Transcriptional responses of wheat roots inoculated with Arthrobacter nitroguajacolicus to salt stress

Abstract

It is commonly accepted that bacteria actively interact with plant host and have beneficial effects on growth and adaptation and grant tolerance to various biotic and abiotic stresses. However, the mechanisms of plant growth promoting bacteria to communicate and adapt to the plant environment are not well characterized. Among the examined bacteria isolates from different saline soils, Arthrobacter nitroguajacolicus was selected as the best plant growth-promoting bacteria under salt stress. To study the effect of bacteria on wheat tolerance to salinity stress, bread wheat seeds were inoculated with A. nitroguajacolicus and grown under salt stress condition. Comparative transcriptome analysis of inoculated and un-inoculated wheat roots under salt stress showed up-regulation of 152 genes whereas 5 genes were significantly down-regulated. Many genes from phenylpropanoid, flavonoid and terpenoid porphyrin and chlorophyll metabolism, stilbenoid, diarylheptanoid metabolism pathways were differentially expressed within inoculated roots under salt stress. Also, a considerable number of genes encoding secondary metabolites such as phenylpropanoids was detected. They are known to take part in lignin biosynthesis of the cell wall as well as antioxidants.

Halo-tolerant plant growth promoting rhizobacteria for improving productivity and remediation of saline soils

“…Similarly, upregulation of HKT family antiporters has also been reported in wheat inoculated with Serratia sp. Sl-12 [52] , Arthrobacter nitroguajacolicus [39] and maize plants treated with Bacillus amyloliquefaciens SQR9 [36] under salinity stress. Detailing the response to salinity stress in wheat by the inoculation of Enterobacter cloacae SBP-8, Singh et al [53] reported upregulation of defense related proteins by 2065%, photosynthesis related proteins by 792% and ion transport associated proteins by 765%.…”

“… S. lycopersicum P. putida UW4 Expression of Toc GTPase Regulation of chloroplast import apparatus components [38] 13. Wheat Arthrobacter nitroguajacolicus Upregulation of AA0618700, AA0359620 , APX, GPX Expression of AA0410390, AA1982260, AA0412840 and AA1872340 Plant cell wall biosynthesis, phenylpropanoid biosynthetic pathway, glutathione-ascorbate cycle, modulation of celular osmotic balance, ROS scavenging activity [39] 14. Oryza sativa B. amyloliquefaciens SN13 Upregulation of NADP-Me2, EREBP, SOSI, BADH and SERK1 Repression of GIG and SAPK4 NADP-Me2, EREBP, SOSI, BADH and SERK1 Accumulation of MAPK5 Na + /H + antiporter system, plant growth and development, abiotic stress response, oxidative decarboxylation of L-malate, Ion homeostasis [40] 15.…”

“…Among the class of transcription factors (TFs), WRKY induces several adaption responses in plants against abiotic stresses [63] , [64] . Safdarian et al [39] reported the role of WRKY TFs in mitigating salinity and drought stress through modulation of osmotic balance, scavenging of ROS and triggering of stress related genes. The study also proved that inoculation of wheat with A. nitroguajacolicus had higher WRKY28 gene expression and promoted growth of the plants under salinity stress.…”

Drought Tolerant Wheat Varieties Enrich Seed Microbiomes For Beneficial Microbes Under Drought Conditions

“…Inoculation of A. nitroguajacolicus, the species of Arthrobacter whose 16S rRNA gene pro le is the most closely related to Ar. sp D4-14, into wheat increased the total dry weight by more than 200% in conditions of high salinity, a condition at often occurs in tandem with drought [65]. A. nitroguajacolicus demonstrated the ability to produce auxin, ACC deaminase, siderophores and solubilize phosphate [65].…”

Symbiotic nitrogen fixation and endophytic bacterial community structure in Bt-transgenic chickpea (Cicer arietinum L)

“…Several species of Streptomycetes and Bacillus cereus, B. subtilis, and B. amyloliquefaciens were well-known for their potential on plant growth promotion and biological control of phyto-pathogens. Bacterial isolates belonging to Arthrobacter conferred stress tolerance and promoted plant growth under salt stress 40 . Bt-chickpea deprived of such beneficial www.nature.com/scientificreports www.nature.com/scientificreports/ endophytic colonization may suffer under stressed field environment.…”