scholarly journals Diversity of Bacterial Microbiota of Coastal Halophyte Limonium sinense and Amelioration of Salinity Stress Damage by Symbiotic Plant Growth-Promoting Actinobacterium Glutamicibacter halophytocola KLBMP 5180

2018 ◽  
Vol 84 (19) ◽  
Author(s):  
Sheng Qin ◽  
Wei-Wei Feng ◽  
Yue-Ji Zhang ◽  
Tian-Tian Wang ◽  
You-Wei Xiong ◽  
...  

ABSTRACT Plant-associated microorganisms are considered a key determinant of plant health and growth. However, little information is available regarding the composition and ecological function of the roots' and leaves' bacterial microbiota of halophytes. Here, using both culture-dependent and culture-independent techniques, we characterized the bacterial communities of the roots and leaves as well as the rhizosphere and bulk soils of the coastal halophyte Limonium sinense in Jiangsu Province, China. We identified 49 representative bacterial strains belonging to 17 genera across all samples, with Glutamicibacter as the most dominant genus. All Glutamicibacter isolates showed multiple potential plant growth promotion traits and tolerated a high concentration of NaCl and a wide pH range. Interestingly, further inoculation experiments showed that the Glutamicibacter halophytocola strain KLBMP 5180 isolated from root tissue significantly promoted host growth under NaCl stress. Indeed, KLBMP 5180 inoculation increased the concentrations of total chlorophyll, proline, antioxidative enzymes, flavonoids, K+, and Ca2+ in the leaves; the concentrations of malondialdehyde (MDA) and Na+ were reduced. A transcriptome analysis identified 1,359 and 328 differentially expressed genes (DEGs) in inoculated seedlings treated with 0 and 250 mM NaCl, respectively. We found that pathways related to phenylpropanoid and flavonoid biosynthesis and ion transport and metabolism might play more important roles in host salt stress tolerance induced by KLBMP 5180 inoculation compared to that in noninoculated leaves. Our results provide novel insights into the complex composition and function of the bacterial microbiota of the coastal halophyte L. sinense and suggest that halophytes might recruit specific bacteria to enhance their tolerance of harsh environments. IMPORTANCE Halophytes are important coastal plants often used for the remediation of saline coastal soils. Limonium sinense is well known for its medical properties and phytoremediation of saline soils. However, excessive exploitation and utilization have made the wild resource endangered. The use of endophytic and rhizosphere bacteria may be one of the suitable ways to solve the problem. This study was undertaken to develop approaches to improve the growth of L. sinense using endophytes. The application of actinobacterial endophytes ameliorated salt stress damage of the host via complex physiological and molecular mechanisms. The results also highlight the potential of using habitat-adapted, symbiotic, indigenous endophytic bacteria to enhance the growth and ameliorate abiotic stress damage of host plants growing in special habitats.

2020 ◽  
Vol 9 (18) ◽  
Author(s):  
Sudipta Dutta ◽  
Amena Khatun ◽  
Dipali Rani Gupta ◽  
Musrat Zahan Surovy ◽  
M. Mahbubur Rahman ◽  
...  

Serratia marcescens strain BTL07, which has the ability to promote growth and suppress plant diseases, was isolated from the rhizoplane of a chili plant. The draft genome sequence data of the strain will contribute to advancing our understanding of the molecular mechanisms underlying plant growth promotion and tolerance to different stresses.


2021 ◽  
Vol 7 (12) ◽  
Author(s):  
Roberto Siani ◽  
Georg Stabl ◽  
Caroline Gutjahr ◽  
Michael Schloter ◽  
Viviane Radl

Beta-proteobacteria belonging to the genus Acidovorax have been described from various environments. Many strains can interact with a range of hosts, including humans and plants, forming neutral, beneficial or detrimental associations. In the frame of this study, we investigated the genomic properties of 52 bacterial strains of the genus Acidovorax , isolated from healthy roots of Lotus japonicus, with the intent of identifying traits important for effective plant-growth promotion. Based on single-strain inoculation bioassays with L. japonicus, performed in a gnotobiotic system, we distinguished seven robust plant-growth promoting strains from strains with no significant effects on plant-growth. We showed that the genomes of the two groups differed prominently in protein families linked to sensing and transport of organic acids, production of phytohormones, as well as resistance and production of compounds with antimicrobial properties. In a second step, we compared the genomes of the tested isolates with those of plant pathogens and free-living strains of the genus Acidovorax sourced from public repositories. Our pan-genomics comparison revealed features correlated with commensal and pathogenic lifestyle. We showed that commensals and pathogens differ mostly in their ability to use plant-derived lipids and in the type of secretion-systems being present. Most free-living Acidovorax strains did not harbour any secretion-systems. Overall, our data indicate that Acidovorax strains undergo extensive adaptations to their particular lifestyle by horizontal uptake of novel genetic information and loss of unnecessary genes.


2021 ◽  
Vol 138 ◽  
pp. 94-104
Author(s):  
Guendouz Dif ◽  
Hadj Ahmed Belaouni ◽  
Yacine Goudjal ◽  
Amine Yekkour ◽  
Nadjette Djemouai ◽  
...  

