For efficient gene delivery in plant systems, nonviral vector and DNA complexes require extracellular stability, cell wall/membrane translocation capability, and the ability to mediate both endosomal escape and intracellular DNA release. Peptides make appealing gene delivery vectors due to their DNA-binding, cell-penetrating, and endosome escape properties. However, DNA release within cells has so far been inefficient, which results in poor and delayed gene expression, while the lack of understanding of both internalization and trafficking mechanisms is a further obstacle to the design of efficient peptide gene delivery vectors. Here, we report successful gene delivery into plants using a cellular environment-responsive vector, BPCH7, which is an efficient cell-penetrating peptide with a cyclic DNA-binding domain that is formed by a disulfide bond between two cysteines. The cyclic structure of BPCH7 confers high avidity attachment to DNA in vitro. Following endocytosis into cells, disulfide bond cleavage facilitated by intracellular glutathione induces structural changes within BPCH7 that enable the release of the associated DNA cargo. Comparative studies with BPKH, a cell-penetrating peptide with a linear DNA-binding domain, show that BPCH7 maximized and expedited gene transfer in cells and unveil for the first time the crucial role of plant stomata in the internalization of peptide–DNA complexes.

中文翻译：

---

刺激应答肽，可在植物中有效传递和释放DNA

为了在植物系统中高效地传递基因，非病毒载体和DNA复合物需要细胞外稳定性，细胞壁/膜易位能力以及介导内体逃逸和细胞内DNA释放的能力。肽由于具有DNA结合，细胞穿透和内体逃逸特性而成为诱人的基因传递载体。然而，迄今为止，细胞内的DNA释放效率低下，导致基因表达差且延迟，而对内在化和运输机制的缺乏了解是设计有效肽基因递送载体的又一障碍。在这里，我们报告了使用细胞环境响应性载体BPCH7将基因成功传递到植物中的过程，它是一种有效的细胞穿透肽，具有由两个半胱氨酸之间的二硫键形成的环状DNA结合结构域。BPCH7的环状结构可在体外赋予DNA高亲和力。内吞进入细胞后，细胞内谷胱甘肽促进的二硫键裂解诱导BPCH7内的结构变化，从而使相关的DNA货物得以释放。BPKH是一种具有线性DNA结合结构域的细胞穿透肽，它的比较研究表明BPCH7最大化并加速了细胞中的基因转移，并首次揭示了植物气孔在肽DNA内在复合物中的关键作用。细胞内谷胱甘肽促进的二硫键断裂诱导了BPCH7内的结构变化，从而使相关的DNA货物得以释放。BPKH是一种具有线性DNA结合结构域的细胞穿透肽，它的比较研究表明BPCH7最大化并加速了细胞中的基因转移，并首次揭示了植物气孔在肽DNA内在复合物中的关键作用。细胞内谷胱甘肽促进的二硫键断裂诱导了BPCH7内的结构变化，从而使相关的DNA货物得以释放。BPKH是一种具有线性DNA结合结构域的细胞穿透肽，它的比较研究表明BPCH7最大化并加速了细胞中的基因转移，并首次揭示了植物气孔在肽DNA内在复合物中的关键作用。