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

根腐病是油菜的一种严重的土传病害。它于2003年首次在艾伯塔省被发现，并迅速从2003年的12个田间感染蔓延到2017年底的2700多个受感染的田地。根茎病原菌的感染导致肿瘤样根茎瘿的形成。这些虫瘿减少了受影响植物对水分和养分的吸收，大大降低了油菜籽作物的产量和品质。在一些虫害严重的地区，作物产量损失高达100%。Clubroot似乎也在向萨斯喀彻温省移动，并于2017年在商业油菜田得到证实，并且在马尼托巴省正在增加，强调了这种疾病对整个草原造成的威胁。有许多可能的原因导致棒根病的流行，包括轮作时间短，但也有气候变化（土壤温度升高可能更有利于病原体的发展）。迄今为止，最有效的管理策略是种植抗棒根病的油菜品种。不幸的是，最近出现了能够克服这种耐药性的新的病原体菌株。因此，需要一种综合的方法来管理根茎，将遗传抗性与精细的农艺实践结合起来。拟议的项目将采用一种新的遗传方法，而不是依靠传统的“主要基因”对疾病的抗性，旨在通过修改其生长素反应来增加油菜的非生物（干旱）和生物（根茎）抗性。我们实验室的初步工作表明，通过调节油菜和拟南芥的生长素信号可以抑制胆汁的发育。这种调节可能反过来激活应激反应途径，使植物对水分胁迫和根茎发育更有抵抗力。也可能有协同效应，因为根感染也会造成水分胁迫，因为根不再能够从土壤中吸收足够的水分。需要进行研究，以减轻与气候变化相关的甘蓝感染和干旱胁迫的潜在风险，为帮助维持加拿大油菜籽生产商的全球存在和影响力提供工具。

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.