近日，Frontiers in Plant Science 在线发表中国农大王建华和中国农科院刘允军团队题为“ Transcriptome Analysis of Maize Immature Embryos Reveals the Roles of Cysteine in Improving Agrobacterium Infection Efficiency”研究论文，系统解析了半胱氨酸提高农杆菌介导的玉米幼胚转化效率的机理。
最近几年，玉米的遗传转化效率不断提高，其中抗氧化剂半胱氨酸可明显提高玉米幼胚的农杆菌转化效率，但其机理尚不明确，在本研究中作者证明通过在共培养培养基中添加半胱氨酸可以明显HiII和Z31两个品种的农杆菌转化效率，半胱氨酸处理后的幼胚活性氧的含量要高于对照组，通过转录组测序进一步研究证明，半胱氨酸处理后939个基因表达上调，这些基因主要参与氧化还原反应过程，另外有549个基因表达下调，主要参与细胞壁和细胞膜代谢过程。
Maize Agrobacterium-mediated transformation efficiency has been greatly improved in recent years. Antioxidants, such as, cysteine, can significantly improve maize transformation frequency through improving the Agrobacterium infection efficiency. However, the mechanism underlying the transformation improvement after cysteine exposure has not been elucidated. In this study, we showed that the addition of cysteine to the co-cultivation medium significantly increased the Agrobacterium infection efficiency of hybrid HiII and inbred line Z31 maize embryos. Reactive oxygen species contents were higher in embryos treated with cysteine than that without cysteine. We further investigated the mechanism behind cysteine-related infection efficiency increase using transcriptome analysis. The results showed that the cysteine treatment up-regulated 939 genes and down-regulated 549 genes in both Z31 and HiII. Additionally, more differentially expressed genes were found in HiII embryos than those in Z31 embryos,suggesting that HiII was more sensitive to the cysteine treatment than Z31. GO analysis showed that the up-regulated genes were mainly involved in the oxidation reduction process. The up-regulation of these genes could help maize embryos to cope with the oxidative stress stimulated by Agrobacterium infection. The down-regulated genes were mainly involved in the cell wall and membrane metabolism, such as, aquaporin and expansin genes. Decreased expression of these cell wall integrity genes could loosen the cell wall, thereby improving the entry of Agrobacterium into plant cells. This study offers insight into the role of cysteine in improving Agrobacterium-mediated transformation of maize immature embryos.
特别声明：本文来源于'植物科学最前沿'，仅仅是出于传播信息的需要，作者如果不希望被转载或者联系转载稿费等事宜，请与我们接洽。