Cellular and molecular basis of low temperature tolerance in cereals

谷物耐低温的细胞和分子基础

• 批准号: 7199-2013
• 负责人: Sarhan, Fathey
• 金额: $ 3.42万
• 依托单位: Université du Québec à Montréal
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2017
• 资助国家: 加拿大
• 起止时间: 2017-01-01 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=630370
• 关键词: Cellular; molecular; basis; low; temperature

Winter cereals require prolonged exposure to low temperature (LT) to trigger the genetic mechanisms to induce freezing tolerance (FT) and to promote flowering through vernalization. Using different molecular and genomic approaches, several LT- responsive genes were identified from freezing tolerant wheat and rye in our laboratory. Expression analyses revealed that several of these genes are differentially expressed in winter and spring genotypes. Their expression was associated with the vernalization response and the capacity of wheat cultivars and other cereal species to cold acclimate and develop FT. Molecular and genetic studies designed to explain this differential expression have demonstrated that the level and duration of gene expression determine the degree of FT and depend on the vernalization response. As a consequence, the less tolerant spring cultivars, which do not require vernalization, cannot maintain the LT responsive genes in an up-regulated state. This limits their ability to achieve the same levels of FT as the vernalization responsive hardy winter cultivars. These genes and their products may have an important function in conferring FT and controlling flowering time. The goal of this research program is to understand the complex genetic mechanisms that control LT tolerance and vernalization. To achieve this goal, we will focus on the following objectives: 1) Identify and characterize the regulatory mechanisms and the signalling pathway that sense the cold and control the expression of the LT responsive genes. We will focus on the epigenetic regulation of cold response at both histone modifications and DNA methylation. In addition, the role of microRNAs and methyl-jasmonate in regulating these mechanisms will be studied; 2) determine the molecular and genetic connections between vernalization and cold acclimation. Understanding the molecular genetics of FT and flowering in temperate cereals will facilitate the development of the technology to manipulate these multigenic traits and produce crop species with sustainable production under changing climate conditions. This will have a tremendous impact on Canadian and world agriculture.

冬季谷类作物需要长时间的低温暴露来触发遗传机制诱导抗冻性并通过春化促进开花。本实验室利用不同的分子和基因组学方法，从抗冻小麦和黑麦中鉴定了几个LT应答基因。表达分析表明，这些基因中的几个差异表达的冬季和春季基因型。它们的表达与春化反应和小麦品种和其他谷类物种的冷驯化和发展FT的能力有关。旨在解释这种差异表达的分子和遗传研究表明，基因表达的水平和持续时间决定FT的程度，并取决于春化反应。因此，不需要春化处理的较不耐春性品种不能维持LT应答基因处于上调状态。这限制了它们达到与春化反应性哈代冬季品种相同水平的FT的能力。这些基因及其产物可能在赋予FT和控制开花时间方面具有重要功能。这项研究计划的目标是了解控制LT耐受性和春化的复杂遗传机制。为了实现这一目标，我们将集中在以下目标：1）确定和表征的调节机制和信号通路，感觉冷和控制LT响应基因的表达。我们将集中在组蛋白修饰和DNA甲基化的冷反应的表观遗传调控。此外，microRNA和茉莉酸甲酯在调控这些机制中的作用将被研究; 2）确定春化和冷驯化之间的分子和遗传联系。了解FT和温带谷物开花的分子遗传学将促进技术的发展，以操纵这些多基因性状，并在不断变化的气候条件下生产可持续生产的作物品种。这将对加拿大和世界农业产生巨大影响。