Autophagy during Maize Endosperm Development Dampens Oxidative Stress and Promotes Mitochondrial Clearance.
Autophagy during Maize Endosperm Development Dampens Oxidative Stress and Promotes Mitochondrial Clearance.
复制标题
玉米胚乳发育过程中的自噬抑制氧化应激并促进线粒体清除。
DOI：
10.1093/plphys/kiad340
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发表时间：
2023-06
期刊：
影响因子：
7.4
通讯作者：
Jessica A S Barros;Elizabeth C. Chatt;Robert C. Augustine;Fionn McLoughlin;Faqiang Li;M. Otegui;R. Vierstra
中科院分区：
文献类型：
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作者：
Jessica A S Barros;Elizabeth C. Chatt;Robert C. Augustine;Fionn McLoughlin;Faqiang Li;M. Otegui;R. Vierstra
通过自噬的大分子的选择性周转为再循环细胞成分和去除多余的和受损的细胞器、膜和蛋白质提供了关键的稳态机制。为了更好地了解自噬如何影响种子成熟和营养储存，我们通过综合多组学方法研究了玉米（Zea mays）胚乳在其早期和中期发育阶段，使用影响自噬体组装所需的核心自噬因子AUTOPHAGY（ATG）-12的突变体。令人惊讶的是，在这些发育窗口的突变胚乳积累正常量的淀粉和玉米醇溶蛋白储藏蛋白。然而，该组织获得了一个实质性改变的代谢组，特别是与氧化应激和硫代谢有关的化合物，包括胱氨酸，脱氢抗坏血酸，cys-谷胱甘肽二硫化物，葡萄糖二酸和半乳糖二酸的增加，以及过氧化物和抗氧化剂谷胱甘肽的减少。虽然在相关的转录组的变化是温和的，蛋白质组强烈改变atg 12胚乳，特别是线粒体蛋白水平的增加，而不伴随着mRNA丰度的增加。虽然细胞学上观察到较少的线粒体，但基于扩张嵴的积累，增加的数量出现功能障碍，与衰减的线粒体自噬一致。总的来说，我们的研究结果证实，在玉米胚乳发育过程中，大自噬在淀粉和贮藏蛋白的积累中起着次要作用，但可能有助于防止氧化应激，并在组织成熟过程中清除不需要的/功能失调的线粒体。
The selective turnover of macromolecules by autophagy provides a critical homeostatic mechanism for recycling cellular constituents and for removing superfluous and damaged organelles, membranes, and proteins. To better understand how autophagy impacts seed maturation and nutrient storage, we studied maize (Zea mays) endosperm in its early and middle developmental stages via an integrated multi-omics approach using mutants impacting the core macroautophagy factor AUTOPHAGY (ATG)-12 required for autophagosome assembly. Surprisingly, the mutant endosperm in these developmental windows accumulated normal amounts of starch and Zein storage proteins. However, the tissue acquired a substantially altered metabolome, especially for compounds related to oxidative stress and sulfur metabolism, including increases in cystine, dehydroascorbate, cys-glutathione disulfide, glucarate and galactarate, and decreases in peroxide and the anti-oxidant glutathione. While changes in the associated transcriptome were mild, the proteome was strongly altered in the atg12 endosperm, especially for increased levels of mitochondrial proteins without a concomitant increase in mRNA abundances. Although fewer mitochondria were seen cytologically, a heightened number appeared dysfunctional based on the accumulation of dilated cristae, consistent with attenuated mitophagy. Collectively, our results confirm that macroautophagy plays a minor role in the accumulation of starch and storage proteins during maize endosperm development, but likely helps protect against oxidative stress and clears unneeded/dysfunctional mitochondria during tissue maturation.