Bacillus amyloliqueliciens FZB42 is a plant growth-promoting rhizobacteria (PGPR) that promotes plant growth, improves disease resistance, drought and salt tolerance abilities. However, there are few reports on the growth, biofilm formation, root colonization ability and exoposaccharides production of B. amyloliquefaciens FZB42 under drought stress. In this study, PEG-6000 was used to simulate drought stress, and the osmotic potentials were -0.05, -0.50, -1.48 and -2.95 MPa, respectively. The growth, biofilm formation, rhizosphere colonization ability and extracellular polysaccharide yield of B. amyloliquefaciens FZB42 under different concentrations of PEG-6000 were determined. This paper provided a theoretical basis for improving the drought resistance of plants by B. amyloliquefaciens FZB42. The results showed that: (1) High concentration of PEG-6000 can significantly inhibit the growth, biofilm formation and colonization ability of B. amyloliquefaciens FZB42 in Arabidopsis rhizosphere. When 15% PEG-6000 was added, the OD600 and numbers in the rhizosphere reached the lowest values of 1.542 and 1 500 cfu·mm-1, respectively. (2) The production of exoposaccharides of B. amyloliquefaciens FZB42 increased significantly with the increasement of PEG-6000 concentration. When there was none PEG-6000, the extracellular polysaccharide content was the lowest at 150.2 mg·L-1. When 15% PEG-6000 was added, the yield of extracellular polysaccharide was the highest at 568.8 mg·L-1.
[1] 赵舒曼,左洪超,卫翔谦.干旱区地膜覆盖农田下垫面对东亚气候效应的数值模拟[J].干旱区研究,2018,35(6):1363-1372.
[2] Wilhite D A.Drought:A Global Assessment[M].London,UK:Routledge Publishers,2000:3-18.
[3] Mittler R,Blumwald E.Genetic engineering for modern agriculture:challenges and perspectives[J].Annual Review of Plant Biology,2010,61:443-462.
[4] Yoshida T,Mogami J,Yamaguchi-Shinozaki K.ABA-dependent and ABA-independent signaling in response to osmotic stress in plants[J].Current Opinion in Plant Biology,2014,21:133-139.
[5] Pinheiro C,Chaves M.Photosynthesis and drought:can we make metabolic connections from available data?[J].Journal of Experimental Botany,2010,62(3):869-882.
[6] Todaka D,Zhao Y,Yoshida T,et al.Temporal and spatial changes in gene expression,metabolite accumulation and phytohormone content in rice seedlings grown under drought stress conditions[J].The Plant Journal,2017,90(1):61-78.
[7] Liu F,Xing S,Ma H,et al.Cytokinin-producing, plant growth-promoting rhizobacteria that confer resistance to drought stress in Platycladus orientalis container seedlings[J].Applied Microbiology and Biotechnology,2013,97(20):9155-9164.
[8] Cho S M,Kang B R,Kim Y C.Transcriptome analysis of induced systemic drought tolerance elicited by Pseudomonas chlororaphis O6 in Arabidopsis thaliana[J].The Plant Pathology Journal,2013,29(2):209-220.
[9] Timmusk S,Wagner E G H.The plant-growth-promoting rhizobacterium Paenibacillus polymyxa induces changes in Arabidopsis thaliana gene expression:a possible connection between biotic and abiotic stress responses[J].Molecular Plant Microbe Interactions,1999,12(11):951-959.
[10] Danhorn T,Fuqua C.Biofilm formation by plant-associated bacteria[J].Annual Review of Microbiology,2007,61:401-422.
[11] Branda S S,Vik S,Friedman L,et al.Biofilms:the matrix revisited[J].Trends in Microbiology,2005,13(1):20-26.
[12] Bianciotto V,Andreotti S,Balestrini R,et al.Mucoid mutants of the biocontrol strain Pseudomonas fluorescens CHA0 show increased ability in biofilm formation on mycorrhizal and nonmycorrhizal carrot roots[J].Molecular Plant Microbe Interactions,2001,14(2):255-260.
[13] Rodríguez-Navarro D N,Dardanelli M S,Ruíz-Saínz J E.Attachment of bacteria to the roots of higher plants[J].FEMS Microbiology Letters,2007,272(2):127-136.
[14] Webb J S,Givskov M,Kjelleberg S.Bacterial biofilms:prokaryotic adventures in multicellularity[J].Current Opinion in Microbiology,2003,6(6):578-585.
