Key message

Rice is an important crop in the world. However, little is known about rice mRNA deadenylation, which is an important regulation step of gene expression at the post-transcriptional level. The CCR4–NOT1 complex contains two key components, CCR4 and CAF1, which are the main cytoplasmic deadenylases in eukaryotic cells. Expression of OsCAF1B was tightly coupled with low-temperature exposure. In the present study, we investigated the function of OsCAF1B in rice by characterizing the molecular and physiological responses to cold stress in OsCAF1B overexpression lines and dominant-negative mutant lines. Our results demonstrate that OsCAF1B plays an important role in growth and development of rice seedlings at low temperatures.

Abstract

Rice is a tropical and subtropical crop that is sensitive to low temperature, and activates a complex gene regulatory network in response to cold stress. Poly(A) tail shortening, also termed deadenylation, is the rate-limiting step of mRNA degradation in eukaryotic cells. CCR4-associated factor 1 (CAF1) proteins are important enzymes for catalysis of mRNA deadenylation in eukaryotes. In the present study, the role of a rice cold-induced CAF1, OsCAF1B, in adaptation of rice plants to low-temperature stress was investigated. Expression of OsCAF1B was closely linked with low-temperature exposure. The increased survival percentage and reduced electrolyte leakage exhibited by OsCAF1B overexpression transgenic lines subjected to cold stress indicate that OsCAF1B plays a positive role in rice growth under low ambient temperature. The enhancement of cold tolerance by OsCAF1B in transgenic rice seedlings involved OsCAF1B deadenylase gene expression, and was associated with elevated expression of late-response cold-related transcription factor genes. In addition, the expression level of OsCAF1B was higher in a cold-tolerant japonica rice cultivar than in a cold-sensitive indica rice cultivar. The results reveal a hitherto undiscovered function of OsCAF1B deadenylase gene expression, which is required for adaptation to cold stress in rice.

中文翻译：

---

CCR4相关因子1，OsCAF1B，赋予水稻幼苗低温胁迫耐受性

关键信息

水稻是世界上重要的农作物。然而，人们对水稻 mRNA 去腺苷酸化知之甚少，这是转录后水平基因表达的重要调控步骤。CCR4-NOT1 复合物包含两个关键成分，CCR4 和 CAF1，它们是真核细胞中主要的细胞质去腺苷酶。OsCAF1B的表达与低温暴露密切相关。在本研究中，我们通过表征OsCAF1B过表达系和显性失活突变系对冷胁迫的分子和生理反应来研究 OsCAF1B 在水稻中的功能。我们的研究结果表明，OsCAF1B 在水稻幼苗低温生长发育中起重要作用。

抽象的

水稻是热带和亚热带作物，对低温敏感，响应寒冷胁迫激活复杂的基因调控网络。Poly(A) 尾部缩短，也称为去腺苷酸化，是真核细胞中 mRNA 降解的限速步骤。CCR4 相关因子 1 (CAF1) 蛋白是催化真核生物中 mRNA 脱腺苷酸化的重要酶。在本研究中，研究了水稻低温诱导的 CAF1 OsCAF1B 在水稻植物适应低温胁迫中的作用。OsCAF1B的表达与低温暴露密切相关。OsCAF1B过表达转基因株系在低温胁迫下的存活率增加和电解质渗漏减少表明OsCAF1B在低温环境下对水稻生长具有积极作用。OsCAF1B 增强转基因水稻幼苗的耐寒性与 OsCAF1B 去腺苷酶基因的表达有关，并且与晚期反应冷相关转录因子基因的表达升高有关。此外，OsCAF1B在抗寒粳稻品种中的表达水平高于在冷敏感籼稻品种中的表达水平。水稻品种。结果揭示了 OsCAF1B 脱腺苷酶基因表达的一个迄今为止未被发现的功能，这是水稻适应寒冷胁迫所必需的。