Molecular mechanisms underlying plant adaptations to extreme environments

植物适应极端环境的分子机制

• 批准号: RGPIN-2020-06886
• 负责人: Weretilnyk, Elizabeth
• 金额: $ 2.4万
• 依托单位: McMaster University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2021
• 资助国家: 加拿大
• 起止时间: 2021-01-01 至 2022-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=741477
• 关键词: Molecular; mechanisms; underlying; plant; adaptations

The world's population is expected to exceed 9 billion by 2050. With a finite global land base for agriculture, we face huge uncertainties in how we can feed 2.5 billion more people. We must produce more food with less land but a concurrent challenge is the increasing frequency of unpredictable, severe episodes of adverse weather, conditions already leading to yield loss and catastrophic crop failures. We must find more effective ways of stabilizing yields and ensuring a secure and safe food supply, ideally involving fewer costly inputs like irrigation, fertilizers and crop protection chemicals. However, research identifying traits to improve crop stress tolerance has enjoyed few commercialization success stories. We typically source tolerance traits within crop species or in model plants that have either already lost their tolerance genes through successive breeding for yield and/or the plants never had those tolerance traits to begin with. The advent of high through-put sequencing now allows us to cast a wider net for finding tolerance traits and our approach exploits a wild crop-relative adapted to extreme conditions, an "extremophyte", to identify tolerance traits and their genetic basis. Eutrema salsugineum is a plant that is closely related to canola but thrives on highly saline, alkaline soil. We discovered that an ecotype found in the Yukon, Canada, displays exceptional tolerance to drought and it thrives on soil that has low levels of the essential plant nutrient, phosphate. In contrast, an ecotype from Shandong, China, is far less tolerant to both drought and low phosphate. This differential sensitivity offers a means of identifying the genetic basis conferring tolerance versus sensitivity to drought and low phosphate. We will deploy an exceptional genetic resource comprising 180 recombinant inbred mapping populations (RILs) that were produced by crossing Yukon and Shandong E. salsugineum parents. We will use a combination of Restriction site Associated DNA sequencing analysis of these RILs, bioinformatics, and down-stream validation by gene editing followed by phenotypic profiling to identify regions of genes in the E. salsugineum genome associated with efficient use of phosphate as an initial objective, and in a second objective, tolerance to water deficits. Typically, plants on low phosphate have shorter roots to forage more effectively for phosphate in upper soil layers where it is more plentiful. However, roots penetrating deeply into soil profiles are needed to reach receding water during drought. An intriguing feature of Yukon E. salsugineum is that a tolerance to low phosphate is not accompanied by shorter roots. Canada, like much of the world, is facing a future of drier overall summers and dwindling global supplies of accessible rock phosphate for fertilizers, a combination of challenges that Yukon E. salsugineum already copes with successfully in its natural habitat using traits we urgently need on the farm.

到2050年，世界人口预计将超过90亿。由于全球农业土地基础有限，我们在如何养活25亿多人口方面面临巨大的不确定性。我们必须用更少的土地生产更多的粮食，但同时面临的一个挑战是，不可预测的严重恶劣天气事件越来越频繁，这些情况已经导致产量损失和灾难性的作物歉收。我们必须找到更有效的方法来稳定产量，确保安全可靠的粮食供应，最好是减少灌溉、化肥和作物保护化学品等昂贵的投入。然而，研究确定性状，以提高作物的胁迫耐受性享有很少的商业化成功的故事。我们通常来源于作物物种或模式植物中的耐受性性状，所述模式植物或者已经通过连续育种丧失了它们的耐受性基因以获得产量，和/或所述植物从开始就不具有那些耐受性性状。高通量测序的出现现在使我们能够为寻找耐受性性状投下更广泛的网，并且我们的方法利用了适应极端条件的野生作物相对物，即“极端植物”，来鉴定耐受性性状及其遗传基础。Eutrema salsugineum是一种与卡诺拉密切相关的植物，但在高度盐碱化的土壤中茁壮成长。我们发现，在加拿大的育空地区发现的一种生态类型，表现出非凡的耐旱性，它在植物必需营养素磷酸盐含量低的土壤中茁壮成长。相比之下，来自中国山东的生态型对干旱和低磷的耐受性要差得多。这种不同的敏感性提供了一种手段，确定遗传基础赋予耐受性与敏感性干旱和低磷酸盐。我们将利用育空地区和山东鄂南杂交产生的180个重组自交作图群体（RILs）构建一个特殊的遗传资源。Salsugineum父母我们将结合使用这些RILs的限制性位点相关DNA测序分析、生物信息学和下游基因编辑验证，然后进行表型分析，以确定大肠杆菌中的基因区域。在本发明的一个实施方案中，本发明的目的是将与磷酸盐的有效利用相关的盐松基因组作为初始目标，并且在第二个目标中，对缺水的耐受性。通常，低磷植物的根较短，可以更有效地在上层土壤中寻找磷，因为那里的磷更丰富。然而，在干旱期间，需要根系深入土壤剖面以达到消退的水分。育空地区E. salsugineum的另一个特点是，对低磷酸盐的耐受性并不伴随着较短的根。加拿大，像世界上许多地方一样，正面临着一个干燥的整体夏季和减少全球供应的可获得的磷矿石肥料，一个组合的挑战，育空地区E。盐柳已经成功地在其自然栖息地利用我们在农场迫切需要的特性。