，因其可能参与耐热性而值得进一步研究。研究意义：热应激是威胁包括油菜在内的冷季作物种子产量的主要因素，尤其是在授粉、受精和胚胎发育极易受到温度升高影响的授粉后阶段。进行了一项比较蛋白质组学分析，以鉴定授粉后时期的热响应蛋白。在DAP中，有三种始终与热应激反应相关。包括蛋白质折叠和应激信号传导在内的一系列生物学过程参与了所有品种对热应激的一般反应。此外，与维持膜完整性相关的途径在耐热品种中特异性增强。这些发现为蛋白质水平的热响应提供了新的见解，并为鉴定耐热油菜品种的潜在分子靶点奠定了基础。
