Phosphorus-solubilizing bacteria can colonize the surface of plant roots under natural conditions and may enter plant tissues to form endophytic symbiosis. They can convert unavailable phosphorus in the soil into available phosphorus, which can be utilized by plants. The aims of this study were to investigate the chemotaxis of Bacillus cereus YL6 and its migration and colonization sites in Chinese cabbage and to provide some technical support for the subsequent investigation of the physiological regulation mechanism of phosphate-dissolving bacteria in plants. This study demonstrated that the green fluorescent protein marker did not affect the physiological and biochemical properties of YL6. Through the chemotaxis test and pot experiment, the colonization and growth promoting mechanism of YL6 in Chinese cabbage was explored. YL6 showed a strong positive chemotactic response to cabbage roots. The addition of organic acids to the soil promotes the colonization of YL6 in Chinese cabbage roots. Colonization of YL6 in Chinese cabbage is a dynamic process that moves from the root surface to root tissues and then up to stems and leaves. Fluorescence microscopy showed that YL6 mainly colonized cortical cells and vascular bundles of various plant tissues and was also observed in mesophyll cells. The proliferative effect of YL6 resulted from the interaction of effective phosphorus, and exuded auxin and gibberellin in the rhizosheath. This study enhanced our understanding of the interaction mechanisms between phosphate-dissolving bacteria YL6 and Chinese cabbage. YL6 has the potential for future development into bio-fertilizer for agricultural production.

中文翻译：

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蜡样芽孢杆菌YL6的趋化性及其对大白菜幼苗的定殖

溶磷菌可在自然条件下定植于植物根系表面，并可能进入植物组织形成内生共生。它们可以将土壤中不可利用的磷转化为可被植物利用的有效磷。本研究旨在研究蜡样芽孢杆菌YL6在大白菜中的趋化性及其迁移定植位点，为后续植物中溶磷菌生理调控机制的研究提供一定的技术支持。该研究表明绿色荧光蛋白标记物不影响 YL6 的生理和生化特性。通过趋化性试验和盆栽试验，探讨了YL6在大白菜中的定殖促生长机制。YL6 对甘蓝根表现出强烈的正向趋化反应。土壤中有机酸的添加促进了YL6在大白菜根部的定植。YL6 在大白菜中的定植是一个动态过程，从根表面移动到根组织，再到茎和叶。荧光显微镜显示YL6主要定植于各种植物组织的皮层细胞和维管束中，也在叶肉细胞中观察到。YL6 的增殖作用是由有效磷相互作用产生的，并在根鞘中渗出生长素和赤霉素。本研究加深了我们对溶磷菌 YL6 与大白菜相互作用机制的理解。YL6 具有未来发展成为农业生产生物肥料的潜力。