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

根肿病是一种严重的油菜土传病害。它于2003年在阿尔伯塔省首次被发现，并从2003年的仅12个田间侵扰迅速蔓延到2017年底的2,700多个受侵扰的田间。根肿病病原体的感染导致肿瘤样根瘿的发展。这些虫瘿减少了受影响植物对水和养分的吸收，大大降低了油菜作物的产量和质量。 在一些严重受害的农田，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年在商业油菜田得到证实，并且在马尼托巴正在增加，强调了这种疾病在整个大草原上构成的威胁。 根肿病的流行率越来越高有许多可能的原因，包括轮伐期短，但也有气候变化（土壤温度升高可能对病原体的发育更有利）。 迄今为止，最有效的管理策略是种植抗根肿病的油菜品种。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，需要一种综合方法来管理根肿病，将遗传抗性与精细调整的农艺措施相结合。拟议的项目将采取一种新的遗传方法，而不是依赖于传统的“主基因”抗病性，旨在通过修改其生长素反应来提高油菜的非生物（干旱）和生物（根肿病）抗性。我们实验室的初步工作表明，在油菜和拟南芥中，通过调节生长素信号可以抑制瘿的发育。这种调节可能反过来激活应激反应途径，使植物更能抵抗水分胁迫和根肿病的发展。 也可能有协同效应，因为根肿病感染也会导致水分胁迫，因为根部不再能够从土壤中吸收足够的水分。 需要研究减轻与气候变化相关的根肿病感染和干旱胁迫的潜在风险，以提供工具，帮助维持加拿大油菜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.