Background

Interactions of plants with biotic stress factors including bacteria, fungi, and viruses have been extensively investigated to date. Plasmodiophora brassicae, a protist pathogen, causes clubroot disease in Cruciferae plants. Infection of Chinese cabbage (Brassica rapa) plants with P. brassica results in the formation of root galls, which inhibits the roots from absorbing soil nutrients and water. Sugar, the major source of carbon for all living organisms including pathogens and host plants, plays an important role in plant growth and development.

Objective

To explore the roles of BrSWEET2, BrSWEET13, and BrSWEET14 in P. brassicae resistance, Arabidopsis thaliana T-DNA knockout mutants sweet2, sweet13, and sweet14 were employed.

Methods

To isolate total RNA from the collected root nodules, the root tissues washed several times with running water and frozen tissues with liquid nitrogen. Total RNA was extracted using the Spectrum™ Plant Total RNA Kit (SIGMA) and cDNA was synthesized in a 20 μl reaction volume using the ReverTra Ace-α-^® kit (TOYOBO). Real-time PCR was performed in a 10 μl reaction volume containing 1 μl of template DNA, 1 μl of forward primer, 1 μl of reverse primer, 5 μl of 2× iQTM SYBR^® Green Supermix (BioRad), and 2 μl of sterile distilled water. The SWEET genes were genotyped using BioFACT™ 2× TaqBasic PCR Master Mix 2.

Results

Both sweet2 and sweet14 showed strong resistance to P. brassicae compared with wild-type Arabidopsis and Chinese cabbage plants and sweet13 mutant plants. Pathogenicity assays indicated that the SWEET2 gene plays an important role in clubroot disease resistance in higher plants.

中文翻译：

---

白菜SWEET基因在对芸苔根霉的防御反应中的作用

背景

迄今为止，植物与细菌、真菌和病毒等生物胁迫因素的相互作用已得到广泛研究。甘蓝根肿菌是一种原生生物病原体，会在十字花科植物中引起根肿病。大白菜（Brassica rapa）植物被P.Brassica感染会导致根瘿的形成，从而抑制根部吸收土壤养分和水分。糖是包括病原体和宿主植物在内的所有生物体的主要碳源，在植物生长和发育中发挥着重要作用。

客观的

为了探索BrSWEET2、BrSWEET13和BrSWEET14在芥菜抗性中的作用，使用了拟南芥T-DNA 敲除突变体sweet2、sweet13和sweet14 。

方法

为了从收集的根瘤中分离总RNA，用流水清洗根组织数次，并用液氮冷冻组织。使用 Spectrum™ 植物总 RNA 试剂盒 (SIGMA) 提取总 RNA，并使用 ReverTra Ace-α- ^®试剂盒 (TOYOBO)在 20 μl 反应体积中合成 cDNA 。实时 PCR 在 10 μl 反应体积中进行，其中包含 1 μl 模板 DNA、1 μl 正向引物、1 μl 反向引物、5 μl 2× iQTM SYBR® ^Green Supermix (BioRad) 和 2 μl 无菌蒸馏水。使用 BioFACT™ 2× TaqBasic PCR Master Mix 2 对SWEET基因进行基因分型。

结果

与野生型拟南芥和大白菜植株及sweet13突变体植株相比，sweet2和sweet14均对十字花科植物表现出较强的抗性。致病性测定表明SWEET2基因在高等植物根肿病抗性中发挥重要作用。