PDF(Pubmed)
Abstract：
Rice prolamins are categorized into three groups by molecular size (10, 13, or 16 kDa), while the 13 kDa prolamins are assigned to four subgroups (Pro13a-I, Pro13a-II, Pro13b-I, and Pro13b-II) based on cysteine residue content. Since lowering prolamin content in rice is essential to minimize indigestion and allergy risks, we generated four knockout lines using CRISPR-Cas9, which selectively reduced the expression of a specific subgroup of the 13 kDa prolamins. These four mutant rice lines also showed the compensatory expression of glutelins and non-targeted prolamins and were accompanied by low grain weight, altered starch content, and atypically-shaped starch granules and protein bodies. Transcriptome analysis identified 746 differentially expressed genes associated with 13 kDa prolamins during development. Correlation analysis revealed negative associations between genes in Pro13a-I and those in Pro13a-II and Pro13b-I/II subgroups. Furthermore, alterations in the transcription levels of 9 ER stress and 17 transcription factor genes were also observed in mutant rice lines with suppressed expression of 13 kDa prolamin. Our results provide profound insight into the functional role of 13 kDa rice prolamins in the regulatory mechanisms underlying rice seed development, suggesting their promising potential application to improve nutritional and immunological value.
摘要：
水稻醇溶蛋白按分子大小分为三类（10、13或16kDa），而13kDa醇溶蛋白被分配到四个亚组(Pro13a-I，Pro13a-II,Pro13b-I,和Pro13b-II)基于半胱氨酸残基含量。由于降低大米中的醇溶蛋白含量对于最大程度地减少消化不良和过敏风险至关重要，我们使用CRISPR-Cas9产生了四个敲除系,其选择性地降低了13kDa醇溶蛋白的特定亚组的表达。这四个突变体水稻品系还表现出谷蛋白和非靶向醇溶蛋白的代偿性表达，并伴随着低粒重，改变淀粉含量，和非典型的淀粉颗粒和蛋白体。转录组分析鉴定了746个在发育过程中与13kDa醇溶蛋白相关的差异表达基因。相关分析显示Pro13a-I中的基因与Pro13a-II和Pro13b-I/II亚组中的基因之间存在负相关。此外，在13kDa谷醇溶蛋白表达受抑制的突变水稻品系中，还观察到9种ER胁迫和17种转录因子基因的转录水平发生了变化。我们的结果为13kDa水稻醇溶蛋白在水稻种子发育的调控机制中的功能作用提供了深刻的见解，表明它们在改善营养和免疫价值方面有前途的潜在应用。
