Isolation and characterization of plant growth-promoting rhizobacteria and their effects on the growth ofMedicago sativaL. under salinity conditions
Isolation and characterization of plant growth-promoting rhizobacteria and their effects on the growth ofMedicago sativaL. under salinity conditions
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DOI：
10.1007/s10482-020-01434-1
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发表时间：
2020-06-20
影响因子：
2.6
通讯作者：
Ying, Hanjie
中科院分区：
文献类型：
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作者：
Zhu, Zhiyu;Zhang, Huanhuan;Ying, Hanjie
植物根际促生细菌是一类能够在植物根际定居并促进植物根系生长，从而提高植物对盐胁迫的科普能力的细菌。本研究的目的是（1）分离和鉴定具有高植物生长促进（PGP）潜力的生长素产生菌，（2）评价PGP对盐胁迫（130 mM NaCl）下苜蓿生长的影响。从13株分离菌株中筛选出巨大芽孢杆菌NRCB 001（NRCB 001）、B.枯草杆菌亚种枯草杆菌NRCB 002（NRCB 002）和B.枯草杆菌NRCB 003（NRCB 003）具有产生生长素的能力，其生长素的含量为47.53 ~ 154.38 μ g/ml。3株生长素产生菌均表现出多项PGP性状，如产铁载体和NH 3，ACC脱氨酶活性，解磷和解钾。NRCB 001、NRCB 002和NRCB 003在含1750 mM NaCl的LB培养基中也能存活。选择了三个耐盐的生长素产生菌株进行进一步的分析。在温室试验中，接种NRCB 001、NRCB 002和NRCB 003的苜蓿幼苗干重分别比未接种的对照幼苗增加24.1%、23.1%和38.5%，差异显著（P < 0.05）。在130 mMNaCl胁迫下，接种NRCB 002和NRCB 003的紫花苜蓿干重分别比未接种的对照提高了96.9%和71.6%（P < 0.05）。研究结果表明，具有PGP性状的NRCB 002和NRCB 003是开发生物肥料，特别是在盐胁迫条件下使用的有希望的候选菌株。
Plant growth-promoting rhizobacteria are a group of free-living bacteria that colonize plant rhizosphere and benefit plant root growth, thereby increasing host plant to cope with salinity induced stress. The aim of this study was to (1) isolate and characterize auxin-producing bacteria showing a high plant growth-promoting (PGP) potential, and (2) evaluate the PGP effects on the growth ofMedicago sativaL under salinity stress (130 mM NaCl). Of thirteen isolates,Bacillus megateriumNRCB001 (NRCB001),B. subtilissubsp. subtilisNRCB002 (NRCB002) andB. subtilisNRCB003 (NRCB003) had the ability to produce auxin, which ranged from 47.53 to 154.38 mu g ml(-1). The three auxin-producing bacterial strains were shown multiple PGP traits, such as producing siderophore and NH3, showing ACC deaminase activity, solubilize phosphate and potassium. Furthermore, NRCB001, NRCB002, and NRCB003 could survive in LB medium containing 1750 mM NaCl. The three auxin-producing with salinity tolerance strains were selected for further analyses. In greenhouse experiments, when inoculated with NRCB001, NRCB002 and NRCB003, dry weight of alfalfa significantly (P < 0.05) increased by 24.1%, 23.1% and 38.5% respectively, compared with those of non-inoculated control seedlings under normal growth condition. When inoculated with NRCB002 and NRCB003, dry weight of alfalfa significantly (P < 0.05) increased by 96.9 and 71.6% respectively, compared with those of non-inoculated control seedlings under 130 mM NaCl condition. Our results indicated that NRCB002 and NRCB003 having PGP traits are promising candidate strains to develop biofertilizers, especially used under salinity stress conditions.