Shahzad Raheem, Waqas Muhammad, Khan Abdul Latif, Al-Hosni Khadija, Kang Sang-Mo, Seo Chang-Woo, Lee In-Jung
School of Applied Biosciences, Kyungpook National University , Daegu 41566 , Republic of Korea.
Department of Agriculture Extension , Buher 19290, Khyber Pakhtunkhwa , Pakistan.
Acta Biol Hung. 2017 Jun;68(2):175-186. doi: 10.1556/018.68.2017.2.5.
Bacterial endophytes from the phyllosphere and rhizosphere have been used to produce bioactive metabolites and to promote plant growth. However, little is known about the endophytes residing in seeds. This study aimed to isolate and identify seed-borne bacterial endophytes from rice and elucidate their potential for phytohormone production and growth enhancement. The isolated endophytes included Micrococcus yunnanensis RWL-2, Micrococcus luteus RWL-3, Enterobacter soli RWL-4, Leclercia adecarboxylata RWL-5, Pantoea dispersa RWL-6, and Staphylococcus epidermidis RWL-7, which were identified using 16S rRNA sequencing and phylogenetic analysis. These strains were analyzed for indoleacetic acid (IAA) production by using GC-MS and IAA was found in the range of 11.50 ± 0.77 μg ml to 38.80 ± 1.35 μg ml. We also assessed the strains for plant growth promoting potential because these isolates were able to produce IAA in pure culture. Most of the growth attributes of rice plants (shoot and root length, fresh and dry biomass, and chlorophyll content) were significantly increased by bacterial endophytes compared to the controls. These results show that IAA producing bacterial endophytes can improve hostplant growth traits and can be used as bio-fertilizers.
来自叶际和根际的细菌内生菌已被用于生产生物活性代谢物和促进植物生长。然而，对于存在于种子中的内生菌却知之甚少。本研究旨在从水稻中分离和鉴定种子携带的细菌内生菌，并阐明它们产生植物激素和促进生长的潜力。分离出的内生菌包括云南微球菌RWL-2、藤黄微球菌RWL-3、土壤肠杆菌RWL-4、解羧勒克菌RWL-5、分散泛菌RWL-6和表皮葡萄球菌RWL-7，通过16S rRNA测序和系统发育分析对其进行鉴定。使用气相色谱-质谱联用仪分析这些菌株的吲哚乙酸（IAA）产量，发现IAA的含量在11.50±0.77μg/ml至38.80±1.35μg/ml之间。由于这些分离株能够在纯培养物中产生IAA，我们还评估了它们促进植物生长的潜力。与对照相比，细菌内生菌显著提高了水稻植株的大多数生长特性（地上部和根的长度、鲜重和干重以及叶绿素含量）。这些结果表明，产生IAA的细菌内生菌可以改善宿主植物的生长性状，并可作为生物肥料使用。
