Increasing abiotic (drought) and biotic (clubroot) resistance in Brassica species (Arabidopsis and Canola) by modifying auxin response

油菜根腐病是油菜作物的一种严重土传病害。它于2003年在艾伯塔省首次被发现，并迅速蔓延，从2003年的12次田间侵扰到2017年底的2700多块被侵扰的田地。根瘤病原菌的侵染会导致根瘤形成。这些虫害减少了受影响植物对水分和养分的吸收，极大地降低了油菜作物的产量和质量。在一些重灾区，作物产量损失达100%。Clubroot似乎也正在进入萨斯喀彻温省，并于2017年在商业油菜籽田得到确认，而且在马尼托巴省正在增加，这突显了这种疾病在整个草原上构成的威胁。根瘤病的流行增加有许多可能的原因，包括短轮作，但也有气候变化(土壤温度升高可能更有利于病原菌的发展)。到目前为止，最有效的管理策略是种植抗根瘤病的油菜品种。不幸的是，最近出现了新的病原体菌株，可以克服这种耐药性。因此，需要一种综合的方法来管理根瘤病，将遗传抗性与微调的农艺措施结合起来。拟议的项目将采用一种新的遗传方法，而不是依赖于传统的主基因抗病，目的是通过改变油菜的生长素反应来提高其对非生物(干旱)和生物(丛生)的抗性。我们实验室的初步工作表明，可以通过调节油菜和拟南芥中的生长素信号来抑制胆汁的发育。这种调节可能反过来激活胁迫反应途径，使植物对水分胁迫和根茎发育都更具抵抗力。也可能存在协同效应，因为根瘤病感染也会造成水分胁迫，因为根部不再能够从土壤中吸收足够的水分。需要进行研究，以减轻与气候变化有关的根瘤病感染和干旱胁迫的严重潜在风险，以提供工具，帮助维持加拿大油菜籽生产商的全球存在和影响力。

Clubroot is a serious soilborne disease of canola crops. It was first detected in Alberta in 2003, and it spread quickly from just 12 field infestations in 2003 to more than 2,700 infested fields by the end of 2017. Infection by the clubroot pathogen results in the development of tumor-like root galls. These galls reduce water and nutrient uptake by the affected plants, greatly reducing the yield and quality of canola crops. In some heavily infested fields, the crop yield loss was 100%. Clubroot also appears to be moving into Saskatchewan and was confirmed in commercial canola fields in 2017, and it is increasing in Manitoba, underscoring the threat posed by this disease across the Prairies. There are number of possible reasons for the increasing prevalence of clubroot, including short rotations, but also climate change (increased soil temperatures may be more optimal for pathogen development). To date, the most effective management strategy has been the planting of clubroot resistant canola varieties. Unfortunately, new strains of the pathogen have emerged recently which can overcome this resistance. Therefore, an integrated approach to clubroot management is needed that integrates genetic resistance with finely-tuned agronomic practices. The proposed project will take a novel genetic approach, which rather than relying on traditional 'major gene' resistance to disease, aims to increase abiotic (drought) and biotic (clubroot) resistance in canola by modifying its auxin response. Preliminary work in our labs suggests that gall development can be suppressed by modulating auxin signaling in canola and Arabidopsis. This modulation may in turn activate stress-response pathways, making the plants more resistant to both water stress and clubroot development. There may also be synergistic effects, since the clubroot infection also causes water stress, as the roots are no longer able to take up sufficient water from the soil. Research to mitigate the serve potential risks of clubroot infection and drought stress associated with climate change is needed to provide tools to help maintain the global presence and influence of the Canadian canola producers.