The present study aimed to investigate the potential of simple sugars for use as protection agents in the control of tomato bacterial wilt caused by Ralstonia pseudosolanacearum. Based on the sugar assimilation patterns of the pathogen, four unassimilable sugars (L-arabinose, maltose, D-raffinose, and D-ribose) were selected from 10 representative sugars present in tomato root exudates. These sugars were evaluated for their effects on bacterial wilt using a tomato seedling bioassay. The application of 0.25% L-arabinose significantly reduced disease severity and was, thus, selected as a candidate for further evaluations in a pot experiment under glasshouse conditions. The results obtained showed that the disease suppressive effects of L-arabinose slightly increased at higher concentrations; drench treatments at 0.1, 0.25, and 0.5% reduced disease severity by ca. 48, 70, and 87%, respectively. The drench treatment with 0.5% L-arabinose significantly reduced the pathogen population in the rhizosphere and stem tissues of tomato plants without any antibacterial activity. Real-time reverse-transcription PCR revealed that the expression of salicylic acid-dependent and ethylene-dependent defense genes was significantly enhanced in the stem tissues of L-arabinose-treated tomato plants following the pathogen inoculation. These results suggest that soil drenching with L-arabinose effectively suppresses tomato bacterial wilt by preventing pathogen proliferation in the rhizosphere and stem tissues of tomato plants. This is the first study to report the potential of L-arabinose as a safe, eco-friendly, and cost-effective plant protection agent for the control of tomato bacterial wilt.

中文翻译：

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L-阿拉伯糖在控制番茄细菌性枯萎病中的潜在用途

本研究旨在研究单糖作为保护剂在防治由青枯病菌引起的番茄青枯病中的潜力。根据病原体的糖同化模式，从番茄根系分泌物中存在的 10 种代表性糖中选择了四种不可同化的糖（L-阿拉伯糖、麦芽糖、D-棉子糖和 D-核糖）。使用番茄幼苗生物测定法评估这些糖对青枯病的影响。0.25% L-阿拉伯糖的应用显着降低了疾病的严重程度，因此被选为温室条件下盆栽实验中进一步评估的候选者。所得结果表明，L-阿拉伯糖的疾病抑制作用在较高浓度下略有增加；在 0.1、0.25 和 0 下进行淋洗处理。疾病严重程度降低约 5%。分别为 48、70 和 87%。用 0.5% L-阿拉伯糖浸湿处理显着减少了番茄植株根际和茎组织中的病原体种群，但没有任何抗菌活性。实时逆转录 PCR 显示，在病原体接种后，L-阿拉伯糖处理的番茄植株茎组织中水杨酸依赖性和乙烯依赖性防御基因的表达显着增强。这些结果表明，用 L-阿拉伯糖浸透土壤可通过防止病原体在番茄植株根际和茎组织中增殖来有效抑制番茄青枯病。这是第一项报告 L-阿拉伯糖作为一种安全、环保且具有成本效益的植物保护剂用于控制番茄青枯病的潜力的研究。