Abstract: Stem cells in plant shoot apical meristem maintain a high level of pluripotency, providing the source of all above-ground tissues and organs. Since plants cannot move to escape from various stresses, protection of plant stem cells from viruses and other pathogens is essential for plant growth and development. Although it has long been known that compared with other parts of the plant, the shoot apex containing the stem cell niche is against virus invasion and accumulation, the related mechanism is still elusive. A recent study from the group of Zhong Zhao at University of Science and Technology of China uncovered the mechanism of how plant stem cells in Arabidopsis are immune to virus infection through WUS-mediated innate immunity. WUS responses to the infection of cucumber mosaic virus, and represses virus accumulation in the central zone and peripheral zone. WUS directly represses the transcription of several S-adenosyl- L-methionine-dependent methyltransferase genes, resulting in disturbed rRNA processing and ribosome stability which affecting viral protein synthesis. This study reveals a conserved and broad-spectrum strategy of antiviral immunity in plant stem cells, which provides high values in both theory and application.

Key words: Arabidopsis, stem cell, WUS, MTase, rRNA, protein synthesis