Co-Innovation Center for Sustainable Forestry in Southern China, Key Laboratory of Forest Genetics and Biotechnology, Ministry of Education, Nanjing Forestry University, Nanjing 210037, China.
Int J Mol Sci. 2022 Sep 5;23(17):10185. doi: 10.3390/ijms231710185.
Mitogen-activated protein kinase (MAPK) cascades are highly conserved signal transduction modules, which transmit environmental signals in plant cells through stepwise phosphorylation and play indispensable roles in a wide range of physiological and biochemical processes. Here, we isolated and characterized a gene encoding MKK2 protein from poplar through the rapid amplification of cDNA ends (RACE). The full-length gene was 1571 bp, including a 1068 bp open reading frame (ORF) encoding 355 amino acids, and the putative PeMKK2a protein belongs to the PKc_like (protein kinase domain) family (70-336 amino acids) in the PKc_MAPKK_plant subfamily and contains 62 sites of possible phosphorylation and two conserved domains, DLK and S/T-xxxxx-S/T. Detailed information about its gene structure, sequence similarities, subcellular localization, and transcript profiles under salt-stress conditions was revealed. Transgenic poplar lines overexpressing exhibited higher activities of superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) than non-transgenic poplar under salt stress conditions. These results will provide insight into the roles of MAPK signaling cascades in poplar response to salt stress.
丝裂原活化蛋白激酶（MAPK）级联反应是高度保守的信号转导模块，通过逐步磷酸化将环境信号传递到植物细胞中，并在广泛的生理和生化过程中发挥不可或缺的作用。在这里，我们通过快速扩增 cDNA 末端（RACE）从杨树中分离和鉴定了一个编码 MKK2 蛋白的基因。全长基因长 1571bp，包括一个编码 355 个氨基酸的 1068bp 开放阅读框（ORF），推测的 PeMKK2a 蛋白属于蛋白激酶域家族（70-336 个氨基酸）在 PKc_MAPKK_plant 亚家族中，并包含 62 个可能的磷酸化位点和两个保守结构域，DLK 和 S/T-xxxxx-S/T。揭示了其基因结构、序列相似性、亚细胞定位和盐胁迫条件下转录谱的详细信息。在盐胁迫条件下，过表达的转基因杨树系的超氧化物歧化酶（SOD）、过氧化氢酶（CAT）和过氧化物酶（POD）活性均高于非转基因杨树。这些结果将为 MAPK 信号级联反应在杨树应对盐胁迫中的作用提供深入了解。
