Plant growth and development are sustained by continuous cell division in the meristems, which is perturbed by various environmental stresses. For the maintenance of meristematic functions, it is essential that cell division be coordinated with cell differentiation. However, it is unknown how the proliferative activities of the meristems and the coordination between cell division and differentiation are maintained under stressful conditions. Here we show that a rice protein, RSS1, whose stability is controlled by cell cycle phases, contributes to the vigour of meristematic cells and viability under salinity conditions. These effects of RSS1 are exerted by regulating the G1–S transition, possibly through an interaction of RSS1 with protein phosphatase 1, and are mediated by the phytohormone, cytokinin. RSS1 is conserved widely in plant lineages, except eudicots, suggesting that RSS1-dependent mechanisms might have been adopted in specific lineages during the evolutionary radiation of angiosperms.
植物的生長(zhǎng)和發(fā)育需要分生組織持續(xù)進(jìn)行細(xì)胞分裂來(lái)維持，這一過(guò)程經(jīng)常受到各種環(huán)境逆境的影響。細(xì)胞分裂和細(xì)胞分化對(duì)分生功能的維持是非常重要的。然而目前對(duì)逆境條件下，分生組織是如何維持增殖活性、協(xié)調(diào)細(xì)胞分裂和分化的，還所知甚少。本研究發(fā)現(xiàn)一個(gè)水稻蛋白R(shí)SS1對(duì)鹽脅迫條件下分生細(xì)胞活性和活力的維持發(fā)揮作用，RSS1的穩(wěn)定性受到細(xì)胞周期階段的調(diào)控。RSS1可能是通過(guò)由細(xì)胞分裂素介導(dǎo)的、RSS1與蛋白磷酸化酶1（PP1）的互作，調(diào)節(jié)G1-S期的轉(zhuǎn)換。除雙子葉植物外，RSS1在植物中是非常保守的，表明依賴(lài)RSS1的調(diào)節(jié)機(jī)制在被子植物輻射演化過(guò)程中，為某些特定的支系所采用。