鞘氨醇单胞菌属（学名：Sphingomonas）为鞘脂单胞菌目鞘脂单胞菌科的一属好氧或兼性厌氧发酵型革兰氏阴性杆菌。无芽孢的直杆状菌。此属的模式种为少动鞘氨醇单胞菌(Sphingomonas paucimobilis)。
1、NEW Bing 的回答
根际微生物群落中的Sphingomonas是一种革兰氏阴性的细菌属，属于拟杆菌门，广泛分布在土壤、水体和植物根际中。Sphingomonas对植物有以下几种作用：
- 降解有机污染物。Sphingomonas能够利用多种有机污染物作为碳源和能源，如多环芳烃、农药、染料等，从而减少这些物质对植物和环境的危害12。例如，Sphingomonas sp. PAMC 26605能够降解土壤中的苯并[a]芘，一种致癌的多环芳烃3。
- 促进植物生长。Sphingomonas能够产生一些激素和代谢物，如吲哚乙酸、葡萄糖酸、葡萄糖胺等，这些物质能够刺激植物的根系发育，增加植物的生物量和产量。例如，Sphingomonas sp. LK11能够促进玉米和小麦的生长4。
- 抑制植物病原菌。Sphingomonas能够产生一些抗菌物质，如抗生素、细菌素、酚类化合物等，这些物质能够抑制或杀死一些植物病原菌，如青枯病菌、软腐病菌、立枯丝核菌等，从而提高植物的抗病性。
综上所述，Sphingomonas是一种对植物有益的根际微生物，它能够降解有机污染物、促进植物生长和抑制植物病原菌。
2、Chat GPT的回答
Sphingomonas 是一类广泛存在于土壤和水体中的革兰氏阴性细菌，它们在根际微生物群落中也扮演着重要的角色。以下是 Sphingomonas 可能对植物产生的一些作用：
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生防作用：一些 Sphingomonas 物种可以产生抗生素或抑制植物病原体的生长的化合物，有助于保护植物免受根际病害的侵害。
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有机物降解：Sphingomonas 物种以其出色的降解能力而闻名，它们能够分解多种有机化合物，包括多环芳烃、农药、有机废弃物等。这有助于改善土壤质地并提供植物所需的养分。
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生长促进：某些 Sphingomonas 物种可以产生植物生长激素，如吲哚乙酸，有助于促进植物的生长和发育。
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氮循环：Sphingomonas 细菌可以参与土壤中氮的硝化和反硝化过程，从而有助于提供植物所需的氮源。
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抗氧化作用：一些 Sphingomonas 物种具有抗氧化特性，可以帮助植物对抗氧化应激，提高其抵抗力，尤其是在逆境条件下。
需要注意的是，Sphingomonas 物种的确切作用可能因物种和环境条件而异。不同的 Sphingomonas 物种可能对植物产生不同的影响。因此，在研究和应用中，通常需要具体考虑 Sphingomonas 物种的种类和其与植物的相互作用，以更好地理解其在特定生态系统中的角色。
3、Sphingomonas sp. Hbc-6 alters physiological metabolism and recruits beneficial rhizosphere bacteria to improve plant growth and drought tolerance
Drought poses a serious threat to plant growth. Plant growth-promoting
bacteria (PGPB) have great potential to improve plant nutrition, yield, and
drought tolerance. Sphingomonas is an important microbiota genus that is
extensively distributed in the plant or rhizosphere. However, the knowledge of
its plant growth-promoting function in dry regions is extremely limited. In this
study, we investigated the effects of PGPB Sphingomonas sp. Hbc-6 on maize
under normal conditions and drought stress. We found that Hbc-6 increased
the biomass of maize under normal conditions and drought stress. For
instance, the root fresh weight and shoot dry weight of inoculated maize
increased by 39.1% and 34.8% respectively compared with non-inoculated
plant, while they increased by 61.3% and 96.3% respectively under drought
conditions. Hbc-6 also promoted seed germination, maintained stomatal
morphology and increased chlorophyll content so as to enhance
photosynthesis of plants. Hbc-6 increased antioxidant enzyme (catalase,
superoxide, peroxidase) activities and osmoregulation substances (proline,
soluble sugar) and up-regulated the level of beneficial metabolites
(resveratrol, etc.). Moreover, Hbc-6 reshaped the maize rhizosphere bacterial
community, increased its richness and diversity, and made the rhizosphere
bacterial community more complex to resist stress; Hbc-6 could also recruit
more potentially rhizosphere beneficial bacteria which might promote plant
growth together with Hbc-6 both under normal and drought stress. In short,
Hbc-6 increased maize biomass and drought tolerance through the above
ways. Our findings lay a foundation for exploring the complex mechanisms of
interactions between Sphingomonas and plants, and it is important that
Sphingomonas sp. Hbc-6 can be used as a potential biofertilizer in
agricultural production, which will assist finding new solutions for improving
the growth and yield of crops in arid areas.