[15] Mielich-Süss B,Lopez D.Molecular mechanisms involved in Bacillus subtilis biofilm formation[J].Environmental Microbiology,2015,17(3):555-565.
[16] Zhang N,Wang D,Liu Y,et al.Effects of different plant root exudates and their organic acid components on chemotaxis,biofilm formation and colonization by beneficial rhizosphere-associated bacterial strains[J].Plant and Soil,2014,374(1/2):689-700.
[17] Wang C J,Yang W,Wang C,et al.Induction of drought tolerance in cucumber plants by a consortium of three plant growth-promoting rhizobacterium strains[J]. PLoS One,2012,7(12):e52565.
[18] Calvo-Polanco M,Sánchez-Romera B,Aroca R,et al.Exploring the use of recombinant inbred lines in combination with beneficial microbial inoculants (AM fungus and PGPR) to improve drought stress tolerance in tomato[J].Environmental and Experimental Botany,2016,131:47-57.
[19] Tiwari S,Prasad V,Chauhan P S,et al.Bacillus amyloliquefaciens confers tolerance to various abiotic stresses and modulates plant response to phytohormones through osmoprotection and gene expression regulation in rice[J].Frontiers in Plant Science,2017,8:1510.
[20] 刘少芳,王若愚.植物根际促生细菌提高植物耐盐性研究进展[J].中国沙漠,2019,39(2):1-12.
[21] Xie S,Jiang H,Ding T,et al.Bacillus amyloliquefaciens FZB42 represses plant miR846 to induce systemic resistance via a jasmonic acid-dependent signalling pathway[J].Molecular Plant Pathology,2018,19(7):1612-1623.
[22] Chen X H,Koumoutsi A,Scholz R,et al.Comparative analysis of the complete genome sequence of the plant growth-promoting bacterium Bacillus amyloliquefaciens FZB42[J].Nature Biotechnology,2007,25(9):1007-1014.
[23] Gao T,Greenwich J,Li Y,et al.The bacterial tyrosine kinase activator TkmA contributes to biofilm formation largely independent of the cognate kinase PtkA in Bacillus subtilis[J].Journal of Bacteriology,2015:438.
[24] Sarkar S,Marcos M P.D-amino acids do not inhibit biofilm formation in Staphylococcus aureus[J].PLoS One,2015,10(2):e0117613.
[25] Lu X,Liu S F,Yue L,et al.EpsC involved in the encoding of exopolysaccharides produced by Bacillus amyloliquefaciens FZB42 act to boost the drought tolerance of Arabidopsis thaliana[J].International Journal of Molecular Sciences,2018,19(12):3795.
[26] 王文洁,唐炜,俞玲娜,等.蒽酮-硫酸法与苯酚-硫酸法测定凉粉草多糖的比较[J].食品科技,2017(9):274-279.
[27] Idris E E,Iglesias D J,Talon M,et al.Tryptophan-dependent production of indole-3-Acetic Acid (IAA) affects level of plant growth promotion by Bacillus amyloliquefaciens FZB42[J].Molecular Plant Microbe Interactions,2007,20(6):619-626.
[28] Silambarasan S,Logeswari P,Cornejo P,et al.Evaluation of the production of exopolysaccharide by plant growth promoting yeast Rhodotorula sp. strain CAH2 under abiotic stress conditions[J]. International Journal of Biological Macromolecules,2019,121:55-62.
[29] John A L.Exopolysaccharides in plant-bacterial interactions[J].Annual Reviews in Microbiology,1992,46:307-346.
[30] Sutherland I W.Bacterial surface polysaccharides:structure and function[J].International Review of Cytology,1988,113:187-231.
[31] Rodriguez-Navarro D N,Dardanelli M S,Ruiz-Sainz J E.Attachment of bacteria to the roots of higher plants[J].FEMS Microbiology Letters,2007,272(2):127-136.
[32] 刘洋,刘琳,邹媛媛,等.与植物联合的细菌生物膜及其形成机制的研究进展[J].自然科学进展,2009,19(9):896-905.
[33] Rillig M C,Mummey D L.Mycorrhizas and soil structure[J].New Phytologist,2006,171(1):41-53.
[34] 陈军,戴俊英.水分胁迫下玉米叶片光合作用、脂质过氧化及超微结构变化的关系[J].玉米科学,1994,2(4):36-40.
[35] Bashan Y,Holguin G,De-Bashan L E.Azospirillum-plant relationships:physiological,molecular,agricultural,and environmental advances (1997-2003)[J].Canadian Journal of Microbiology,2004,50(8):521-577.
