Project description:Background: Limited data are available on aluminum (Al)-toxicity-induced alterations of gene profiles in woody plants. Seedlings of Al-tolerant Citrus sinensis and Al-intolerant Citrus grandis were fertigated with nutrient solution containing 0 and 1.0 mM AlCl3•6H2O. Thereafter, we investigated the Al-toxicity-induced alterations of transcriptomics in roots by RNA-Seq. Results: Using RNA-seq, we isolated 1293 (990) up- and 1377 (915) downregulated genes from Al-treated C. grandis (C. sinensis) roots. Clearly, gene expression was less affected by Al-toxicity in C. sinensis roots than in C. grandis ones. Several Al-toxicity-responsive genes homologous to known Al-tolerance genes: Al-activated malate transporter, multidrug and toxic compound extrusion (MATE), IRON REGULATED/ferroportin 1, sensitive to proton rhizotoxicity 1 and monogalactosyldiacylglycerol synthase were identified in citrus roots. However, Al-induced upregulation of all these genes was stronger in C. grandis roots than in C. sinensis ones except for MATEs. Genes related to signal transduction, and sulfur transport and metabolism might also play a role in the higher Al-tolerance of C. sinensis. Conclusions: This is the first comparative investigation of transcriptomic responses in Al-treated citrus roots. There were common and unique mechanisms for citrus Al-tolerance. These results provide a platform for further investigating the roles of genes possibly responsible for citrus Al-tolerance.
Project description:Background: Limited data are available on aluminum (Al)-toxicity-induced alterations of gene profiles in woody plants. Seedlings of Al-tolerant Citrus sinensis and Al-intolerant Citrus grandis were fertigated with nutrient solution containing 0 and 1.0 mM AlCl3â?¢6H2O. Thereafter, we investigated the Al-toxicity-induced alterations of transcriptomics in roots by RNA-Seq. Results: Using RNA-seq, we isolated 1293 (990) up- and 1377 (915) downregulated genes from Al-treated C. grandis (C. sinensis) roots. Clearly, gene expression was less affected by Al-toxicity in C. sinensis roots than in C. grandis ones. Several Al-toxicity-responsive genes homologous to known Al-tolerance genes: Al-activated malate transporter, multidrug and toxic compound extrusion (MATE), IRON REGULATED/ferroportin 1, sensitive to proton rhizotoxicity 1 and monogalactosyldiacylglycerol synthase were identified in citrus roots. However, Al-induced upregulation of all these genes was stronger in C. grandis roots than in C. sinensis ones except for MATEs. Genes related to signal transduction, and sulfur transport and metabolism might also play a role in the higher Al-tolerance of C. sinensis. Conclusions: This is the first comparative investigation of transcriptomic responses in Al-treated citrus roots. There were common and unique mechanisms for citrus Al-tolerance. These results provide a platform for further investigating the roles of genes possibly responsible for citrus Al-tolerance. Examination of mRNA levels in control and Al-treatment roots of C. grandis and C. sinensis with two biological replicates were generated by deep sequencing, using Illumina HiSeq 2000 device.
Project description:Background: The soil environment is responsible for sustaining most terrestrial plant life on earth, yet we know surprisingly little about the important functions carried out by diverse microbial communities in soil. Soil microbes that inhabit the channels of decaying root systems, the detritusphere, are likely to be essential for plant growth and health, as these channels are the preferred locations of new root growth. Understanding the microbial metagenome of the detritusphere and how it responds to agricultural management such as crop rotations and soil tillage will be vital for improving global food production. Methods: The rhizosphere soils of wheat and chickpea growing under + and - decaying root were collected for metagenomics sequencing. A gene catalogue was established by de novo assembling metagenomic sequencing. Genes abundance was compared between bulk soil and rhizosphere soils under different treatments. Conclusions: The study describes the diversity and functional capacity of a high-quality soil microbial metagenome. The results demonstrate the contribution of the microbiome from decaying root in determining the metagenome of developing root systems, which is fundamental to plant growth, since roots preferentially inhabit previous root channels. Modifications in root microbial function through soil management, can ultimately govern plant health, productivity and food security.
Project description:Background: Magnesium (Mg)-deficiency occurs most frequently in strongly acidic, sandy soils. Citrus are grown mainly on acidic and strong acidic soils. Mg-deficiency causes poor fruit quality and low fruit yield in some Citrus orchards. For the first time, we investigated Mg-deficiency-responsive miRNAs in ‘Xuegan’ (Citrus sinensis) roots using Illumina sequencing in order to obtain some miRNAs presumably responsible for Citrus Mg-deficiency tolerance. Results: We obtained 101 (69) miRNAs with increased (decreased) expression from Mg-starved roots. Our results suggested that the adaptation of Citrus roots to Mg-deficiency was related to the several aspects: (a) inhibiting root respiration and related gene expression via inducing miR158 and miR2919; (b) enhancing antioxidant system by down-regulating related miRNAs (miR780, miR6190, miR1044, miR5261 and miR1151) and the adaptation to low-phosphorus (miR6190); (c) activating transport-related genes by altering the expression of miR6190, miR6485, miR1044, miR5029 and miR3437; (d) elevating protein ubiquitination due to decreased expression levels of miR1044, miR5261, miR1151 and miR5029; (e) maintaining root growth by regulating miR5261, miR6485 and miR158 expression; and (f) triggering DNA repair (transcription regulation) by regulating miR5176 and miR6485 (miR6028, miR6190, miR6485, miR5621, miR160 and miR7708) expression. Mg-deficiency-responsive miRNAs involved in root signal transduction also had functions in Citrus Mg-deficiency tolerance. Conclusions: We obtained several novel Mg-deficiency-responsive miRNAs (i.e., miR5261, miR158, miR6190, miR6485, miR1151 and miR1044) possibly contributing to Mg-deficiency tolerance. These results revealed some novel clues on the miRNA-mediated adaptation to nutrient deficiencies in higher plants.