2014 ◽  
Vol 82 (5) ◽  
pp. 1744-1754 ◽  
Author(s):  
Tram N. Cao ◽  
Zhuyun Liu ◽  
Tran H. Cao ◽  
Kathryn J. Pflughoeft ◽  
Jeanette Treviño ◽  
...  

ABSTRACTDespite the public health challenges associated with the emergence of new pathogenic bacterial strains and/or serotypes, there is a dearth of information regarding the molecular mechanisms that drive this variation. Here, we began to address the mechanisms behind serotype-specific variation between serotype M1 and M3 strains of the human pathogenStreptococcus pyogenes(the group AStreptococcus[GAS]). Spatially diverse contemporary clinical serotype M3 isolates were discovered to contain identical inactivating mutations within genes encoding two regulatory systems that control the expression of important virulence factors, including the thrombolytic agent streptokinase, the protease inhibitor-binding protein-G-related α2-macroglobulin-binding (GRAB) protein, and the antiphagocytic hyaluronic acid capsule. Subsequent analysis of a larger collection of isolates determined that M3 GAS, since at least the 1920s, has harbored a 4-bp deletion in thefasCgene of thefasBCAXregulatory system and an inactivating polymorphism in therivRregulator-encoding gene. ThefasCandrivRmutations in M3 isolates directly affect the virulence factor profile of M3 GAS, as evident by a reduction in streptokinase expression and an enhancement of GRAB expression. Complementation of thefasCmutation in M3 GAS significantly enhanced levels of the small regulatory RNA FasX, which in turn enhanced streptokinase expression. Complementation of therivRmutation in M3 GAS restored the regulation ofgrabmRNA abundance but did not alter capsule mRNA levels. While important, thefasCandrivRmutations do not provide a full explanation for why serotype M3 strains are associated with unusually severe invasive infections; thus, further investigation is warranted.


Agronomy ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 888
Author(s):  
Giorgia Novello ◽  
Patrizia Cesaro ◽  
Elisa Bona ◽  
Nadia Massa ◽  
Fabio Gosetti ◽  
...  

The reduction of chemical inputs due to fertilizer and pesticide applications is a target shared both by farmers and consumers in order to minimize the side effects for human and environmental health. Among the possible strategies, the use of biostimulants has become increasingly important as demonstrated by the fast growth of their global market and by the increased rate of registration of new products. In this work, we assessed the effects of five bacterial strains (Pseudomonas fluorescens Pf4, P. putida S1Pf1, P. protegens Pf7, P. migulae 8R6, and Pseudomonas sp. 5Vm1K), which were chosen according to their previously reported plant growth promotion traits and their positive effects on fruit/seed nutrient contents, on a local onion cultivar and on zucchini. The possible variations induced by the inoculation with the bacterial strains on the onion nutritional components were also evaluated. Inoculation resulted in significant growth stimulation and improvement of the mineral concentration of the onion bulb, induced particularly by 5Vm1K and S1Pf1, and in different effects on the flowering of the zucchini plants according to the bacterial strain. The present study provides new information regarding the activity of the five plant growth-promoting bacteria (PGPB) strains on onion and zucchini, two plant species rarely considered by the scientific literature despite their economic relevance.


Author(s):  
Wei Cheng ◽  
Xuejing Yu ◽  
Xingguo Wang

Herbaspirillum camelliae WT00C, as a tea-plant endophytic bacterium, not only colonizes specifically in tea plants but also promotes tea-plant growth and selenium enrichment. Different from diazotrophic endophytes H. seropedicae, H. frisingense and H. rubrisubalbicans, H. camelliae WT00C does not display nitrogen-fixing activity. To understand the molecular mechanisms of promoting the growth of tea plant and Se-enrichment, we sequenced and annotated the genome of H. camelliae WT00C. The results showed that the genome was composed of 6,079,821 base pairs with a total of 5,537 genes. The genomic survey also revealed that H. camelliae WT00C was a multifunctional bacterium metabolizing a variety of carbon and nitrogen sources and defending against biotic and abiotic stress. Although this bacterium did not have intact nitrogen-fixing genes, its genome held the genes responsible for indole-3-acetic acid (IAA) biosynthesis, 1-aminocyclopropane-1-carboxylate (ACC) deamination, siderophore synthesis, ammonia formation, urea metabolism, glutathione and selenocompound metabolisms. Biosynthesis of IAA, siderophore, ammonia, urea and ACC deaminase could explain why two bacterial strains promote tea-plant growth and development. Selenocompound metabolism in this bacterium might also benefit tea-plant growth and Se-enrichment. In addition, the genome of H. camelliae also contained a multitude of protein secretion systems T1SS, T3SS, T4SS and T6SS, in which T4SS did not exhibit in other members of the genus Herbaspirillum.


2012 ◽  
Vol 194 (23) ◽  
pp. 6649-6650 ◽  
Author(s):  
Ju Yeon Song ◽  
Min-Jung Kwak ◽  
Kwang Youll Lee ◽  
Hyun Gi Kong ◽  
Byung Kwon Kim ◽  
...  

ABSTRACTBurkholderia pyrrociniaCH-67 was isolated from forest soil as a biocontrol agent to be utilized in agriculture. Here, we report the 8.05-Mb draft genome sequence of this bacterium. Its genome contains genes involved in biosynthesis of secondary metabolites and plant growth promotion, which may contribute to probiotic effects on plants.


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