title: Effect of plant age on endophytic bacterial diversity of balloon flower (Platycodon grandiflorum) root and their antimicrobial activities.
abstract: Balloon flower (Platycodon grandiflorum) is widely cultivated vegetable and used as a remedy for asthma in East Asia. Experiments were conducted to isolate endophytic bacteria from 1-, 3-, and 6-year-old balloon flower roots and to analyze the enzymatic, antifungal, and anti-human pathogenic activities of the potential endophytic biocontrol agents obtained. Total 120 bacterial colonies were isolated from the interior of all balloon flower roots samples. Phylogenetic analysis based on 16S rRNA gene sequences showed that the population of 'low G + C gram-positive bacteria' (LGCGPB) gradually increased 60.0-80.0% from 1 to 6 years balloon flower sample. On the other hand, maximum hydrolytic enzyme activity showing endophytic bacteria was under LGCGPB, among the bacterial strains, Bacillus sp. (BF1-1 and BF3-8), Bacillus sp. (BF1-2 and BF3-5), and Bacillus sp. (BF1-3, BF3-6, and BF6-4) showed maximum enzyme activities. Besides, Bacillus licheniformis (BF3-5 and BF6-6) and Bacillus pumilus (BF6-1) showed maximum antifungal activity against Phytophthora capsici, Fusarium oxysporum, Rhizoctonia solani, and Pythium ultimum. Moreover, Bacillus licheniformis was found in 3 and 6 years balloon flower roots, but Bacillus pumilus was found only in 6 years sample. It is presumed that older balloon flower plants invite more potential antifungal endophytes for there protection from plant diseases. In addition, Bacillus sp. (BF1-2 and BF3-5) showed maximum anti-human pathogenic activity. So, plant age is presumed to influence diversity of balloon flower endophytic bacteria.
authors.affiliation: Division of Applied Life Sciences (BK21 Program), Gyeongsang National University, Chinju 660-701, Republic of Korea.
authors.forename: Shah Md
authors.initials: SM
authors.lastname: Asraful Islam
authors.forename: Renukaradhya K
authors.initials: RK
authors.lastname: Math
authors.forename: Jong Min
authors.initials: JM
authors.lastname: Kim
authors.forename: Myoung Geun
authors.initials: MG
authors.lastname: Yun
authors.forename: Ji Joong
authors.initials: JJ
authors.lastname: Cho
authors.forename: Eun Jin
authors.initials: EJ
authors.lastname: Kim
authors.forename: Young Han
authors.initials: YH
authors.lastname: Lee
authors.forename: Han Dae
authors.initials: HD
authors.lastname: Yun
mesh_terms: D000900:Anti-Bacterial Agents / Q000302:isolation & purification / Q000494:pharmacology*; D000898:Antibiosis; D000935:Antifungal Agents / Q000302:isolation & purification / Q000494:pharmacology*; D001407:Bacillus / Q000145:classification / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D044822:Biodiversity; D058675:Brevibacillus / Q000145:classification / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D004269:DNA, Bacterial / Q000235:genetics; D004754:Enterobacter / Q000145:classification / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D016982:Micrococcus luteus / Q000145:classification / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D010572:Pest Control, Biological; D010802:Phylogeny; D010935:Plant Diseases / Q000382:microbiology; D018517:Plant Roots / Q000382:microbiology*; D031238:Platycodon / Q000254:growth & development / Q000382:microbiology*; D012336:RNA, Ribosomal, 16S / Q000032:analysis; D042162:Rhizobium tropici / Q000145:classification / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D017422:Sequence Analysis, DNA; D012988:Soil Microbiology; D013559:Symbiosis
chemical_list: D000900:Anti-Bacterial Agents; D000935:Antifungal Agents; D004269:DNA, Bacterial; D012336:RNA, Ribosomal, 16S