Jiangsu Key Laboratory of Crop Genetics and Physiology, Jiangsu Key Laboratory of Crop Cultivation and Physiology, Agricultural College of Yangzhou University, Yangzhou, 225009, P. R. China.
Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, Yangzhou University, Yangzhou, 225009, P. R. China.
BMC Plant Biol. 2021 Sep 23;21(1):434. doi: 10.1186/s12870-021-03214-z.
Kernel development and starch formation are the primary determinants of maize yield and quality, which are considerably influenced by drought stress. To clarify the response of maize kernel to drought stress, we established well-watered (WW) and water-stressed (WS) conditions at 1-30 days after pollination (dap) on waxy maize (Zea mays L. sinensis Kulesh).
Kernel development, starch accumulation, and activities of starch biosynthetic enzymes were significantly reduced by drought stress. The morphology of starch granules changed, whereas the grain filling rate was accelerated. A comparative proteomics approach was applied to analyze the proteome change in kernels under two treatments at 10 dap and 25 dap. Under the WS conditions, 487 and 465 differentially accumulated proteins (DAPs) were identified at 10 dap and 25 dap, respectively. Drought induced the downregulation of proteins involved in the oxidation-reduction process and oxidoreductase, peroxidase, catalase, glutamine synthetase, abscisic acid stress ripening 1, and lipoxygenase, which might be an important reason for the effect of drought stress on kernel development. Notably, several proteins involved in waxy maize endosperm and starch biosynthesis were upregulated at early-kernel stage under WS conditions, which might have accelerated endosperm development and starch synthesis. Additionally, 17 and 11 common DAPs were sustained in the upregulated and downregulated DAP groups, respectively, at 10 dap and 25 dap. Among these 28 proteins, four maize homologs (i.e., A0A1D6H543, B4FTP0, B6SLJ0, and A0A1D6H5J5) were considered as candidate proteins that affected kernel development and drought stress response by comparing with the rice genome.
The proteomic changes caused by drought were highly correlated with kernel development and starch accumulation, which were closely related to the final yield and quality of waxy maize. Our results provided a foundation for the enhanced understanding of kernel development and starch formation in response to drought stress in waxy maize.
玉米的产量和品质主要取决于内核发育和淀粉形成，而这两个方面都受到干旱胁迫的显著影响。为了阐明玉米内核对干旱胁迫的响应，我们在糯玉米授粉后 1-30 天（DAP）建立了充分供水（WW）和水分胁迫（WS）条件。
干旱胁迫显著降低了内核发育、淀粉积累和淀粉生物合成酶的活性。淀粉颗粒的形态发生变化，而籽粒灌浆速率加快。我们应用比较蛋白质组学方法分析了两个处理下 10 DAP 和 25 DAP 内核的蛋白质组变化。在 WS 条件下，分别在 10 DAP 和 25 DAP 时鉴定到 487 和 465 个差异积累蛋白（DAP）。干旱诱导了与氧化还原过程和氧化还原酶、过氧化物酶、过氧化氢酶、谷氨酰胺合成酶、脱落酸应激成熟 1 和脂氧合酶相关的蛋白质下调，这可能是干旱胁迫对内核发育影响的一个重要原因。值得注意的是，在 WS 条件下，早期内核阶段有几个参与糯玉米胚乳和淀粉生物合成的蛋白质上调，这可能加速了胚乳发育和淀粉合成。此外，在 10 DAP 和 25 DAP 时，在上调和下调的 DAP 组中分别有 17 个和 11 个共同的 DAP 持续存在。在这 28 个蛋白质中，通过与水稻基因组比较，有 4 个玉米同源物（即 A0A1D6H543、B4FTP0、B6SLJ0 和 A0A1D6H5J5）被认为是影响内核发育和干旱胁迫响应的候选蛋白。
干旱引起的蛋白质组变化与内核发育和淀粉积累高度相关，这与糯玉米的最终产量和品质密切相关。我们的研究结果为深入了解糯玉米内核对干旱胁迫的响应提供了基础。
