Exploring chemical 'de-priming' and quantitative genetics to improve growth and yield of soybean under abiotic stress.

探索化学“去启动”和定量遗传学，以改善非生物胁迫下大豆的生长和产量。

基本信息

批准号：
BB/R019894/1
负责人：
Anna Amtmann
金额：
$ 65.67万
依托单位：
University of Glasgow
依托单位国家：
英国
项目类别：
Research Grant
财政年份：
2018
资助国家：
英国
起止时间：
2018 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=BB%2FR019894%2F1
关键词：
Exploring chemical de priming quantitative

项目摘要

One of the first changes in plants exposed to environmental stress is an increase of reactive oxygen species (ROS). During evolution, plants have 'learned' to interpret increased ROS as an early warning signal, and to use it as a trigger to induce physiological and biochemical responses that improve their chances of survival. Plant scientists are trying to understand the molecular components of stress signaling pathways and to exploit this information to develop strategies that can improve the stress tolerance of crops in the field. This is particularly important in India where the agricultural production of nutritious crops such as soybean is limited by environmental and climatic challenges arising from soil salinity, drought, water-logging and/or high temperature.'Chemical priming' has been proposed as a strategy to enhance the natural stress responses of a plant, for example through pre-treatment with low doses of ROS or ROS-producing agents. Indeed, faster or stronger induction of stress responses and improved plant stress tolerance has been reported for ROS-primed plants. However, our previous research in India has shown that the opposite approach - preventing early stress signaling by applying low concentrations of ROS-scavenging agents such as thiourea (TU) - also improves stress tolerance. The solution to this conundrum is likely to reside in the exact environmental condition ('stress scenario') under which tolerance is tested. To ensure survival, plants tend to prepare for the worst-case scenario. One would therefore expect that enhancing the natural plant responses through priming increases survival under severe long-term stress. However, in an agricultural setting some of the natural responses may be unnecessary and unwanted by the farmer. For example, production of stress-protective metabolites is energetically costly and can delay growth and development of the crop. Furthermore, some responses induced by one stress factor may exacerbate problems generated by another stress factor, e.g. closing stomata saves water under salt/drought stress but disables leaf cooling which is essential for combatting heat stress. Thus, if severe long-term stress does not occur, or is prevented through ad-hoc agricultural measures, crop varieties that ignore early stress signals ('happy-go-lucky' plants) could be better suited to farming in India than stress-sensitive ('panicky') varieties that induce strong stress responses. The aim of scenario-driven strategies would be to narrow the margin between actual and possible yield in a given stress situation.Following this line of argumentation we propose here a research programme that explores the benefits of both chemical and genetic de-priming for soybean production in Indian agriculture. Based on detailed physiological assays in the laboratory and yield data from field experiments we will establish a dose-effect curve of TU-treatments and determine the specific stress scenarios in which this approach improves soybean performance. The optimised TU formulation can immediately be applied in the field. In the longer term, TU application should be replaced by new custom varieties that are hard-wired to ignore early stress signals. To facilitate the development of 'happy-go-lucky' varieties we will therefore also investigate through RNA-sequencing the molecular processes that are targeted by TU, and carry out a genome-wide association study (GWAS) under single and combined salt/TU treatment. GWAS is possible with soybean because a large panel of accessions with re-sequenced genomes is already available. Correlating phenotypic data (root system architecture, biomass, yield) across these accessions with the genomic data will allow us to identify the genetic loci that underpin TU-modulation of stress responses. The information will enable the development of scenario-based custom varieties with improved stress tolerance through marker-assisted breeding or gene editing technology.

植物在受到环境胁迫时首先发生的变化之一是活性氧（ROS）的增加。在进化过程中，植物“学会”将活性氧的增加解释为早期预警信号，并将其用作诱发生理和生化反应的触发器，从而提高其生存机会。植物科学家正在尝试了解胁迫信号通路的分子组成，并利用这些信息来制定可以提高田间作物的胁迫耐受性的策略。这在印度尤为重要，因为大豆等营养作物的农业生产受到土壤盐分、干旱、涝渍和/或高温引起的环境和气候挑战的限制。“化学引发”已被提议作为一项战略增强植物的自然应激反应，例如通过用低剂量的 ROS 或 ROS 产生剂进行预处理。事实上，据报道，ROS 引发的植物可以更快或更强地诱导应激反应并提高植物的应激耐受性。然而，我们之前在印度的研究表明，相反的方法 - 通过应用低浓度的 ROS 清除剂（如硫脲 (TU)）来预防早期应激信号 - 也可以提高应激耐受性。这个难题的解决方案可能在于测试耐受性的确切环境条件（“压力场景”）。为了确保生存，植物往往会为最坏的情况做好准备。因此，人们期望通过引发来增强植物的自然反应，从而提高在严重的长期胁迫下的存活率。然而，在农业环境中，一些自然反应可能是农民不必要和不想要的。例如，生产应激保护性代谢物的能源成本很高，并且会延迟作物的生长和发育。此外，由一种压力因素引起的某些反应可能会加剧由另一种压力因素产生的问题，例如关闭气孔可以在盐/干旱胁迫下节省水分，但会阻碍叶片冷却，而这对于对抗热胁迫至关重要。因此，如果没有发生严重的长期胁迫，或者通过临时农业措施来预防，那么忽视早期胁迫信号的作物品种（“无忧无虑”的植物）可能比胁迫更适合印度的农业。敏感（“恐慌”）品种会引起强烈的应激反应。情景驱动策略的目标是缩小给定胁迫情况下实际产量和可能产量之间的差距。按照这一论点，我们在此提出一项研究计划，探索化学和遗传去启动对大豆生产的好处在印度农业中。根据实验室详细的生理测定和田间实验的产量数据，我们将建立 TU 处理的剂量效应曲线，并确定该方法改善大豆性能的具体胁迫情景。优化的 TU 配方可以立即应用于现场。从长远来看，TU 应用应该被新的定制品种所取代，这些品种本身就可以忽略早期的应激信号。因此，为了促进“无忧无虑”品种的开发，我们还将通过 RNA 测序来研究 TU 所针对的分子过程，并在单一和组合盐/TU 下进行全基因组关联研究 (GWAS)治疗。大豆的全基因组关联分析（GWAS）是可能的，因为已经有大量具有重新测序基因组的材料可供使用。将这些种质的表型数据（根系结构、生物量、产量）与基因组数据相关联，将使我们能够识别支持应激反应的 TU 调节的遗传位点。这些信息将有助于通过标记辅助育种或基因编辑技术开发具有更高抗逆性的基于场景的定制品种。