Wu Jing, Liang Xiaoyu, Lin Miao, Lan Yangang, Xiang Yan, Yan Hanwei
Laboratory of Modern Biotechnology, School of Forestry and Landscape Architecture, Anhui Agricultural University, Hefei, China.
National Engineering Laboratory of Crop Stress Resistance Breeding, Anhui Agricultural University, Hefei, China.
Physiol Plant. 2023 Jan;175(1):e13869. doi: 10.1111/ppl.13869.
Mitogen-activated protein kinases (MAPKs) play important roles in plant growth and development, as well as hormone and stress responses by signaling to eukaryotic cells, through MAPK cascade, the presence of various cues; thereby, regulating various responses. The MAPK cascade consists mainly of three gene families, MAPK, MAPKK, and MAPKKK, which activate downstream signaling pathways through sequential phosphorylation. Although the MAPK cascade gene family has been reported in several species, there is a lack of comprehensive analysis in poplar. We identified 21 MAPK genes, 11 MAPKK genes, and 104 MAPKKK genes in Populus trichocarpa. The phylogenetic classification was supported by conservative motif, gene structure and motif analysis. Whole genome duplication has an important role in the expansion of MAPK cascade genes. Analysis of promoter cis-elements and expression profiles indicates that MAPK cascade genes have important roles in plant growth and development, abiotic and biotic stresses, and phytohormone response. Expression profiling revealed a significant upregulation of PtMAPK3-1 expression in response to drought, salt and disease stresses. Poplar transiently overexpressing PtMAPK3-1 and treated with methyl jasmonic acid (MeJA) had higher catalase and peroxidase levels than non-overexpressing poplar. This work represents the first complete inventory of the MAPK cascade in P. trichocarpa, which reveals that PtMAPK3-1 is induced by the MeJA hormone and participates in the MeJA-induced enhancement of the antioxidant enzyme system.
丝裂原活化蛋白激酶（MAPKs）在植物生长发育以及激素和应激反应中发挥着重要作用，它通过MAPK级联向真核细胞传递各种信号线索的存在，从而调节各种反应。MAPK级联主要由三个基因家族组成，即MAPK、MAPKK和MAPKKK，它们通过顺序磷酸化激活下游信号通路。尽管在多个物种中都报道过MAPK级联基因家族，但杨树中缺乏全面的分析。我们在毛果杨中鉴定出了21个MAPK基因、11个MAPKK基因和104个MAPKKK基因。保守基序、基因结构和基序分析支持了系统发育分类。全基因组复制在MAPK级联基因的扩增中起重要作用。对启动子顺式元件和表达谱的分析表明，MAPK级联基因在植物生长发育、非生物和生物胁迫以及植物激素反应中起重要作用。表达谱分析显示，PtMAPK3-1的表达在干旱、盐和病害胁迫下显著上调。瞬时过表达PtMAPK3-1并用茉莉酸甲酯（MeJA）处理的杨树比未过表达的杨树具有更高的过氧化氢酶和过氧化物酶水平。这项工作代表了毛果杨中MAPK级联的首个完整清单，揭示了PtMAPK3-1受MeJA激素诱导并参与MeJA诱导的抗氧化酶系统增强。
