Song Zhihua, Yang Qing, Dong Biying, Wang Shengjie, Xue Jingyi, Liu Ni, Zhou Xiaomiao, Li Na, Dandekar Abhaya M, Cheng Lailiang, Meng Dong, Fu Yujie
State Key Laboratory of Efficient Production of Forest Resources, Beijing Forestry University, Beijing 100083, China; The Key Laboratory for Silviculture and Conservation of Ministry of Education, Beijing Forestry University, Beijing 100083, China; Ecological Observation and Research Station of Heilongjiang Sanjiang Plain Wetlands, National Forestry and Grassland Administration, Beijing Forestry University, Beijing 100083, China.
Department of Plant Sciences, University of California at Davis, Davis, CA 95616, USA.
Dev Cell. 2025 May 19;60(10):1439-1453.e5. doi: 10.1016/j.devcel.2024.12.033. Epub 2025 Jan 13.
Sorbitol, a main photosynthate and transport carbohydrate in all tree fruit species in Rosaceae, acts as a signal controlling resistance against Alternaria (A.) alternata in apple by altering the expression of the MdNLR16 resistance gene via the MdWRKY79 transcription factor. However, it is not known if N-methyladenosine (mA) methylation of the mRNAs of these genes participates in the process. Here, we found that decreased sorbitol synthesis in apple leaves leads to a transcriptome-wide reduction in the mA modification, with fewer transcripts containing two or more methylation sites. We identified two methyltransferases, MdVIR1 and MdVIR2, that respond to sorbitol and A. alternata inoculation and positively control resistance to A. alternata. MdVIR1 and MdVIR2 act on MdWRKY79 and MdNLR16 mRNAs, and the resulting mA modification stabilizes their mRNAs and improves translation efficiency. These data identify that mA modification through MdVIR1 and MdVIR2 methyltransferases is essential for sorbitol-controlled resistance to A. alternata.
山梨醇是蔷薇科所有树果物种中的主要光合产物和运输碳水化合物，它通过MdWRKY79转录因子改变MdNLR16抗性基因的表达，从而作为一种信号控制苹果对链格孢菌的抗性。然而，尚不清楚这些基因的mRNA的N-甲基腺苷（mA）甲基化是否参与该过程。在此，我们发现苹果叶片中山梨醇合成的减少导致转录组范围内mA修饰的减少，含有两个或更多甲基化位点的转录本更少。我们鉴定出两种甲基转移酶MdVIR1和MdVIR2，它们对山梨醇和链格孢菌接种有反应，并正向控制对链格孢菌的抗性。MdVIR1和MdVIR2作用于MdWRKY79和MdNLR16的mRNA，产生的mA修饰使它们的mRNA稳定并提高翻译效率。这些数据表明，通过MdVIR1和MdVIR2甲基转移酶进行的mA修饰对于山梨醇控制的对链格孢菌的抗性至关重要。
