Metabolic coordination of rice seed development to nighttime warming: In-situ determination of cellular redox states using picolitre pressure-probe electrospray-ionization mass spectrometry
Metabolic coordination of rice seed development to nighttime warming: In-situ determination of cellular redox states using picolitre pressure-probe electrospray-ionization mass spectrometry
复制标题
DOI：
10.1016/j.envexpbot.2021.104515
复制
发表时间：
2021-05-18
影响因子：
5.7
通讯作者：
Wada, Hiroshi
中科院分区：
文献类型：
--
作者：
Chang, Fang-Yu;Hatakeyama, Yuto;Wada, Hiroshi
水稻成熟期夜温过高严重影响水稻产量和品质。HNT促进胚的生长和发育中的籽粒中垩白的形成，伴随着胚乳细胞大小的减小。虽然这些反应在籽粒中可能是生理上相互作用的，但哪些信号参与了加速胚胎发育仍然没有确定。在这项工作中，我们已经使用皮升压力探针电喷雾电离质谱（picoPPESI-MS）进行单细胞代谢组学在几个地区在HNT处理的谷物，胚盾片和外胚乳在基础（'白垩区域'在成熟）和中间（'半透明区域'在成熟作为参考）的位置。显微镜观察表明，HNT促进了盾片细胞的增殖速率。当胚胎细胞扩增速率达到最大值时，检测到几种代谢的空间差异，包括抗坏血酸-谷胱甘肽（ASC-GSH）途径和嘌呤，以及胚胎盾片细胞中大量的糖和氨基酸积累。在HNT处理的胚胎中，活性细胞扩增期间GSH含量没有处理差异，尽管对比观察到由于氧化型谷胱甘肽（GSSG）含量减少而导致GSH/GSSG比值增加。在胚乳中，在HNT条件下也检测到更大的ASC积累，ASC/脱氢抗坏血酸比率存在差异。由于休眠往往与GSSG浓度相关，因此可以得出结论，在细胞水平上检测到的GSH氧化还原稳态的空间调节可能是必不可少的HNT处理种子的休眠缓解和胚生长加速。
High night temperature (HNT) at the ripening stage severely affects both rice yield and quality. HNT accelerates embryo growth and chalky formation in the developing grains, accompanying with a diminishment of endosperm cell size. Although these responses may be physiologically interacted each other in the grains, what signals are involved in the accelerated embryo development remains undetermined. In this work, we have used picolitre pressure-probe electrospray-ionization mass spectrometry (picoPPESI-MS) to conduct single-cell metabolomics at several regions in HNT-treated grains, embryonic scutellum and outer endosperms in the basal ('chalky region' at maturation) and middle ('translucent region' at maturation as a reference) positions. Microscopic observations showed that HNT promoted cell expansion rate in the scutellum. When embryonic cell expansion rate reached the maximum, spatial differences in several metabolisms including ascorbate-glutathione (ASC-GSH) pathway and purine were detected, together with considerable sugar and amino acid accumulations in embryonic scutellum cells. There was no treatment difference in GSH content during active cell expansion in HNT-treated embryos, although an increase in GSH/GSSG ratio due to a reduction in oxidized glutathione (GSSG) content has been contrastingly observed. In the endosperms, greater ASC accumulation with a difference in ASC/dehydroascobic acid ratio has been also detected under HNT conditions. Since dormancy is often correlated with GSSG concentration, it is concluded that spatial regulation of GSH redox homeostasis detected at cell-level might be essential for dormancy alleviation and embryo growth accelerated in HNT-treated seeds.